MSFC engine
Jim Kingdon
> RLV is pretty much on track, and fending off the many agendas being
> brought to bear on them. (A few examples are the giant sucking
> sound of the MSFC engine design faction . . .
and someone asks by email what this "MSFC engine" is.
The official answer can be found at
http://rlv.msfc.nasa.gov/RLV_HTMLs/RLVTech.html; the program goes by
the name of "Long Term High Payoff Main Propulsion System".
The background is that there are bunch of MSFC engine designers who
spent the 70s designing the SSME, who spent the 80s designing SSME
upgrades, and now that the talk is of cutting back on shuttle upgrades
they are thinking maybe RLV needs a new engine and they are the people
to design it. I believe it was Henry Vanderbilt and/or the Space
Access Society who said they wanted a billion dollars to develop an
(all-new?) engine (but I can't seem to find the reference).
The RLV program seems to have redirected this urge away from an
unproductive direction (a big huge lengthy program to develop "the"
engine for RLV, mostly on paper) into a more or less productive one (a
series of technology demonstrations which involve building and testing
hardware).
OK, that's the situation as I understand it. I'm sure people with a
different perspective will be glad to flame^H^H^H^H^Hoffer their
perspective.
Jim Kingdon
> "on track". The X-33 program may be proceeding but that doen't
> equate to a downstream RLV program.
Ah, we have two serious differences in assumptions. One is that you
equate RLV with X-33. I don't--I think DC-XA, technology
demonstrations (TPS, etc.), etc., are at least as valuable as a X-33
flight vehicle. Two is that you are looking for "a downstream RLV
program". I am looking for "one or more downstream RLV programs".
Assuming there will be, or may very well be, several downstream
programs changes the focus--one demonstrates technologies that will be
useful (not just any old technologies, but including some
diversity--e.g. aerospikes *and* bell-nozzle engine work), and doesn't
worry quite so much about things like traceability to an operational
followon.
> And the consequence may well be that, in 1999, we wind up with no
> commercial financial support for a commercial RLV. We may just be proving
> technology for an improved multi-stage launch vehicle.
Nothing wrong with that. If the technology gets transferred to a
commercial launch vehicle, and it is an improvement, I would call the
program a resounding success.
Having potentially useful engines, not just designed (like an STME),
and not just built (like a J-2, F-1, etc.), but currently in
production, is *very* useful to any reusable launcher development.
The only reason DC-X was able to fly is that the RL-10 is used on
expendables. Likewise for all the X-33 proposals.
> If NASA just sits around until a program is needed. we wouldn't be
> ready to do anything when that happened. Just because we're thinking
> about such technology doesn't mean that we expect all such programs to
> be fully funded.
There are two problems with much of what NASA has done in the past.
One is that they focus on paper studies rather than building hardware.
Paper studies are fine for immature fields like interstellar travel,
but the time for paper studies in chemical rocket launchers is past.
Two is that all too much of NASA's study effort has been aimed at
specific unfunded programs. Instead one should develop technology
which could be used in more than one program (unfunded but plausible
is OK, commercial is another good choice). Does this mean design
compromises? Yes, often (although if the compromises are too great
one should look for a different set of potential applications). Does
it *greatly* increase the chance that such technologies will be useful
and not just collect dust? Yes.
Fortunately, NASA is changing for the better, on both counts
(technology demonstration instead of planning unfunded programs, and
building hardware rather than pushing paper).
Doug Hendrix
kin...@harvey.cyclic.com (Jim Kingdon) wrote:
>> RLV is pretty much on track, and fending off the many agendas being
>> brought to bear on them. (A few examples are the giant sucking
>> sound of the MSFC engine design faction . . .
>
Please explain what factors lead you to the conclusion that RLV is "on track".
The X-33 program may be proceeding but that doen't equate to a downstream RLV
program. The RLV won't be proven "on track" until about 1999 when we see if
any investment bankers are interested in investing some billions of dollars.
>and someone asks by email what this "MSFC engine" is.
>
>The official answer can be found at
>http://rlv.msfc.nasa.gov/RLV_HTMLs/RLVTech.html; the program goes by
>the name of "Long Term High Payoff Main Propulsion System".
>
MSFC has lots of long term, high payoff programs in work. These are
basically technology programs with not much money. You shouldn't anticipate
that that all such programs will mature. Some of you folk are a bit paranoid
about
this it seems. If NASA just sits around until a program is needed. we
wouldn't be ready to do anything when that happened. Just because we're
thinking about such technology doesn't mean that we expect all such progrmas
to be fully funded. If they were all fully funded, NASA's budget would have to
be a LOT bigger.
>The background is that there are bunch of MSFC engine designers who
>spent the 70s designing the SSME, who spent the 80s designing SSME
>upgrades, and now that the talk is of cutting back on shuttle upgrades
>they are thinking maybe RLV needs a new engine and they are the people
>to design it. I believe it was Henry Vanderbilt and/or the Space
>Access Society who said they wanted a billion dollars to develop an
>(all-new?) engine (but I can't seem to find the reference).
>
>The RLV program seems to have redirected this urge away from an
>unproductive direction (a big huge lengthy program to develop "the"
>engine for RLV, mostly on paper) into a more or less productive one (a
>series of technology demonstrations which involve building and testing
>hardware).
And the consequence may well be that, in 1999, we wind up with no
commercial financial support for a commercial RLV. We may just be proving
technology for an improved multi-stage launch vehicle. That's what I basically
think will be the case with present prolusion capabilities. That's the
Cathy Mancus
In article <4avs0r$2...@news.ro.com>, nhen...@ren.com (Doug Hendrix) writes:
> And the consequence may well be that, in 1999, we wind up with no
> commercial financial support for a commercial RLV. We may just be proving
> technology for an improved multi-stage launch vehicle.
Read my lips: RLV DOES NOT HAVE TO BE SSTO. Please stop confusing
two separate issues. There is a lot of room for cost reduction and
more routine operatoins even without SSTO.
I'm getting really tired of this assumption that SSTO is the only
path to RLV and a fully commercial market.
/-------------------------------------------------------------------\
| Catherine Mancus <ca...@zorac.cary.nc.us> |
| PP-SEL, N5WVR "God is a sponge." |
\-------------------------------------------------------------------/
Cathy Mancus
In article <4b51v2$d...@news.ro.com>, nhen...@ren.com (Doug Hendrix) writes:
>>In article <4avs0r$2...@news.ro.com>, nhen...@ren.com (Doug Hendrix) writes:
>>> And the consequence may well be that, in 1999, we wind up with no
>>> commercial financial support for a commercial RLV. We may just be proving
>>> technology for an improved multi-stage launch vehicle.
> In article <4b40s1$m...@brtph500.bnr.ca>, man...@bnr.ca (Cathy Mancus) wrote:
>> Read my lips: RLV DOES NOT HAVE TO BE SSTO. Please stop confusing
>>two separate issues. There is a lot of room for cost reduction and
>>more routine operations even without SSTO.
> READ MY LIPS: I've been there and done that on multi-stage RLV's, in about
> 1970-1971.
I think we have learned one or two things since 1971 (particularly in
materials science).
> If people gripe about the Shuttle, thank your stars that NASA
> didn't build one of the Flyback boosters/Flyback Orbiters that were
> considered. The problems were legion and guess what: WE HAVEN'T ADVANCED
> ENOUGH IN THE LAST 25 YEARS TO MAKE THOSE PROBLEMS MUCH EASIER.
For a vehicle of what size? Are you assuming hypersonic separation?
Have you considered vertical landing of the flyback booster? Are you
assuming optimal stage ratios? I think you have a particular view of what
your TSTO looks like, and are using it to block out alternatives.
You simply can't rule out all large-cost-reduction TSTO RLV's with a
sweep of your hand.
> Sure, you can put a liquid, hybrid. solid stage on a orbiter stage and make
> things easier but that won't be much help commercially.
No, as I've said before, I don't believe in manned solids, or solids
for any kind of routine launches (particularly of reusables).
> We're talking about BIG reductions in launch costs and, until you or someone
> else can show me a multi-stage vehicle that can deliver on that issue,
> you're just talking thru your hat.
I could just as easily ask you to show me a single stage vehicle that
delivers on that issue. There ARE NO cheap launchers, so in a sense
we are all talking through our hats. That doesn't mean we can't examine
potential cost reduction strategy and make reasonable guesses.
>> I'm getting really tired of this assumption that SSTO is the only
>>path to RLV and a fully commercial market.
> Like I said, show me the alternative.
If you insist that I point to existing hardware, of course I can't.
Neither can you.
Doug Hendrix
kin...@harvey.cyclic.com (Jim Kingdon) wrote:
>In-reply-to: nhen...@ren.com's message of 19 Dec 1995 00:45:21 GMT
>X-Newsreader: Gnus v5.0.12
>Status: N
>
>> I've been there and done that on multi-stage RLV's, in about
>> 1970-1971. If people gripe about the Shuttle, thank your stars that NASA
>> didn't build one of the Flyback boosters/Flyback Orbiters that were
>> considered. The problems were legion
>
>Well, would you care to summarize a few of the problems? References
>to published sources would also be appreciated (particularly sources
>which I could order a copy of, find in a library, or (better yet) read
>on the web).
>
>If by "multi-stage" one includes options like a low-delta-V "zero"
>stage, two (or more) identical stages, aerial propellant transfer,
>etc., there are a lot of ideas that look plausible on paper but
>haven't been tried in hardware.
>
My newsreader ate my eloquent response so this one will be shorter, I'm on
furlough and have a lot of things to do today ('tis the season to be jolly,
you know). No, I don't have anything but yellowing drawings in my archives.
Nasa archives could be researched I suspose. But, the problems are what you'd
expect: Ops, Integration, Flt. Dynamics and Loads, etc. I don't know of any
RLV multistage concept that eliminates all of them. Sure, some ideas may look
good on paper but the closer inspections will show the problems. Besides, do
any of these concepts really have advantage over a well tuned expendable?
You've got to go pretty far to compete against some of the expendables.
Really, the policy question becomes, Is it better to flight demo technology
that probably won't yeild a SSTO RLV or is it better to ground test that
technology and use the money saved to go after the technolgy that yeilds a
SSTO RLV? After all, we've incorporated lots of technlogy into launch vehicles
without flight demo's.
Incidently, you ducked my question as to what makes you think RLV is pretty
much on track ( your words, original post)
>(to Doug Hendrix: I tried to respond to your email, but my message
>bounced).
Sorry, I get Email all the time. Must have been a glitch.
Jim Kingdon
> reusable launch veicle and disposable engines.
I know people have looked at the reverse--a disposable launch vehicle
which jetisons a recoverable engine pod.
Disposable engines on a reusable vehicle is an interesting
concept--you'd presumably use some really simple ablatively cooled
engine. Now interesting does not necessarily equal promising--I am
not inclined to think that reusing engines is all that hard (the
RL-10, for example, on test stands and to a lesser extent on DC-X, has
demonstrated it can be used many times with minimal maintenance), and
that if you are going to dispose of the engines you might as well save
yourself the hassles of recovering the vehicle (downrange recovery
site, thermal protection system, etc.)--but who knows?
Doug Hendrix
>In article <4avs0r$2...@news.ro.com>, nhen...@ren.com (Doug Hendrix) writes:
>> And the consequence may well be that, in 1999, we wind up with no
>> commercial financial support for a commercial RLV. We may just be proving
>> technology for an improved multi-stage launch vehicle.
>
> Read my lips: RLV DOES NOT HAVE TO BE SSTO. Please stop confusing
>two separate issues. There is a lot of room for cost reduction and
>more routine operatoins even without SSTO.
>
READ MY LIPS: I've been there and done that on multi-stage RLV's, in about
1970-1971. If people gripe about the Shuttle, thank your stars that NASA
didn't build one of the Flyback boosters/Flyback Orbiters that were
considered. The problems were legion and guess what: WE HAVEN'T ADVANCED
ENOUGH IN THE LAST 25 YEARS TO MAKE THOSE PROBLEMS MUCH EASIER. Sure, you can
put a liquid, hybrid. solid stage on a orbiter stage and make things easier
but that won't be much help commercially. We're talking about BIG reductions
in launch costs and, until you or someone else can show me a multi-stage
vehicle that can deliver on that issue, you're just talking thru your hat.
> I'm getting really tired of this assumption that SSTO is the only
doyle@problem_with_inews_gateway_file
Has any body looked at the possibility of really cheap disposable
engines which are easy to install?
Jim Kingdon
> 1970-1971. If people gripe about the Shuttle, thank your stars that NASA
> didn't build one of the Flyback boosters/Flyback Orbiters that were
> considered. The problems were legion
Well, would you care to summarize a few of the problems? References
to published sources would also be appreciated (particularly sources
which I could order a copy of, find in a library, or (better yet) read
on the web).
If by "multi-stage" one includes options like a low-delta-V "zero"
stage, two (or more) identical stages, aerial propellant transfer,
etc., there are a lot of ideas that look plausible on paper but
haven't been tried in hardware.
(to Doug Hendrix: I tried to respond to your email, but my message
bounced).
'Larry' L Gales
>
> READ MY LIPS: I've been there and done that on multi-stage RLV's, in about
> 1970-1971. If people gripe about the Shuttle, thank your stars that NASA
> didn't build one of the Flyback boosters/Flyback Orbiters that were
> considered. The problems were legion and guess what: WE HAVEN'T ADVANCED
> ENOUGH IN THE LAST 25 YEARS TO MAKE THOSE PROBLEMS MUCH EASIER. Sure, you can
> put a liquid, hybrid. solid stage on a orbiter stage and make things easier
> but that won't be much help commercially. We're talking about BIG reductions
> in launch costs and, until you or someone else can show me a multi-stage
> vehicle that can deliver on that issue, you're just talking thru your hat.
>
[ man...@bnr.ca (Cathy Mancus) wrote:]
> > I'm getting really tired of this assumption that SSTO is the only
> >path to RLV and a fully commercial market.
> >
>
> Like I said, show me the alternative.
============================================================
Several months ago I posted a design for a fully reusable, 2-stage, VTVL,
base first re-entry vehicle using Russian NK-31 and Block D Kerosene/LOX
engines. The only "new" technology for this would be ajustable nozzle
skirts for altitude compensation. With a GLOW of about 350 tons
it could place 7-10 tons into LEO. This was a Kerosene/LOX version of
William Mook's LH2/LOX design.
(1) I don't think there is a rocket engineer in the world who would say
that we could not build such a vehicle today
(2) I don't think there is a rocket engineer who would disagree with the
statement that such a vehicle would be vastly simpler and less expensive
than the shuttle during all phases of its flight: stacking, fueling,
launch, flight profile, aerodynamics, staging, re-entry, landing, turn-around.
It features mission completion with one-engine out during all phases of the
flight, mission completion with multi-engine failure thru some phases of the
flight, and safe abort with multi-engine failure thru all flight phases.
As was mentioned in that post, the principle reason that stacking and staging
are currently expensive is because current vehicles (including most of the
stacking-staging elements of the shuttle) are *expendable* and so there is
no incentive to make those aspects cheaper -- stacking is simply that part
of building a vehicle that happens at the launch pad instead of at the
factory, but this should not be true for a reusable vehicle.
There are also other concepts, such as an NSSTO with a purely vertical
"zero-or-cheater" stage that are well within currently technology and could
bring about immense savings, as well as the "blackhorse" concept.
I fully agree with the statement made by Cathy Mancus above.
-- Larry Gales
Jim Kingdon
Clearly a big issue for multi-stage reusables. X-34 seems like a
plausible way to try to get some experience with these issues at an
affordable cost (reusable stage separation instead of pyros, etc.).
> Flt. Dynamics and Loads
As far as I know, this is primarily an issue for doing a return to
launch site maneuver. I am inclined to agree, but my conclusion is
just to go with downrange recovery.
> Besides, do any of these concepts really have advantage over a well
> tuned expendable?
OSC's willingness to put their own money into X-34 would tend to point
to "yes", but time will tell (provided X-34 really flies, of course).
> Really, the policy question becomes, Is it better to flight demo
> technology that probably won't yeild a SSTO RLV or is it better to
> ground test that technology and use the money saved to go after the
> technolgy that yeilds a SSTO RLV? . . .
> Incidently, you ducked my question as to what makes you think RLV is pretty
> much on track ( your words, original post)
It is on track (IMHO) because it is really demonstrating technology
(DC-XA, Russian engine firings, other engine tests, TPS tests,
etc.--see http://rlv.msfc.nasa.gov for details), not putting all its
eggs in the X-33 basket. If an X-33 flight vehicle (or any other
single item, like an all-new, very expensive, engine) seems to be in
danger of crowding out all the other stuff being done as part of the
program, I'd argue for canceling it, but I am not convinced this is
the case. And there does need to be some program component along the
lines of "just how light can we make a vehicle?" (aimed at
SSTO)--while there is a case (e.g. Big Dumb Boosters) for saving the
design and fabrication $$$ involved in trimming mass, I am more
sympathetic to the "trim mass whereever you can" school of
thought--and there needs to be a program exploring that.
RLV is a stronger program than *I* probably would have designed if I
had been in charge a year or so ago--I probably would have picked a
boring, straightforward "let's build DC-Y, and if we have trouble with
mass fraction or other issues, push harder" approach, which now
doesn't look as good to me as what they are actually doing.
Michael P. Walsh
>(1) I don't think there is a rocket engineer in the world who
(Was a comment on a resusable LOX-RP1 booster)
I think this is true, but to date it has not been done. I
believe this has been one of the relatively unmentioned good
points of the X-34 program. If they can demonstrate a
reliable and reusable propulsion stage I believe it will be a
modest but important step toward economical launch vehicles.
I am less certain about the economic/capability match of a large
Lox-RP1 two stage recoverable booster.
Doug Hendrix
> I think we have learned one or two things since 1971 (particularly in
>materials science).
>
Yes, but is it neccesary to flight demo those things? All I'm saying is if the
technolgy being flight demo'd really has a chance of leading to a breakthough
in launch costs and flight demo's really are neccesary to get investor
confidence to to point of making investments, then by all means, flight demo.
But, if the technology isn't good enough to make that breakthru, a flight demo
makes no sense. I contend that the present batch of technology available for
flight demo testing won't make the breakthrough. Come 2000, we'll still be out
of luck as far as cheap launchers are concerned. It's easy to locate the areas
that need new technolgy and propulsion is one of those areas.
<cut>
> I think you have a particular view of what
>your TSTO looks like, and are using it to block out alternatives.
>You simply can't rule out all large-cost-reduction TSTO RLV's with a
>sweep of your hand.
>
I haven't seen any alternatives that had enough meat on them to make them
believable. Take 'em to a preliminary design state and see if they still hang
together. Most concepts look good initially...mature them and then see if they
still look good.
>
> I could just as easily ask you to show me a single stage vehicle that
>delivers on that issue. There ARE NO cheap launchers, so in a sense
>we are all talking through our hats. That doesn't mean we can't examine
>potential cost reduction strategy and make reasonable guesses.
>
Absolutely correct! My point is, once again, does the current batch of
technolgy lead to a cheap launcher? If not, then why are we so hopped up to go
fight demo it? We need confidence that the technolgy being flight demo'd is
technolgy that leads to cheap launchers.
>>> I'm getting really tired of this assumption that SSTO is the only
>>>path to RLV and a fully commercial market.
>
>> Like I said, show me the alternative.
>
> If you insist that I point to existing hardware, of course I can't.
>Neither can you.
>
I don't insist on hardware, just a concept that is matured to a preliminary
design state with some analysis behind the weight statement (weight from
weight estimating routines don't count, they aren't accurate enough) and cost
analysis that an investor would believe.
Jeff Greason
In article <4b51v2$d...@news.ro.com>, nhen...@ren.com (Doug Hendrix) writes:
|> In article <4b40s1$m...@brtph500.bnr.ca>, man...@bnr.ca (Cathy Mancus) wrote:
|>
|> > Read my lips: RLV DOES NOT HAVE TO BE SSTO. Please stop confusing
|> >two separate issues. There is a lot of room for cost reduction and
|> >more routine operatoins even without SSTO.
|> >
|>
|> READ MY LIPS: I've been there and done that on multi-stage RLV's, in about
|> 1970-1971. If people gripe about the Shuttle, thank your stars that NASA
|> didn't build one of the Flyback boosters/Flyback Orbiters that were
|> considered. The problems were legion and guess what: WE HAVEN'T ADVANCED
|> ENOUGH IN THE LAST 25 YEARS TO MAKE THOSE PROBLEMS MUCH EASIER. Sure,
|> you can
|> put a liquid, hybrid. solid stage on a orbiter stage and make things easier
|> but that won't be much help commercially. We're talking about BIG reductions
|> in launch costs and, until you or someone else can show me a multi-stage
|> vehicle that can deliver on that issue, you're just talking thru your hat.
|>
|> > I'm getting really tired of this assumption that SSTO is the only
|> >path to RLV and a fully commercial market.
|> >
|>
|> Like I said, show me the alternative
Mass produced dumb boosters. Big Dumb Boosters. Aerial Reoxing (BlackHorse).
"Near-SSTO" with JATO assist. "Near-SSTO" with an exoatmospheric kick
stage.
I believe that SSTO can provide a significant cost reduction over
near-SSTO or dumb boosters. But it seems obvious that if X-33 were
to show we can make, say, 90% or orbital speed with a fully reusable
vehicle, turned around in days not months, with high operability, we'd
be *far* better off, and far closer to a low launch cost system.
You could take that and make a "Near-SSTO" right away. And you'd have
learned so much about operable engines and TPS that your next try at
SSTO might well suceed. Meantime, X-34 is trying to bring "staging"
out of the 1950's, and could be teaching us what we need to do 1.5STO
or 2STO "right".
And if none of these efforts suceed, studies from Truax on have shown
that expendables can be a *lot* cheaper than they are now -- so it's
silly to argue that it's SSTO or nothing.
The only "must have" about SSTO that I see is that X-33 "must" stay
focused on *trying* for SSTO -- otherwise we *will* wind up with
a ShuttleII + Flyback booster, and we won't learn a thing.
Disclaimer: While I am an Intel employee, all opinions expressed are my own,
and do not reflect the position of Intel, NETCOM, or Zippy the Pinhead.
============================================================================
Jeff Greason "We choose to go to the Moon in this decade,
<gre...@ptdcs2.intel.com> and do the other things, not because they
<gre...@ix.netcom.com> are easy, but because they are hard." -- JFK
Filip De Vos
: In article <4b51v2$d...@news.ro.com>, nhen...@ren.com (Doug Hendrix) writes:
: And if none of these efforts suceed, studies from Truax on have shown
: that expendables can be a *lot* cheaper than they are now -- so it's
: silly to argue that it's SSTO or nothing.
What is in fact the status of (the ideas of) Bob Truax? My only source
is Ed Regis' Great Mambo Chicken and the Transhuman Condition, and
of course the generic Big Dumb Booster idea turning up. I also recall
just after Challenger there was an article about an areospace-engineer
promoting the BDB idea in Newsweek.
And of course I'm awaiting col. Jack London's book!!
--
Filip De Vos I am just a simple home-boy, and take
no great interest in anything much
beyond the Magellanic Clouds.
FilipP...@rug.ac.be
fid...@eduserv.rug.ac.be Marshall T. Savage
Cathy Mancus
In article <4bcjjp$g...@ptdcs5.al.intel.com>, gre...@ptdcs2.intel.com (Jeff Greason) writes:
> The only "must have" about SSTO that I see is that X-33 "must" stay
> focused on *trying* for SSTO -- otherwise we *will* wind up with
> a ShuttleII + Flyback booster, and we won't learn a thing.
Absolutely true, Jeff. Don't mistake my interest in RLV TSTO approaches
for lack of support for SSTO X-vehicle testing.
Jim Kingdon
> is Ed Regis' Great Mambo Chicken and the Transhuman Condition, and
> of course the generic Big Dumb Booster idea turning up.
A few new boosters are getting low-level air force funding, and some
private funding too I think. See
<URL:http://www.earthlink.net/~microcosm/> and
<URL:http://www.isso.org/Industry/AeroAstro/AA-Projects.html#2.6>.
Both are in at least some ways "dumb" (although not "Big" in terms of
payload)--both are pressure-fed; PacAstro is only 2 stages to orbit
whereas microcosm uses a large number of identical stages.
Doug Hendrix
fid...@eduserv.rug.ac.be (Filip De Vos) wrote:
>Jeff Greason (gre...@ptdcs2.intel.com) wrote:
>
>: In article <4b51v2$d...@news.ro.com>, nhen...@ren.com (Doug Hendrix)
writes:
>
Be careful with your clips and snips. ole boy, I didn't write that which
follows. I catch enough flack for that which I do write.
>: And if none of these efforts suceed, studies from Truax on have shown
>: that expendables can be a *lot* cheaper than they are now -- so it's
>: silly to argue that it's SSTO or nothing.
>
>What is in fact the status of (the ideas of) Bob Truax? My only source
>is Ed Regis' Great Mambo Chicken and the Transhuman Condition, and
Doug Hendrix
gre...@ptdcs2.intel.com (Jeff Greason) wrote:
>In article <4b51v2$d...@news.ro.com>, nhen...@ren.com (Doug Hendrix) writes:
Clipped ---
>Sure, you can
>|> put a liquid, hybrid. solid stage on a orbiter stage and make things
easier
>|> but that won't be much help commercially. We're talking about BIG
reductions
>|> in launch costs and, until you or someone else can show me a multi-stage
>|> vehicle that can deliver on that issue, you're just talking thru your hat.
>|>
Cathy Wrote:
>|> > I'm getting really tired of this assumption that SSTO is the only
>|> >path to RLV and a fully commercial market.
>|> >
>|>
>|> Like I said, show me the alternative
>
>Mass produced dumb boosters. Big Dumb Boosters. Aerial Reoxing
(BlackHorse).
>"Near-SSTO" with JATO assist. "Near-SSTO" with an exoatmospheric kick
>stage.
>
Doesn't answer the question. Dunb Boosters won't give the order of magnitude
reduction in costs we're after. I don't know much about reoxing but it sounds
preliminary and fraught with problems that'll drive costs sky high. Near SSTO
stuff will be light weight payload delivery. That's fine if all you want to do
is service Earthlings with neater mobile phones, I'd like to see Earthling go
into real space endevours.
Michael P. Walsh
>>that NASA didn't build one of the Flyback boosters/Flyback
>Well, would you care to summarize a few of the problems?
>References to published sources would also be appreciated.
I did not originate and I don't have references but I did work on
a study of a 2 stage flyback booster at Lockheed in 1962-65.
The most serious problem was design of a fly-back orbital
upper-stage LO2-LH2 propellant tank integrated into a vehicle.
Then the state-of-the art heat shield was ablative coating. The
shuttle tiles were an advancement but the tank problem was
finessed with the throw-away tanks.
The main problem with the first stage was size and cost, as well
as sensitivity of the size of the first stage to any increases in
size and weight of the upper stage. This was resolved by the
switch to the SRB's. Staging of the nested vehicles was
condsidered a problem, but I did not hear anyone who thought it
could not be resolved.
I think recovery and reuse of full-scale propulsion systems which
include tanks is still a problem.
William H. Mook, Jr.
>
> In article <4b40s1$m...@brtph500.bnr.ca>, man...@bnr.ca (Cathy Mancus) wrote:
> >
> >path to RLV and a fully commercial market.
> >
>
Check out my GreenSpace(TM) TSTO-RLV concept at
http://s1.GANet.NET/~wm0/mtest0.htm
Its and unpiloted vehicle that separates outside the atmosphere with
near optimal stage fractions. It uses an SSME on the first stage and
four RL10s on the second stage. It executes a downrange recovery of
the first stage. Vertical landing of both stages is carried out
through a powered touchdown of the stages. It competes head to head
in throw weight with the Atlas vehicles. Its recurring costs are
about $9 million per launch but delivers launches worth $125 million.
Most of this $9 million figure goes for maintenance of the advanced
SSME built to meet the needs of this vehicle.
A fleet of three vehicles will deliver more launches than the entire
production history of the Atlas missile. It uses no really new or
advanced technology.
The profits earned by this vehicle will pay for research and development
of larger vehicles. Next generation vehicles will use the first stage
of the first generation vehicle as a second stage. The second generation
first stage will comprise five SSME and the resulting TSTO-RLV-G2 will
loft a total of 90,000 lb. to LEO. A three stage vehicle, consisting
of the the entire generation 1 vehicle along with a generation 2 first
stage will be capable of placing 9,500 lb on the lunar surface and
returning to Earth all vehicle components for reuse.
A third generation vehicle is possible building upon the strengths of
the two generations described. The third generation builds upon a
larger first stage. This larger first stage is propelled by 25 SSME
collected into an aerospike configuration. The second stage is the
second generation first stage propelled by five SSME. TSTO-RLV-G3 will
loft a total of 450,000 lb to LEO. A three stage vehicle, consisting of
the entire generation 2 vehicle along with a generation 3 first stage
will be capable of placing 47,500 lb on the lunar surface and returning
all vehicle components to Earth for reuse.
The last generation vehicle on our drawing boards consists of a fourth
generation first stage. This mammoth vehicle is propelled by 125 SSME
collected into two rings. 62 SSME on the inner ring, 63 SSME on the
outer ring. Forming a huge aerospike engine. The TSTO-RLV-G4 will
place 3 million lb to LEO and 250,000 lb on the lunar surface. It
will also project 50,000 lb. payloads to Mars.
What will the markets be for these vehicles?
G1 - 18,500 lb LEO - Commercial launch vehicle -
G2 - 90,000 lb LEO - Space station components - Return to Moon -
G3 - 450,000 lb LEO - Experimental Solar Power Satellites/Lunar Tourism -
G4 - 3,000,000 lb LEO - Commercial Solar Power Satellites/Lunar Development -
Mars Exploration, Asteroid Exploration
Beyond this development program I also propose the development of large
laser launchers. The profits from G2 will be sufficient to develop G3
as well as a small laser launcher. Laser launchers will permit large
numbers of small payloads to be orbited and sent to the moon in support
of operations at these places. Larger orbiting laser propulsion drivers
powered by the sun - based on orbiting solar power station technology,
will permit commercial travel throughout the solar system once sufficient
assets are in place.
William H. Mook, Jr.
Jim Kingdon
> G1 - 18,500 lb LEO
There is a particularly insidious tendency to think of "next
generation" as "larger". Ariane 5 has the potential to take Europe
out of the commercial launch market. The fact that OSC developed
Pegasus XL instead of sticking with Pegasus has been a disastrous
decision, and may very well give LLV enough time to catch up with
them.
A successful launcher will probably inspire a variety of derivatives,
but they won't all be larger (e.g. Delta II spawned Delta III, but it
also spawned Delta Lite; Atlas II* spawned Atlas 2AR which is similar
in size, etc.).
Doug Hendrix
"William H. Mook, Jr." <w...@mail.GANet.NET> wrote:
>Its and unpiloted vehicle that separates outside the atmosphere with
>near optimal stage fractions. It uses an SSME on the first stage and
>four RL10s on the second stage. It executes a downrange recovery of
>the first stage. Vertical landing of both stages is carried out
>through a powered touchdown of the stages. It competes head to head
>in throw weight with the Atlas vehicles. Its recurring costs are
>about $9 million per launch but delivers launches worth $125 million.
>Most of this $9 million figure goes for maintenance of the advanced
>SSME built to meet the needs of this vehicle.
>
I'm sorry but I don't see how any downrange recovery Vehicle can be operated
at $9M per launch. You're a brave soul to mention using SSME's around these
parts tho'. However, I will visit your page to read more.
Clipped ...
> G1 - 18,500 lb LEO - Commercial launch vehicle -
> G2 - 90,000 lb LEO - Space station components - Return to Moon -
> G3 - 450,000 lb LEO - Experimental Solar Power Satellites/Lunar Tourism -
> G4 - 3,000,000 lb LEO - Commercial Solar Power Satellites/Lunar Development
-
Your hearts in the right place. The heck with inward looking, let's go
somewhere off this world.
Michael Gallagher
>Its and unpiloted vehicle that separates outside the atmosphere with
>near optimal stage fractions. It uses an SSME on the first stage and
carried out
>through a powered touchdown of the stages ... It uses no really new or
>advanced technology ...
>
The SSMEs aren't new, but I wouldn't call them "not advanced." At the
very least, they're a finiky peace of machinery, requiring a decent
amount of mainteneance and testing. If some of the ALS engines had gone
into productions, with fewer welds and lower maintenance requirements,
you'd have a chance. But I don't see how the SSMEs will reduce your
costs --- unless you fly them twice and scrap 'em.
And then there's the vertical landing concept, which has barely been
touched on by DC-X and NEVER used in any launch vehicle! Ok, I'll allow
Surveyor, Viking, and the Lunar Modules, but those are vehicles that
lnaded on OTHER PLANETS. Verticla landing has never been used to recover
launch vehicles. You're making your job easier by doing this in two
stages instead of one, but the fact remains both stages will have to
carry extra fuel for landing. Tha'ts not even remortely an "off the
shelf" technique. (And also why horixontal landings are nicer --- no
feule required beyond the needs of your retros.)
Around the same paragraphs, you make the following claims:
> ... Its recurring costs are
>about $9 million per launch but delivers launches worth $125 million.
>Most of this $9 million figure goes for maintenance of the advanced
>SSME built to meet the needs of this vehicle.
>
Are you serious? Does anybody know what NASA spends on maintaning the
SSMEs? Because it may be that in reality, it could cost a bit more!
>A fleet of three vehicles will deliver more launches than the entire
>production history of the Atlas missile ...
The Atlas missile has been in production for 30-40 years, and used as a
launch vehicle since the early '60s. That's a LOT of launches. How long
would it take your green booster to catch up to it? If the anser is "one
year," your in the same club as the people who made extravegant claims on
the shuttle's performance. It's not that you don't have a good idea.
But when you get into the real world specifics of actually operating the
thing, you're going to find things a bit slower and more costly than you
hoped.
"It only takes ten seconds to describe it, and I'll do it for you in a
minute" -- David Gunson
Michael J. Gallagher aka mmf...@prodigy.com
Michael Gallagher
>
>A few new boosters are getting low-level air force funding, and some
>private funding too I think. See
><URL:http://www.earthlink.net/~microcosm/> and
><URL:http://www.isso.org/Industry/AeroAstro/AA-Projects.html#2.6>.
>Both are in at least some ways "dumb" (although not "Big" in terms of
>payload)--both are pressure-fed; PacAstro is only 2 stages to orbit
>whereas microcosm uses a large number of identical stages.
I peaked at both web pages, and I couldn't help that both providers were
making claims about the costs and launch rates of their vehicles that
sound a lot like the claims made for the shuttle. And that makes me a
bit suspicious.
It could be that a common failing of launch vehicle designers --- and
I'll put the shuttle's designers in here --- is they neglect to look at
the real world reuirements of operating and maintaning the thing. And
that makes things a bit slower and more expensive than they thought. Ie,
if you just look at hom much new hardware is made for each shuttle flight
--- an ET and maybe an SRB --- it comes in on the cheap, in all
probability. But figure in the requirements of prerrping it for flight
and refurbishing it afterwards, and your savings go out the window.
Jim Kingdon
> making claims about the costs and launch rates of their vehicles that
> sound a lot like the claims made for the shuttle.
One claim that Microcosm makes which is very un-shuttle-like is that
their system would be cheap at low launch rates. No big traffic
models required (so they say anyway).
> It could be that a common failing of launch vehicle designers --- and
> I'll put the shuttle's designers in here --- is they neglect to look at
> the real world reuirements of operating and maintaning the thing.
Uh, Microcosm and PacAstro are both expendables. So refurbishing it
afterwards is not an issue.
Microcosm specifically mentions operability--they do not require a
launch tower (because their vehicle is wide and fat and has all its
umbilicals connected at the bottom).
Microcosm also has very specific, concrete goals about operations (how
many hours it takes to integrate a payload, only as much weather
delays as an airliner, etc.). There aren't enough details there to
say how much they have traced these requirements down to specific
design features, but they certainly *are* thinking about the issues.
George Herbert
>Cathy Wrote:
>>|> Like I said, show me the alternative
>
>Doesn't answer the question. Dunb Boosters won't give the order of magnitude
Won't? Umm, since when is $250-600/lb not an order of magnitude reduction?
Everyone who's looked at the problem seriously thinks you can do somewhere
in that range with BDBs, the somewhere depending on assumptions on technology,
volume, and how smart your design is in optimizing for price not performance.
Go take a look at Microcosm's Scorpius launcher some time. They almost have
the right idea (I'm nitpicking... they basically are doing everything right,
though I would go for single large engines instead of clustering small ones
like they are... but that keeps their engine development costs low.
And they've already built prototype engines for under $10,000 each.)
BDB may be eclipsed by SSTO, but if SSTO is harder than we think or
if the government bails out on funding its development, BDB's will be
the path to open up large enough markets at low price, enabling the
purely commercial SSTO development to proceed. This is not speculation.
It *will* happen. There's too much money in it for someone not to
make a BDB work. Look for Microcosm to be there flying things in the
early years of the 21st century. I may get some of my stuff off my
design board and join them, if I lose enough sanity to start my own
company for real instead of occational consulting work ;-)
-george william herbert
Retro Aerospace
gher...@crl.com
George Herbert
>[...]
>I'm sorry but I don't see how any downrange recovery Vehicle can be operated
>at $9M per launch. You're a brave soul to mention using SSME's around these
>parts tho'. However, I will visit your page to read more.
What? $9M/launch is way too high. You can buy a whole oil-platform
supply ship for $9m, and with about 10 crew (well, maybe 15) recover anything
from any ocean up to shuttle booster sized objects. 15 seamen is going to
be about $750,000 to $1m/year. Fuel oil is cheap, you can probably run
the thing for $100k/month for accumulated fuel, maintenance, and berth
fees etc.
Michael Gallagher
>
>> It could be that a common failing of launch vehicle designers --- and
>> I'll put the shuttle's designers in here --- is they neglect to look
at
>> the real world reuirements of operating and maintaning the thing.
>
>Uh, Microcosm and PacAstro are both expendables. So refurbishing it
>afterwards is not an issue.
>
But refurbishing is an issue on the shuttle, as well as for other schemes
involving resusable launchers, so that's why I stuck it in.
>Microcosm specifically mentions operability--they do not require a
>launch tower (because their vehicle is wide and fat and has all its
>umbilicals connected at the bottom).
>
>Microcosm also has very specific, concrete goals about operations (how
>many hours it takes to integrate a payload, only as much weather
>delays as an airliner, etc.). There aren't enough details there to
>say how much they have traced these requirements down to specific
>design features, but they certainly *are* thinking about the issues.
That's the thing --- if you just look at the design features, their goals
seem easy to reach. But when you look at what's actually involved in
building the hardware, prepping it and the payload for flight, their
goals may become a bit harder to reach than they think they are.
I'm definitely looking forward to the day when wwe do have "airline-like"
operations from Earth to LEO for both manned and unmanned vehicles. But
I am not sure we're going to get there in one fell swoop, no matter how
much one or two companies want to get there. It will require a lot of
different developments and the time to scale things up enough. That's
not going to happen overnight.
William H. Mook, Jr.
>
> > Next generation vehicles
> > G1 - 18,500 lb LEO
>
> generation" as "larger". Ariane 5 has the potential to take Europe
> out of the commercial launch market. The fact that OSC developed
> Pegasus XL instead of sticking with Pegasus has been a disastrous
> decision, and may very well give LLV enough time to catch up with
> them.
>
> A successful launcher will probably inspire a variety of derivatives,
> but they won't all be larger (e.g. Delta II spawned Delta III, but it
> also spawned Delta Lite; Atlas II* spawned Atlas 2AR which is similar
> in size, etc.).
Well Jim, this all depends on your vision of the future. If you
believe the future of space travel merely entails continued support
for communications satellites then a strong argument can be made for
fewer and smaller launch vehicles in the future. If on the other
hand you believe the future of space travel entails an expanding
industrial capacity then you have a need for larger and more numerous
launch vehicles. In either case if you support one vision or the
other, you must be prepared to define the new markets involved.
I propose there is a "Mook Curve" similar to Moore's curve for
micro-electronics. As you build larger spacecraft the cost per
pound is reduced. The growth curve envisioned for the GreenSpace
program is set by the ratio of the first and second stages. We
end up with a vee star of about 4.9 km/sec per stage. This is
sufficient to orbit payloads with two stages, or send payloads
to the moon with three stages, all without loss of vehicle components.
We also hope to improve the longevity of each launch vehicle with
each succeeding generation. So we hope to benefit in several ways.
Veh. Direct Costs Payload to LEO Cost/lb.
------------------------------------------------------------
G1 $9 million per launch 18,500 lb/launch $486.48/lb
G2 $18 million per launch 90,000 lb/launch $200.00/lb
G3 $36 million per launch 450,000 lb/launch $80.00/lb
G4 $72 million per launch 3,000,000 lb/launch $24.00/lb
------------------------------------------------------------
Of course, we'll start with G1 at about $7,500/lb and drop about
a third with each generation. This will provide profits sufficient
to attract and expand the capital assets to sustain the development
of the markets outlined.
Veh. Selling price /lb. and /launch Total Capacity
-----------------------------------------------------------
G1 $7,500/lb. $138,750,000 per launch. 450 launches
G2 $2,500/lb. $225,000,000 per launch. 1,350 launches
G3 $833/lb. $375,000,000 per launch. 4,050 launches
G4 $277/lb. $833,000,000 per launch 12,150 launches
-----------------------------------------------------------
William H. Mook, Jr.
>
> In article <30DBBD...@mail.GANet.NET>,
> "William H. Mook, Jr." <w...@mail.GANet.NET> wrote:
>
> >Its and unpiloted vehicle that separates outside the atmosphere with
> >near optimal stage fractions. It uses an SSME on the first stage and
> >through a powered touchdown of the stages. It competes head to head
> >about $9 million per launch but delivers launches worth $125 million.
> >Most of this $9 million figure goes for maintenance of the advanced
> >SSME built to meet the needs of this vehicle.
> >
>
> at $9M per launch. You're a brave soul to mention using SSME's around these
> parts tho'. However, I will visit your page to read more.
>
Well Doug, some folks think that $9 million recurring costs for a reusable
vehicle is outlandishly high. But we've come from first principles and
looked at the cost of operating the Shuttle and other vehicles. This is
a price we know we can beat, depending upon the launch schedule.
According to recent communique's we've had with NASA HQ, NASA won't have
any SSME's available for this project. So, we'll be buying new. This has
the disadvantage of pushing back the project while production is put underway.
It has the advantage of freeing us from the legacies of the past. Our SSMEs
will have simple improvements made to them. Each succeeding generation of
engines (we're buying a lot you can see) will accumulate improvements while
the folks who build them have an opportunity to perfect their craft.
The insurance folks like the SSME because it has such a long and illustrious
track record. Despite over 200 firings of 5 minutes each no failures of SSME
has ever occurred. Our engines on G1 will fire about 2.7 minutes each. So,
over the course of the entire history of the entire fleet, our SSMEs will
accumulate only 40% of the experience of the Shuttle fleet to date.
Of course we'll push that waaay beyond the Shuttle when we build G2 and
beyond!
> Clipped ...
>
> > G1 - 18,500 lb LEO - Commercial launch vehicle -
> > G2 - 90,000 lb LEO - Space station components - Return to Moon -
> > G3 - 450,000 lb LEO - Experimental Solar Power Satellites/Lunar Tourism -
> > G4 - 3,000,000 lb LEO - Commercial Solar Power Satellites/Lunar Development
> -
>
> Your hearts in the right place. The heck with inward looking, let's go
> somewhere off this world.
Precisely. If you look at the future of telecom we'll have to lower prices
just to compete against optical fiber and technologies that compete with
satellite based assets. If we do nothing to develop new space based assets
which launch vehicles are needed to support, we may look back on THIS time
as the golden age of opportunity for space travel. I know it doesn't seem
like it, but back in 1965 it seemed like the golden age of manned spacetravel
was ahead of us. In 1975 it was behind us.
Any new business requires leadership.
William H. Mook, Jr.
> >
> >near optimal stage fractions. It uses an SSME on the first stage and
> carried out
> >through a powered touchdown of the stages ... It uses no really new or
> >advanced technology ...
> >
> The SSMEs aren't new, but I wouldn't call them "not advanced." At the
> very least, they're a finiky peace of machinery, requiring a decent
> amount of mainteneance and testing. If some of the ALS engines had gone
> into productions, with fewer welds and lower maintenance requirements,
> you'd have a chance. But I don't see how the SSMEs will reduce your
> costs --- unless you fly them twice and scrap 'em.
Well, we're buying brand new SSMEs. They're actually SSME derivative rockets
pulling from the STME concepts also developed by Rockwell. We will be flying
them 50 to 60 times per engine. So we'll need three engines per vehicle over
the lifespan of the first generation vehicle. This will be improved over time.
> And then there's the vertical landing concept, which has barely been
> touched on by DC-X and NEVER used in any launch vehicle! Ok, I'll allow
> Surveyor, Viking, and the Lunar Modules, but those are vehicles that
> lnaded on OTHER PLANETS.
Its harder to do something on other planets than on the Earth.
>Verticla landing has never been used to recover
> launch vehicles.
Russians use small solids to land capsules on Earth all the time.
> You're making your job easier by doing this in two
> stages instead of one, but the fact remains both stages will have to
> carry extra fuel for landing.
The areal loading of a empty launch vehicle is far less than the areal loading
of an empty space shuttle, even with all its wings. So, the terminal velocity
is a little below sound speed for both stages once they complete reentry.
> Tha'ts not even remortely an "off the
> shelf" technique. (And also why horixontal landings are nicer --- no
> feule required beyond the needs of your retros.)
Well, we looked at parachute recovery, winged recovery, and powered recovery.
For an empty launch vehicle powered recovery was superior for a variety of
reasons. Consider that the exhaust velocity of our recovery rockets on the
first stage is about 4,200 m/sec and the vehicle has to be brought through a
delta vee of 340 m/sec. So, the propellant needed is about 8.4% of the entire
weight of the EMPTY stage. This is far less than strapping on a pair of wings
to fly the thing home. The control algorithm for a ballistic closure to a
point is well worked out. In fact we can use existing guidance and control
hardware and software almost without changes. Except instead of blowing up
at your target, you fire your engines! :)
> Around the same paragraphs, you make the following claims:
>
> > ... Its recurring costs are
> >about $9 million per launch but delivers launches worth $125 million.
> >Most of this $9 million figure goes for maintenance of the advanced
> >SSME built to meet the needs of this vehicle.
> >
> Are you serious? Does anybody know what NASA spends on maintaning the
> SSMEs? Because it may be that in reality, it could cost a bit more!
Well, let's see, we're spending $85 million for each SSME we acquire (not
reflected in these costs) and with 60 flights per engine another $200 million
over the life of the engine. Some say that's too damn much. But that's what
it costs as far as we can tell.
> >A fleet of three vehicles will deliver more launches than the entire
> >production history of the Atlas missile ...
>
> The Atlas missile has been in production for 30-40 years, and used as a
> launch vehicle since the early '60s. That's a LOT of launches. How long
> would it take your green booster to catch up to it?
I believe the Atlas has sustained about 200 to 300 launches, I have the exact
number in our market analysis. Our fleet of three vehicles will sustain a total
of 300 to 450 launches. We plan to fly off this inventory at a rate of 15 to 30
flights per year. So, it might take 15 to 30 years to match the Atlas. But I
hope by that time G1 is viewed as we view B52 or B727 today. Of course what
actually happens depends on aggregate market demand. But even in the most
optimistic scenario (multiple constellations) it would be 6 years.
Henry Spencer
>...[vertical landing] Tha'ts not even remortely an "off the
>feule required beyond the needs of your retros.)
The weight of fuel needed for vertical landing is less than the weight of
the wings, control surfaces, etc. needed for horizontal landing. Horizontal
landing is "nice" only because it is familiar; in many ways it's an inferior
method, historically necessary because aircraft engines were so feeble. The
thrust:weight ratio of rocket engines is high enough that the idea deserves
to be taken seriously.
--
Look, look, see Windows 95. Buy, lemmings, buy! | Henry Spencer
Pay no attention to that cliff ahead... | he...@zoo.toronto.edu
Henry Spencer
>I peaked at both web pages, and I couldn't help that both providers were
>making claims about the costs and launch rates of their vehicles that
>bit suspicious.
Why? The reason why those claims look similar is simple: they are the
*right* *objectives*. A system which did *not* make such claims would
not be worth pursuing.
>It could be that a common failing of launch vehicle designers --- and
>I'll put the shuttle's designers in here --- is they neglect to look at
>the real world reuirements of operating and maintaning the thing. And
>that makes things a bit slower and more expensive than they thought...
Of course, there's real world and then there's NASA :-). Compare the
requirements of operating and maintaining the shuttle to those of
operating and maintaining DC-X. Sure, the shuttle is a bigger and
more complex vehicle which meets more demanding specs... but it's not
*a thousand times* bigger and more demanding, which is roughly the
ratio of the crew sizes. There's still something wrong there.
Henry Spencer
>>|> > I'm getting really tired of this assumption that SSTO is the only
>>|> >path to RLV and a fully commercial market.
>>"Near-SSTO" with JATO assist. "Near-SSTO" with an exoatmospheric kick stage.
>
Why not? Aerospace hardware costs are much more a function of parts count
than of size; making things big and simple and dumb *is* a promising idea.
Many of the people who have investigated the notion say that it does have
the potential for that order of magnitude. (Incidentally, some of us are
after multiple orders of magnitude, but that's another issue.)
>I don't know much about reoxing but it sounds
>preliminary and fraught with problems that'll drive costs sky high.
Why? The USAF does flight refuelling every day, quite routinely, at modest
cost. There's no great mystery to it; "this isn't rocket science" :-).
>Near SSTO stuff will be light weight payload delivery.
Why? The JATO-assist schemes take the full vehicle into orbit. The
kick-stage schemes don't, but there's no reason why the payload has
to be small. (American Airlines doesn't bring the whole aircraft to
the door of your destination either.)
RHA
The russians also have a proven technology for dropping fifty ton battle
tanks by parachute with braking rockets the last few feet.
--
rha
Greason
<he...@zoo.toronto.edu> writes:
>
>In article <4bhuda$1b...@usenetw1.news.prodigy.com> MMF...@prodigy.com
(Michael Gallagher) writes:
>>...[vertical landing] Tha'ts not even remortely an "off the
>>shelf" technique. (And also why horixontal landings are nicer --- no
>>feule required beyond the needs of your retros.)
>
>The weight of fuel needed for vertical landing is less than the weight
>of the wings, control surfaces, etc. needed for horizontal landing.
>Horizontal landing is "nice" only because it is familiar; in many ways
>it's an inferior method, historically necessary because aircraft
>engines were so feeble. The thrust:weight ratio of rocket engines is
>high enough that the idea deserves to be taken seriously.
Henry, while I'm all in favor of developing vertical landing, I think
you're overstating the case here. Some fairly good numbers were posted
during the thread "The palpable superiority of horizontal landing",
that seemed to show pretty clearly that the weight penalty for an
*unpowered* horizontal landing was slightly less than that for a
*powered* vertical landing.
Certainly, vertical landing *is* "off the shelf" -- Harriers do it all
the time. It looks to me as if the vertical/horizontal landing choice
is close enough that it depends on what your vehicle has anyway. If
you already have wings (for air launch, or aerial reoxing), you should
land horizontally. If you already have enough rocket engine to support
vertical takeoff, you should land vertically. And if you want your
launch costs to be extremely high, you should do VTHL, and restrict
yourself to launching from the Cape :-).
--
Disclaimer: All opinions expressed are my own, and do not reflect
the position of Intel, NETCOM, or Zippy the Pinhead.
====================================================================
Jeffrey K. Greason "We choose to go to the moon ... and do
<gre...@ptdcs2.intel.com> the other things, not because they are
<gre...@ix.netcom.com> easy, but because they are hard" -- JFK
Michael Gallagher
>
>Michael Gallagher wrote:
>>
>> And then there's the vertical landing concept, which has barely been
>> touched on by DC-X and NEVER used in any launch vehicle! Ok, I'll
allow
>> Surveyor, Viking, and the Lunar Modules, but those are vehicles that
>> lnaded on OTHER PLANETS.
>
>Its harder to do something on other planets than on the Earth.
>
in landing spacecraft on other planets BUT ....
>>Vertical landing has never been used to recover
>> launch vehicles.
>
>Russians use small solids to land capsules on Earth all the time.
>
launched by an ELV and now descending on a parachute is not the same as
putting extra fuel on a booster and then having it land tail-first under
power from its own engines. As I said, vertical landing has yet to be
proven for recovering launch vehicle stages, and you have to test it and
prove it before you can use it. And that's going to take years and money.
> ... We plan to fly off this inventory at a rate of 15 to 30
>flights per year ...
Evenutally. But the early years will be involved with design and testing,
particularly wrt vertical landing.
> ... So, it might take 15 to 30 years to match the Atlas ...
Probably a little longer. I'm not AGAINST waht you want to do; I just
want to point out that it's easier said than done.
Michael Gallagher
>
>In article <4bhun1$18...@usenetw1.news.prodigy.com> MMF...@prodigy.com
(Michael Gallagher) writes:
>>I peaked at both web pages, and I couldn't help that both providers
were
>>making claims about the costs and launch rates of their vehicles that
>>sound a lot like the claims made for the shuttle. And that makes me a
>>bit suspicious.
>
>Why? The reason why those claims look similar is simple: they are the
>*right* *objectives*. A system which did *not* make such claims would
>not be worth pursuing.
>
But can they live up to the claims when it comes time to buid and operate
the vehicles in question? THAT'S what I'm wondering about!
>Compare the
>requirements of operating and maintaining the shuttle to those of
>operating and maintaining DC-X. Sure, the shuttle is a bigger and
>more complex vehicle which meets more demanding specs... but it's not
>*a thousand times* bigger and more demanding, which is roughly the
>ratio of the crew sizes.
>--
But DC-X is not an operational launch vehicle that flies into orbit,
delivers payloads, and then comes back. A better comparison would be
between the shuttle and a man-rated variant of the X-33. And THEN you
see how "demanding" things are.
Henry Spencer
>Microcosm specifically mentions operability--they do not require a
>launch tower (because their vehicle is wide and fat and has all its
>umbilicals connected at the bottom).
Actually, Proton doesn't use a tower either. (Yes, it has plumbing up the
side of the lower stages for fuelling the upper stages.) The towers used
at launch (as opposed to some of the ones used for preparations) do not
contribute significant mechanical strength to existing vehicles; they're
there solely to hold electrical connections, plumbing, and swarms of guys
with clipboards.
Quite a few of the new launch outfits have noticed that towers are of very
limited utility, especially if you consider the guys with clipboards to
be liabilities rather than assets. Taurus doesn't use a tower, and I don't
think LLV does either.
Michael Gallagher
>
>In article <m2n38jh...@harvey.cyclic.com> kin...@harvey.cyclic.com
(Jim Kingdon) writes:
>>Microcosm specifically mentions operability--they do not require a
>>launch tower (because their vehicle is wide and fat and has all its
>>umbilicals connected at the bottom).
>
of very
>limited utility ... Taurus doesn't use a tower, and I don't
>think LLV does either.
>--
REQUIRES towers for fueling. Furthermore, since Taurus is designed to be
launched from a site offering no more than a concrete slab, they errect a
temporary scaffolding as they assemble the rocket, and take it down
before launch. Adn even then, there's some srt of unblilcle thing
attached to the rocket that falls away at ignition, a la Redstone (I just
don't know what it's called). And the Redstones had a tower that they
rolled away before launch.
I see your point, but you're using bad examples.
Henry Spencer
>>>...claims about the costs and launch rates of their vehicles that
>>>sound a lot like the claims made for the shuttle...
>>Why? The reason why those claims look similar is simple: they are the
>
>But can they live up to the claims when it comes time to buid and operate
>the vehicles in question? THAT'S what I'm wondering about!
That is indeed the question. But the fact that the shuttle made similar
claims, and then failed to live up to them, should not be considered an
indication that the new systems can't live up to them either. We have,
one hopes, learned something from the shuttle experience.
>>Compare the
>>requirements of operating and maintaining the shuttle to those of
>>operating and maintaining DC-X. Sure, the shuttle is a bigger and
>>more complex vehicle which meets more demanding specs... but it's not
>>*a thousand times* bigger and more demanding...
>
>But DC-X is not an operational launch vehicle...
Please read what I wrote! Of course it's not. I said that. The X-33
will need lighter structure and reusable thermal protection, and it will
be bigger, which will increase the maintenance load. The point is that
the disparity in ground crews seems much too large even so. A factor of
ten, okay. A factor of a hundred... well, maybe. But a factor of a
*thousand*? That's too much.
William H. Mook, Jr.
>
> "William H. Mook, Jr." <w...@mail.GANet.NET> wrote:
> >
> >Michael Gallagher wrote:
> >>
> >> And then there's the vertical landing concept, which has barely been
> >> touched on by DC-X and NEVER used in any launch vehicle! Ok, I'll
> allow
> >> Surveyor, Viking, and the Lunar Modules, but those are vehicles that
> >> lnaded on OTHER PLANETS.
> >
> >Its harder to do something on other planets than on the Earth.
> >
> I brought it up because yes, vertical landing had been used before, but
> in landing spacecraft on other planets BUT ....
> >>Vertical landing has never been used to recover
> >> launch vehicles.
> >
> >Russians use small solids to land capsules on Earth all the time.
> >
> Firing a solid booster to soften the landing of a capsule that had been
> launched by an ELV and now descending on a parachute is not the same as
> putting extra fuel on a booster and then having it land tail-first under
> power from its own engines. As I said, vertical landing has yet to be
> proven for recovering launch vehicle stages, and you have to test it and
> prove it before you can use it. And that's going to take years and money.
>
Well, I guess one can't argue with that, but how many years, how much money?
Here's how recovery will proceed.
(1) Get GPS and inerital guidance fix before re-entry. Ballistic
adjustments to Hohmann aerocapture maneuver through small
burns using ACS.
(2) Use strakes to fly at angle of attack, maintaining lift through
the upper atmosphere. Areal loading is light so we must
maintain altitude while losing kinetic energy. For the first
stage we end up 990 miles downrange at about 80,000 ft altitude
going straight down about Mach 0.7
(3) Use strakes to maneuver above the landing threshold. CL/CD=1.4
which fixes the size of the base of a cone whose apex is at
80,000 ft. We use LASER tracking terminal guidance to bring
the spacecraft to within a few inches of where its desired.
(4) Directly above the landing point, descending at about 0.7 Mach
the engines fire at about 6,600 ft altitude and decelerate
the vehicle to zero velocity at zero altitude within 20
seconds. As the velocity drops below the effective speed of
the aerodynamic controls the vehicle switches over automatically
to ACS assisted operation, thus postive control is maintained
throughout the burn.
Step #1 can be tested with suborbital entries of similar speed on test
rockets. Its basically a precision burn on a suborbital sounding
rocket. Step #2 is developed on CFD computing platforms, then put
through wind tunnel tests, then you fire shapes in sounding rockets.
Then you fire test articles to the speeds and altitudes needed. Step #3
is accomplished through the drop testing payloads from aircraft and
later firing these payloads on sounding rockets. Still later firing
a live rocket through the required path. Step #4 can be tested using
drop towers, drop tests from aircraft, drop tests from sounding rockets,
and finally tests using a completed rocket.
This whole program will cost less than $300 million and take less than
18 months according to our figures. Most of the work can be carried out
with models at White Sands NM and later with custom built test articles
again at White Sands. We'll also orbit each RLV and bring it back by
way of flight testing. The whole program should take about 48 months
and cost $1,400 million to complete. We'll end up with 3 TSTO-RLVs
each capable of sustaining 150 flights. This has a total market value
of $45 billion. Discounted for the 30 year time period it will take
to fly off this fleet, NPV at start of operations would be around $19
billion. That's about 91.9% ROI... even if it takes 30 years to fly
off the fleet's capacity.
Some other interesting points about RLVs: (1) They'll have test flown
prior to accepting their first paying customer. This means they're
reliable in ways not possible with ELV. (2) They're in inventory, so
there's a very short wait time between order and flight
> > ... We plan to fly off this inventory at a rate of 15 to 30
> >flights per year ...
>
> Evenutally. But the early years will be involved with design and testing,
> particularly wrt vertical landing.
Like I said, 18 months for that aspect of the design process. 48 months from
dropping the first dollar to the first paying flights. There will be 9 test
flights early on.
> > ... So, it might take 15 to 30 years to match the Atlas ...
>
> Probably a little longer. I'm not AGAINST waht you want to do; I just
> want to point out that it's easier said than done.
Maybe.
myc...@clark.net
Michael Gallagher <MMF...@prodigy.com> wrote:
>The disparity owes itself in part to the fact that the shuttle's
>designers decided from the beginning to (re)use LC 39 for shuttle
>launches. If you will, they were thinking in terms of a Saturn V with
>wings. This kind of made sesne to justify the continued expense of
>maintaning LC 39. If they'd started from LC 34, things might have been
>different.
>
>And the question isn't the ground crew requirements of even the X-33 ---
>which hopefully will be smaller than the shuttle's --- but with the
>ground crew requirements of an operational (man-rated?) RLV that (a) is
>derived from X-33 and (b) succeeds the shuttle. That's the comaprison
>that, to my mind, is the most valid. Otherwise, you're comparing apples
>and oranges.
Don't be surprised if the actual use of a vertical launch/landing
SSTO by NASA involves landing it on pad 39A or B, bringing out the
crawler to return the launch/landing platform to the VAB for the
vehicle to be refurbished and then rolling it out again, after it has
been rebuilt. This would be done in the name of economy, since it
would prevent a new facility having to be built.
The disassembly, tolerance check on all components and reassembly
between each flight would be done in the name of flight safety.
--
Michael T. Bevan WA3NAK ; B.S. Phys. ; CFI CFII MEI (pick a set as relevant)
Primary addr: myc...@clark.net Others: 72245,1432 WA3...@W3ZH.MD.USA.NA
William H. Mook, Jr.
burnside
: In article <4bhuda$1b...@usenetw1.news.prodigy.com> MMF...@prodigy.com (Michael Gallagher) writes:
: >...[vertical landing] Tha'ts not even remortely an "off the
: >shelf" technique. (And also why horixontal landings are nicer --- no
: >feule required beyond the needs of your retros.)
: The weight of fuel needed for vertical landing is less than the weight of
: the wings, control surfaces, etc. needed for horizontal landing. Horizontal
: landing is "nice" only because it is familiar; in many ways it's an inferior
: method, historically necessary because aircraft engines were so feeble. The
: thrust:weight ratio of rocket engines is high enough that the idea deserves
: to be taken seriously.
: --
: Look, look, see Windows 95. Buy, lemmings, buy! | Henry Spencer
: Pay no attention to that cliff ahead... | he...@zoo.toronto.edu
I dispute the assertion that the weight of the fuel needed for
vertical landing (assuming by 'fuel' you actually mean propellant)
is less than the horizontal landing hardware. Most studies that
examine horizontal landers wind up with 5-6% of the landed mass
allotted to HL-specific systems. I have never seen a vertical
lander with less than ten percent of its mass at landing set aside
for landing propellant. (Think of it as thirty seconds).
Mitchell Burnside Clapp
Michael Gallagher
>
>In article <4blc82$f...@usenetw1.news.prodigy.com> MMF...@prodigy.com
(Michael Gallagher) writes:
>>>
>>>Compare the
>>>requirements of operating and maintaining the shuttle to those of
>>>operating and maintaining DC-X. Sure, the shuttle is a bigger and
>>>more complex vehicle which meets more demanding specs... but it's not
>>>*a thousand times* bigger and more demanding...
>>
>>But DC-X is not an operational launch vehicle...
>
I did.
> ... Of course it's not ...
I know.
> ... I said that ...
You didn't. Nor did you mention the X-33 in your post. But anyway ...
> ... The point is that
>the disparity in ground crews seems much too large even so. A factor
of
>ten, okay. A factor of a hundred... well, maybe. But a factor of a
>*thousand*? That's too much.
>--
The disparity owes itself in part to the fact that the shuttle's
designers decided from the beginning to (re)use LC 39 for shuttle
launches. If you will, they were thinking in terms of a Saturn V with
wings. This kind of made sesne to justify the continued expense of
maintaning LC 39. If they'd started from LC 34, things might have been
different.
And the question isn't the ground crew requirements of even the X-33 ---
which hopefully will be smaller than the shuttle's --- but with the
ground crew requirements of an operational (man-rated?) RLV that (a) is
derived from X-33 and (b) succeeds the shuttle. That's the comaprison
that, to my mind, is the most valid. Otherwise, you're comparing apples
and oranges.
"It only takes ten seconds to describe it, and I'll do it for you in a
Doug Hendrix
Henry Spencer <he...@zoo.toronto.edu> wrote:
>In article <4bert4$e...@news.ro.com> nhen...@ren.com (Doug Hendrix) writes:
>>>|> > I'm getting really tired of this assumption that SSTO is the only
>>>|> >path to RLV and a fully commercial market.
>>>|> Like I said, show me the alternative
>>>Mass produced dumb boosters. Big Dumb Boosters. Aerial Reoxing
(BlackHorse).
>>>"Near-SSTO" with JATO assist. "Near-SSTO" with an exoatmospheric kick
stage.
>>
>>Doesn't answer the question. Dunb Boosters won't give the order of magnitude
>>reduction in costs we're after...
>
>Why not? Aerospace hardware costs are much more a function of parts count
>than of size; making things big and simple and dumb *is* a promising idea.
>Many of the people who have investigated the notion say that it does have
>the potential for that order of magnitude. (Incidentally, some of us are
>after multiple orders of magnitude, but that's another issue.)
>
If we can PROVE an order of magnitude cost reduction right now, we'd be smart
to put SSTO on back burner and go do BDB. I don't think we can prove it.
>>I don't know much about reoxing but it sounds
>>preliminary and fraught with problems that'll drive costs sky high.
>
>Why? The USAF does flight refuelling every day, quite routinely, at modest
>cost. There's no great mystery to it; "this isn't rocket science" :-).
I read about a jillion articles on this a couple of months ago and don't wish
to reopen the subject.
>
>>Near SSTO stuff will be light weight payload delivery.
>
>Why? The JATO-assist schemes take the full vehicle into orbit. The
>kick-stage schemes don't, but there's no reason why the payload has
>to be small. (American Airlines doesn't bring the whole aircraft to
>the door of your destination either.)
I assumed near SSTO is a weight limited vehicle (or else you'd go on to
orbit).
Michael Gallagher
>> proven for recovering launch vehicle stages, and you have to test it
and
>> prove it before you can use it. And that's going to take years and
money.
>>
[Description of R&D program, then:]
> The whole program should take about 48 months
>and cost $1,400 million to complete ...
The only launcher that I know of that was developed that quickly was
OSC/Hercules' Pegasus --- and they got away with moving so fast because
it's a solid-fueled ELV. Even with your launcher using "off the shelf"
engines, I think you'll be very lucky if you're even half-way finished
after four years. Every test will require a lengthy evaluation process,
whether it succeeds or fails.
If VTVL RLVs already existed, you would have it easy by building a new
model. But you've got to do a lot of basic R&D, which might take longer
than you think. So I stand by my original assertion:
>> I'm not AGAINST waht you want to do; I just
>> want to point out that it's easier said than done.
>
>Maybe.
Try "probably."
Henry Spencer
>> ... Quite a few of the new launch outfits have noticed that towers are
>>of very limited utility ... Taurus doesn't use a tower, and I don't
>>think LLV does either.
>
>REQUIRES towers for fueling.
Uh, so? Are you under the impression that towers are required for fueling
of liquid-fuel rockets? Not so, not even if the rocket is multi-stage.
See my original posting.
>Furthermore, since Taurus is designed to be
>launched from a site offering no more than a concrete slab, they errect a
>temporary scaffolding as they assemble the rocket, and take it down
>before launch...
I'm not sure what you're trying to say here. I make a distinction --
which was mentioned in my original posting -- between fixtures used for
assembly and erection, and the classical umbilical tower which remains
in place until launch.
John Childers
>"William H. Mook, Jr." <w...@mail.GANet.NET> wrote:
>>
>>
>>Its and unpiloted vehicle that separates outside the atmosphere with
>>near optimal stage fractions. It uses an SSME on the first stage and
>>four RL10s on the second stage .... Vertical landing of both stages is
>carried out
>>through a powered touchdown of the stages ... It uses no really new or
>>advanced technology ...
>>
>The SSMEs aren't new, but I wouldn't call them "not advanced." At the
>very least, they're a finiky peace of machinery, requiring a decent
Advanced does not have to mean expencive or complex. It should mean
the oppisite! :-) Would you call a 1975 Ford advanced today?
>
>And then there's the vertical landing concept, which has barely been
>touched on by DC-X and NEVER used in any launch vehicle! Ok, I'll allow
>Surveyor, Viking, and the Lunar Modules, but those are vehicles that
>lnaded on OTHER PLANETS. Verticla landing has never been used to recover
>launch vehicles. You're making your job easier by doing this in two
Who many horizontal landing launch vehicles have there been? There's the
Shuttle and there's the ummm ... Shuttle. It's never been done does not
mean it's a bad idea, especially when it has only been done once by any
means!
>stages instead of one, but the fact remains both stages will have to
>carry extra fuel for landing. Tha'ts not even remortely an "off the
>shelf" technique. (And also why horixontal landings are nicer --- no
>feule required beyond the needs of your retros.)
But you do have to pay for and carry around wings, areo controls, extra
hydrolics, extra control systems, and extra structure. It's a trade off.
Since you have to have the vertical systems for launch any way, make the
rockets throttlable and add some cheep fuel.
---
John Childers | ===+========:+:
UNC Charlotte | _/ \_ |
Internet? Try | |\ /| -);
jech...@uncc.edu | | X |
--------------------------| __________|/_\|___ .^.
Disclaimer? Does anyone | |Caution Spacecraft| /|=|\
on the net ever officially| |Under Construction| |_____|
speak for their computer? | |/\/\/\/\/\/\/\/\/\| / ^ ^ \
--------------------------------------------------------------
'Larry' L Gales
> >>Near SSTO stuff will be light weight payload delivery.
> >
> >Why? The JATO-assist schemes take the full vehicle into orbit. The
> >kick-stage schemes don't, but there's no reason why the payload has
> >to be small. (American Airlines doesn't bring the whole aircraft to
> >the door of your destination either.)
>
> I assumed near SSTO is a weight limited vehicle (or else you'd go on to
> orbit).
By that reasoning the Saturn V is for light weight payloads because
the 1st stage doesn't go all the way to orbit either. An NSSTO (Nearly SSTO)
can deliver as large a payload as you wish, if fact it delivers a
payload 2-4 times as large as does an SSTO for a given vehicle size
and weight (the NSSTO part, that is, not counting the zero- or cheater-
stage).
-- Larry Gales
Michael Gallagher
>
>In article 1b...@usenetw1.news.prodigy.com, MMF...@prodigy.com (Michael
Gallagher) writes:
>>
>>And then there's the vertical landing concept, which has barely been
>
>(How) many horizontal landing launch vehicles have there been? There's
>Shuttle and there's the ummm ... Shuttle. It's never been done does not
>mean it's a bad idea, especially when it has only been done once by any
>means!
>
True, the shuttle is the first launch vehicle to use a horizontal dead-
stick landing ... but the technique had been tested and evaluated before
the shuttle was ever built, using the X-15 and various and sundry lifting
bodies. It wasn't like they were trying it for the VERY first time. In
contrast, powered vertical landings have never been used for recovering
spacecraft, and are only now being tested in the DC-X. Anyone trying to
privately develop any kind of VTVL landing vehicle --- SSTO or TSTO ---
will either have to wait on the DC-X trials or try to convinve investors
to poor money into the private R&D for the technique. And that adds to
the cost of development, as well as stretching the program (especially if
something goes wrong). I'm not saying it SHOULDN'T be done; I'm saying
you shouldn't fool yourself at how big this job might be.
Charles Buckley
Is the Russian recovery capsules completely unpowered? I was
under the impression that they used rocket assisted landings.
That is about as close a bearing as the X-15 horizontal landings to
the shuttle landing.
Charles Buckley
Edgar Zapata
>In article <4bmjrg$v...@usenetw1.news.prodigy.com> MMF...@prodigy.com (Michael Gallagher) writes:
>>> ... Quite a few of the new launch outfits have noticed that towers are
>>>of very limited utility ... Taurus doesn't use a tower, and I don't
>>>think LLV does either.
>>
>>Bad examples: both Taurus and LLV are solid fueled rockets, so neither
>>REQUIRES towers for fueling.
>
>Uh, so? Are you under the impression that towers are required for fueling of liquid-fuel rockets?
For a cryo fueled rocketsuch as Shuttle it should be noted that the
towers as needs could be classified as "access" (due to poor
supportability), "hazards" (no free hydrogen venting) and "lack of
robustness / more hazards" (no ice allowed; the tile is not robust enough
for ice debris, such as from a GOX vent at the top of a tank.)
To remedy this, free venting would have to be demonstrated safe in a
rigorous test process with more than worst case conditions so as to leave
margin in less exact operations. Also, the vehicle skin would have to be
able to take blows. An aircraft like structure would likely do - of
course for the spacecraft, it would also have to be zero maintenance and
take the reentry heat. The zero maintenance would address a fraction of
the access requirement but this would really be a reliability and
supportability issue (for other parts).
As for the other needs for towers, such as purges and electrical
connectors, this is a matter of rerouting to ground (partly a weight
issue).
--
Edgar Zapata, NASA Kennedy Space Center
Shuttle LOX and External Tank Systems Engineer
For Next Generation:
RLV: http://calvin.ksc.nasa.gov:1080/nexgen/rlvhp.htm
George Herbert
>Henry writes:
>>Why not? Aerospace hardware costs are much more a function of parts count
>>than of size; making things big and simple and dumb *is* a promising idea.
>>Many of the people who have investigated the notion say that it does have
>>the potential for that order of magnitude. (Incidentally, some of us are
>>after multiple orders of magnitude, but that's another issue.)
>
>If we can PROVE an order of magnitude cost reduction right now, we'd be smart
>to put SSTO on back burner and go do BDB. I don't think we can prove it.
You can't "PROVE" anything, about SSTO or BDB or any other new technology,
at this stage in the game. Faith in certainty about the future is not some
quality you find in good engineers and technologists... if we *knew*, we
wouldn't be sitting here talking about it.
That having been said, let's look at the well-researched credible range
of costs... for BDB, anyone with half a brain can build a BDB under $1k/lb,
based on the studies. There are a number in the $250-$500/lb range.
There's your order of magnitude.
SSTO can, if the flight volume is good enough, come in under $100/lb.
Assuming the operations costs come down enough, the limiting factor is
paying off the initial investment in R&D and building the vehicles,
which could be $2 to 10 billion or more.
Obviously, for a thousand flights a year, SSTO has advantages. But the
known market today isn't that large. If someone can afford to sink the
development costs (either long-term commercial investment, or getting
the government to pay for it) then SSTO will work nearterm, probably.
If not, we should keep doing R&D on SSTO vehicles and work on BDB to
bring costs down nearterm and build up the flight rates. BDB are not
the long term answer, but under this scenario they'd firm up the market
to support SSTO as the long term answer.
-george william herbert
Retro Aerospace
gher...@crl.com
William H. Mook, Jr.
>
> buc...@refuge.Colorado.EDU (Charles Buckley) wrote:
> >
> >Is the Russian recovery capsules completely unpowered? I was
> >under the impression that they used rocket assisted landings.
> >
> engine just before touch-down to soften the landing. VTVL proposes
> designing a launch vehicle stage with the capacity to make a verticla
> landing SOLELY UNDER POWER FROM ITS OWN ENGINES after separation/reentry.
> The two are not the same thing.
Well Mike, a couple of things come to mind after reading your thread:
(1) The areal loading of an empty booster is pretty darn close to
the areal loading of a partly deployed parachute. That is,
terminal velocity is pretty darn low. Also, attitude control,
etc., during descent will be largely aerodynamic, lifting body
style. Our form factor won't have a very large L/D ratio, that's
all. So, in many ways recovering a big thin walled tank following
reentry *is* like the Russian practice of using rockets to cushion
a parachute crash. In fact the stage shapes come from some early
studies done prior to Mercury going up. We think we can recover
tanks with something like 2.5% booster empty weight dedicated to
excess propellant. With 12% structural fraction we're talking
about 0.3% total vehicle weight. Even so we've done our early
analysis assuming Mach 1.0 terminal velocity. This ups our
propellant fraction to 8.4% bew increasing total recovery propellant
to 1% - which will be reduced as we gain experience.
(2) We've studied this problem extensively. We've determined the
approach we've selected as being the lowest risk, least cost
way of dealing with a lightweight reusable tank & engines. We've
come to the conclusion that a "son of Shuttle" or "son of Nasp"
wouldn't cut it for what we were doing. We thought about para-
chutes, but putting parachutes on an empty liquid hydrogen tank
was just about useless. We've estimated this to cost about $300
million and take 18 months. If you think this figure is optimistic
then I'd like to know (a) Why? (b) What figure would be realistic
in your estimation? (c) Why is your figure superior to our analysis?
(d) How does this impact our project's overall profitability?
As a final note please recall that the LEM training vehicle was a VTVL
spacecraft used to train Apollo Lunar astronauts. It took a few tens of
millions and a few months to develop. Its total delta vee and control
regime was far superior to our little recovery system. It was also a
piloted vehicle which made it even more expensive than anything we're
planning to do. It operated on Earth.
Doug Hendrix
<Pine.A32.3.91j.95122...@homer07.u.washington.edu>,
'Larry' L Gales <lar...@u.washington.edu> wrote:
>> I assumed near SSTO is a weight limited vehicle (or else you'd go on to
>> orbit).
>=============================================
>By that reasoning the Saturn V is for light weight payloads because
>the 1st stage doesn't go all the way to orbit either. An NSSTO (Nearly SSTO)
>can deliver as large a payload as you wish, ....(snipped)
Too much egg nog on my part. If you think of the NSSTO as a first stage, then
it does become a more efficient payload delivery system. But there could be
payload (includes the 2nd stage) space problems and you may be unable to bring
anything back from orbit (ISSA need-riment). The utility of these various
launch vehicle soutions mentioned depend upon what the vehicle is required to
do. As I see things, that's where the problem in agreeing upon what needs to
be built lies. It's not easy to reach consenus on requirements and everyone's
pushing seperate agendas.
Michael Gallagher
>
>Is the Russian recovery capsules completely unpowered? I was
>under the impression that they used rocket assisted landings.
>
Russians capsules descend by parachute and fire a small solid-fueled
engine just before touch-down to soften the landing. VTVL proposes
designing a launch vehicle stage with the capacity to make a verticla
landing SOLELY UNDER POWER FROM ITS OWN ENGINES after separation/reentry.
The two are not the same thing.
"It only takes ten seconds to describe it, and I'll do it for you in a
William H. Mook, Jr.
>
> For a cryo fueled rocketsuch as Shuttle it should be noted that the
> towers as needs could be classified as
>"access" (due to poor supportability),
The GreenSpace vehicle requires no external access immediately
prior to launch, so this tower is not needed. Prior to fueling
the stages are 'stacked' using a small mobile crane. Pneumatic
clamps hold the second stage landing gear to the first stage
forming a transtage from the second stage landing gear.
>"hazards" (no free hydrogen venting) and
>"lack of robustness /more hazards" (no ice allowed; the tile
>is not robust enough for ice debris, such as from a GOX vent
>at the top of a tank.)
Heh.. the primary heat sheild is oriented to avoid this hazard.
The heat shield is on the base of the cone which is underneath
the vehicle. There are strakes and doors, but these are fully
retractable.
> To remedy this, free venting would have to be demonstrated safe in a
> rigorous test process with more than worst case conditions so as to leave
> margin in less exact operations. Also, the vehicle skin would have to be
> able to take blows. An aircraft like structure would likely do - of
> course for the spacecraft, it would also have to be zero maintenance and
> take the reentry heat. The zero maintenance would address a fraction of
> the access requirement but this would really be a reliability and
> supportability issue (for other parts).
>
> As for the other needs for towers, such as purges and electrical
> connectors, this is a matter of rerouting to ground (partly a weight
> issue).
Interesting... we're ending up in our ground support design with two simple
flagpoles that're hinged on the bottom with propellant and power feeds.
They also carry big vacuum lines - like the exhaust vents on your dryer
that pull venting gases away from the launch site during fueling. These
lean on the side of the vehicle and are pulled away by the flagpoles. All
the cables and such snake down the outside of the vehicle.
Our vehicle is supported by the first stage landing gear prior to launch.
This gear hooks into hold down clamps that are anchored into the ground
prior to launch. So, you basically have four remote controlled hold down
clamps and two flagpoles with wires and vent tubes and feed lines running
up them. Communication is via radio link tied into the CPU bus for each
stage. Actually each stage is computationally integrated as are all
data monitors. (There are three equivalent systems on board)
The payload is attached to a payload interface module along with its
deployment gear. The payload is mounted in the payload bay before
the second stage is hoisted to its place atop the first stage. The
payloads are put in the second stage while its laying on its side
in the transport trailer.
We looked at the result of all this thinking and it seemed like a lot
lot less than what NASA was doing. This made us simultaneously nervous
and happy. Nervous because we thought we might be missing something.
Happy, because if we looked a lot like a NASA launch, we'd likely not
save much money over NASA's costs! :)
So launch proceeds by
(1) Inspecting & testing returned vehicle.
(2) Refurbishing returned vehicle.
(3) Installing PIM into payload bay of second stage.
(4) Erecting first stage at launch center.
(5) Erecting second stage on top of first stage.
(6) Power up stages, final test, install ignitors.
(7) Fill stages with propellant.
(8) Close vent valves, pressurize, start APUs, cycle controls
(9) disconnect external power and propellant feeds.
(10) Start propellant pumps, ignite engines, thrust run up.
(11) Cycle and center controls, release hold down
Michael Gallagher
>
>In article <4bmjrg$v...@usenetw1.news.prodigy.com> MMF...@prodigy.com
(Michael Gallagher) writes:
>>> ... Quite a few of the new launch outfits have noticed that towers
are
>>>of very limited utility ... Taurus doesn't use a tower, and I don't
>>>think LLV does either.
>>
>>Bad examples: both Taurus and LLV are solid fueled rockets, so neither
>>REQUIRES towers for fueling.
>
>Uh, so? Are you under the impression that towers are required for
fueling
>of liquid-fuel rockets?
>
That wasn't my point. You were talking about fueling liquid-fueled
rockets without towers, and you used Taurus as an example of a booster
that doesn't have a tower. MY point is you can'y use it as an example of
a tower-less liquid-fueled rocket because it isn't a liquid-fueled rocket
in the first place! Ok?
Michael Gallagher
>>
>> buc...@refuge.Colorado.EDU (Charles Buckley) wrote:
>> >
>> >Is the Russian recovery capsules completely unpowered? I was
>> >under the impression that they used rocket assisted landings.
>> >
>> Russians capsules descend by parachute and fire a small solid-fueled
>> engine just before touch-down to soften the landing. VTVL proposes
>> designing a launch vehicle stage with the capacity to make a verticla
>> landing SOLELY UNDER POWER FROM ITS OWN ENGINES after
separation/reentry.
>> The two are not the same thing.
>
> reentry *is* like the Russian practice of using rockets to cushion
But not EXACTLY the same. You still have to do a decent amount of
testing to verify the technique. It's only just been tested by DC-X,
and you will have to do your own testing program.
>We've estimated [the R&D] to cost about $300
> million and take 18 months. If you think this figure is
optimistic
> then I'd like to know Why ... ?
Because data has to be analyzed, even if the test is successful. And
because MORE analysis is done if something goes wrong and the thing
explodes! So I remain skeptical.
Allen Thomson
[snip]
>That wasn't my point. You [HS] were talking about fueling liquid-fueled
>rockets without towers, and you used Taurus as an example of a booster
>that doesn't have a tower. MY point is you can'y use it as an example of
>a tower-less liquid-fueled rocket because it isn't a liquid-fueled rocket
>in the first place! Ok?
>
Aren't the Russian SL-11 and -14 (Tsiklon) boosters already fueled
when they're transported horizontally to the pad?
Jim Kingdon
> be smart to put SSTO on back burner and go do BDB. I don't think we
> can prove it.
It is not either/or. And the big dumb booster projects currently
underway are so mind-bogglingly cheap to develop ($25 million for
Microcosm--including an orbital vehicle; I don't know the figure for
PA-X but I would guess it is small too), that there is no need to
start thinking in terms of taking money from SSTO and giving it to big
dumb boosters (or vice versa).
Doug Hendrix
kin...@harvey.cyclic.com (Jim Kingdon) wrote:
Sorry, I'm not familiar with either of these. Maybe you can point me toward an
omline info source? $25M doesn't sound like much of a program...are these
industry led, pressure fed engines programs or something on that order? I
don't think you can "develop" much of anything space going for $25M.
George Herbert
>Sorry, I'm not familiar with either of these. Maybe you can point me toward an
>omline info source? $25M doesn't sound like much of a program...are these
>industry led, pressure fed engines programs or something on that order? I
>don't think you can "develop" much of anything space going for $25M.
Microcosm is at:
http://www.earthlink.net/~microcosm/
It's using industry led pressure fed engines, clusters of smallish engines
(5klb thrust class) based on an all-composite chamber and nozzle technology,
if I understand correctly. No machining except in the propellant feed system
and nozzles, probably.
$25m is probably over 250 engineer-years at small industry salary loadings.
That's more than enough for a big dumb 1-ton-to-LEO class vehicle.
Henry Spencer
>>Are you under the impression that towers are required for fueling of
>>liquid-fuel rockets?
>
>towers as needs could be classified as "access" (due to poor
>robustness / more hazards" (no ice allowed; the tile is not robust enough
There's a false dichotomy here: no tower does not imply free venting.
Just run a vent line down the side, connecting to permanent vent plumbing
in the pad.
As for "access"... Access for *what*? If you put the vehicle together
and test it before rollout, you don't need elaborate access on the pad.
Look at Ariane 5, which has only a stumpy little umbilical mast on the
pad, or Proton, which doesn't even have that. This works partly because
these vehicles are built around a philosophy of minimizing on-pad work.
(Ironically, this was also the basic philosophy for KSC. The one time
NASA actually made a strenuous effort to do things that way -- for the
Skylab workshop -- it worked very well and saved quite a bit of money.)
>...Also, the vehicle skin would have to be
>able to take blows. An aircraft like structure would likely do...
Do note that Atlas and the Saturns used uninsulated LOX tanks, which grow
a layer of ice during fuelling and shed it at launch, with no particular
difficulties in this area. Agreed that you can't do it if you've got
something as fragile as the shuttle tiles exposed.
Frank Crary
>I dispute the assertion that the weight of the fuel needed for
>vertical landing (assuming by 'fuel' you actually mean propellant)
>is less than the horizontal landing hardware. Most studies that
>examine horizontal landers wind up with 5-6% of the landed mass
>allotted to HL-specific systems.
I'm afraid I don't understand this statement. The Shuttle is
an example of a horizontal landing system. Are you seriously
suggesting that the wings and tail account for only five
or six percent of the landed Shuttle's mass? I think the
number is closer to 50%. Certainly, more modern systems
could reduce that, but by an order of magnitude in "most"
cases? I find that very difficult to believe.
Frank Crary
CU Boulder
Henry Spencer
>>Many of the people who have investigated [BDB] say that it does have
>>the potential for that order of magnitude...
>
>If we can PROVE an order of magnitude cost reduction right now, we'd be smart
>to put SSTO on back burner and go do BDB. I don't think we can prove it.
The only way you *prove* it is to build it. Nothing less will convince
the die-hard naysayers, who think it is a law of nature that launches cost
$5000/lb and always will. Nobody's yet put up the money for that.
But even if you are convinced that BDB will deliver the order of magnitude,
it is *not* smart to put SSTO on the back burner. SSTO offers potential
for more than just one measly order of magnitude.
>>>I don't know much about reoxing but it sounds
>>>preliminary and fraught with problems that'll drive costs sky high.
>>Why? The USAF does flight refuelling every day...
>
>I read about a jillion articles on this a couple of months ago and don't wish
>to reopen the subject.
In other words, you aren't willing to defend your position. I take this
as a concession of defeat. :-)
>>>Near SSTO stuff will be light weight payload delivery.
>>Why? The JATO-assist schemes take the full vehicle into orbit. The
>>kick-stage schemes don't, but there's no reason why the payload has
>>to be small.
>
>I assumed near SSTO is a weight limited vehicle (or else you'd go on to
>orbit).
It's a mass-fraction limited vehicle. Mass fraction is a ratio, not an
absolute quantity. It's quite possible to have very large near-SSTOs.
And you're still ignoring the fact that some near-SSTO schemes supply
the little extra kick at the beginning, not the end, so the vehicle drops
some strap-on boosters and then ascends into orbit.
Henry Spencer
>>of liquid-fuel rockets?
>
>That wasn't my point. You were talking about fueling liquid-fueled
>that doesn't have a tower. MY point is you can'y use it as an example of
>a tower-less liquid-fueled rocket because it isn't a liquid-fueled rocket
>in the first place! Ok?
I was talking about *launching* without towers. You're the one who
decided that the discussion was specifically about fueling.
While solid-fuel rockets don't have to worry about getting fuel into the
upper stages, by the way, typically they *do* have to worry about arming
the igniters and other pyros in the upper stages. This sort of thing is
one reason why NASA tends to insist on towers, but other people seem to
be able to do without somehow.
Incidentally, I did supply an example of a tower-less liquid-fuel rocket,
in fact a rather large one. Name begins with "P"...
Henry Spencer
>True, the shuttle is the first launch vehicle to use a horizontal dead-
>stick landing ... but the technique had been tested and evaluated before
>the shuttle was ever built, using the X-15 and various and sundry lifting
>bodies. It wasn't like they were trying it for the VERY first time. In
>contrast, powered vertical landings have never been used for recovering
Why are aircraft examples relevant for HL but not for VL? Powered
vertical landings are used for recovering aircraft every day, by almost
every military force on Earth and many civilian operators. Even if you
exclude helicopters as too different to be relevant -- a decision I would
argue with -- there are still half a dozen military arms, including the
USMC, flying jet-lift fighters every day.
Henry Spencer
>...Most studies that
>examine horizontal landers wind up with 5-6% of the landed mass
>lander with less than ten percent of its mass at landing set aside
>for landing propellant. (Think of it as thirty seconds).
As I've said in the past, I don't dispute Mitch's calculations but I do
dispute some of the assumptions underlying them (and the HL studies he
refers to).
As a case in point, the VL studies are for powered landings. The HL studies
are not. To make the comparison realistic, the HL studies must include a
go-around capability, which most of them lack at 5-6%. How much does this
add? Well, off the top of my head, assume we need a delta-V of 100m/s for
a worst-case go-around; that's enough added energy to return to maybe 2000ft,
depending on details. That's equivalent to ten seconds of hover, another
3-4% of landed mass. Suddenly the difference looks a lot smaller...
Of course, you can say that we don't need go-around because we'll always
land right the first time. In which case, I can say that we don't need
thirty seconds of fuel for VL, because the guidance problem is, if
anything, rather simpler for VL. We need maybe ten seconds, speaking
very conservatively, to kill the terminal velocity. Now we're talking
5-6% for HL and 3% for VL.
I would also observe that there are mass penalties in systems which don't
look HL-specific at first glance, such as primary structure (more varied
loads from more points and more directions) and thermal protection (larger
area and [assuming a high-L/D reentry] more prolonged heating).
Daniel Risacher
>>>>> "Frank" == Frank Crary <fcr...@rintintin.Colorado.EDU> writes:
Frank> In article <4bnekm$o...@news1.delphi.com>, burnside
Frank> <burn...@bix.com> wrote:
>> I dispute the assertion that the weight of the fuel needed for
>> vertical landing (assuming by 'fuel' you actually mean
>> propellant) is less than the horizontal landing hardware. Most
>> studies that examine horizontal landers wind up with 5-6% of
>> the landed mass allotted to HL-specific systems.
Frank> I'm afraid I don't understand this statement. The Shuttle
Frank> is an example of a horizontal landing system. Are you
Frank> seriously suggesting that the wings and tail account for
Frank> only five or six percent of the landed Shuttle's mass? I
Frank> think the number is closer to 50%. Certainly, more modern
Frank> systems could reduce that, but by an order of magnitude in
Frank> "most" cases? I find that very difficult to believe.
Frank> Frank Crary
Frank> CU Boulder
The shuttle is a single design - and like any vehicle suffers from
it's own set of compromises. You can't argue about what is possible,
just by looking at what's been done. Especially not by just looking
at one example!
Here's a more elaborate answer (also by Mitch) borrowed from the Black
Horse FAQ I compiled, which is available at :
http://www.im.lcs.mit.edu/bh/bh-faq.html
Q: Horizontal Lander concepts must drag large mass fractions up
and down in the form of wings. A Vertical Lander could very well
de-orbit and land with a mass of propellant equal to 10% of the
vehicle dry mass; could any HL possibly have wings which are less than
30% of the total dry mass? How many existing aircraft even do that
well?
A: This is not correct. The NASA Access to Space baseline SSTO,
which you can read about in Aersoapce America, has a landed mass of
251,362 pounds. The wing weighs 11,465 pounds, the tail weighs 1,577
pounds, and the control surface actuation weighs 1,549 pounds. This
means that the subsystems that are chargeable to horizontal landing
weigh 5.8% of the landed mass. Of that landed mass, 222,582 pounds is
the vehicle dry mass, the rest being 25,000 pounds of payload and some
residual fluids and such.
For Black Horse, the maximum landed weight is the takeoff weight,
which is 48,454 pounds. The wing (1,572 pounds), tails (739 pounds),
and control surface actuation (372 pounds) together weigh 5.5% of the
landed weight. This aircraft was designed using standard fighter
aircraft design methodology, for which see Raymer, Daniel P.,
"Aircraft Design: A Conceptual Approach" (Chap 15).
For a vertical lander such as the DC-Y, if the landing propellant
weighs 10% of the landed mass, that is the equivalent of adding 1200
feet per second to the overall delta-V the vehicle must produce. That
means a huge difference at the margin, because the additional delta-V
is applied on the steepest part of an exponentially sensitive curve.
(Mitchell Burnside Clapp, cla...@smtpgw1.plk.af.mil)
--
Daniel R Risacher - mag...@mit.edu - http://www.im.lcs.mit.edu/~magnus/
Engineers make life better through cleverness.
Politicians make life worse through stupidity.
Rick Ballard
> Aren't the Russian SL-11 and -14 (Tsiklon) boosters already fueled
>when they're transported horizontally to the pad?
No, it is my understanding that they are transported to the launch pad on a
horizontal carrier (at about T-3 hours), then erected, and then fueled prior to
launch (taking about 1 hour, beginning at T-75 minutes). However, according to the
latest edition of Jane's Space Directory, the third stage of the SL-14 (Tsyklon) is
fueled while horizontal in the vehicle processing building. The SL-11 (Tsyklon) is
a two-stage vehicle and would therefore not be fueled until after it had reached the
launch pad.
I'm not sure about the SL-11/14 booster, but I've seen videos of SL-16 (Zenit)
launch preparation where the vehicle mates up with a special interface adapter on
the launch pad which connects the propellant fill lines with the base of the
vehicle. It was all automated and greatly simplified the launch process. I was
quite impressed by it.
Rick.
---------------------------------------------------------------------
Any opinions expressed in the above message are my own, and does not
indicate any views supported by NASA or Sverdrup Technology.
---------------------------------------------------------------------
Mitchell Burnside Clapp
has a go-around capability.
We know that the thrust, T, for a vertical lander is related to the
required number of g's of deceleration (a), the weight of the vehicle
(W), and the specific impulse (Isp), and the weight flow rate (dW/dt) by:
T = a W = Isp (dW/dt) (1).
We can calculate the landing propellant mass fraction by multiplying by
the time (dt) and rearranging terms:
1 - (W-dW)/W = a (dt)/Isp (2).
This part is just physics. The engineering comes in when you have to put
in some numbers. I will use the sea level Isp of the SSME at 370.7 sec.
The value of (a) is a little harder to substantiate, but McDonnell
Douglas is decelerating at 2 g's after a 5 second chilldown period last I
heard, then throttling back to 0.8 g's only at the very end. Let's skip
the chilldown part and say that it all time-averages out to 1.5 g of
deceleration.
Under these assumptions, with no other margins for anything, a vertical
lander can just squeak down with four percent of its landed mass consumed
in ten seconds. This is enough to kill a terminal velocity of 288 knots,
assuming no control penalties, no chilldown, and deceleration to a
perfect stop exactly on the pad, with no winds.
Chilldown consumes, at a bare minimum, four seconds of equivalent
full-flow propellant. Residuals for LO2/LH2 systems run about 1% of tank
capacity in a well-designed system. Control penalties (steeering,
targeting, and the like, to enable the vehicle to land on its intended
point, again with no margin or reserve) would, I assert without proof,
consume an additional 30 percent of the landing fuel. The result is an
equivalent time of (10+4)* 1.3 * 1.01 seconds, giving 7.4 percent
propellant at landing. Most prudent VTVL designers add some margin to
take care of things like winds and so on, which adds about another 5
seconds of flight time. This brings you up to a ten percent propellant
mass fraction at landing, and you still don't have anything like what a
pilot would call a go-around capability.
Mitchell Burnside Clapp
X-33 Operations Officer
--
1965 1975 1985 1995
Small Car VW Beetle VW Rabbit Honda Civic Dodge Neon
Fighter F-4 F-15 F-117 F-22
Passenger Jet 707 747 767 777
Space launch Delta Delta Delta Delta
Atlas Atlas Atlas Atlas
Titan Titan Titan Titan
The opinions expressed here are solely my own, and do not reflect
those of the USAF, DOD, or anyone else.
George Herbert
>Big Dumb is 1 ton LEO? I'd call that Small Dumb, I guess. Also, engineering
>manpower alone doesn't represent a development program. What about testing and
>hardware for testing, hardware procurement, etc.
BDB is more of a philosophy than a size indication. It scales up nicely
and gets cheaper the larger you get (to a point), so people looking at
large launch manifests typically design large ones to get the cost down
on a per-lb basis. But you can design small ones, which will cost 1/10 of
current small launcher costs... just like big ones will cost 1/10 of current
big launcher costs. Perhaps someone should invent a new term for BDB's
which is less size-dependent to prevent confusion.
You are correct that engineering manpower alone isn't a whole development
program, by any means. But the $100k/engineer-year "loaded cost" includes
some equipment purchases, etc. It's a massive simplification to say that
you're just paying engineers, but that was the dominant cost driver
(nearly half) when I was doing detailed task and timeline work on BDB
development programs 2 years ago for one of Retro's vehicle designs.
Microcosm is making prototype engines for $5k each. Assuming this doesn't
go down over time, and it takes them 10 engineer years at $75k of
salary+overhead and 50 prototype rocket motors to get right, then they
are looking at $1m for development of the motors. Which, based on their
initial results, seems to be wildly pessimistic.
Designing the tanks is trivial. Anyone who paid attention through third or
fourth year in a university engineering program should be able to do a
decent tank in a year, engineering wise, by themselves. Pressure fed rockets
using steel tanks are *cheap* to design the tanks.
>This is kinda typical of what keeps me confused in this group. People write
>about programs and developments and the tone of the writing convinces me that
>there really is something going on when it's just a concept of what they want
>to be going on. I'm not saying that microcosm isn't happening, I'll have to
>read more about that but it was given as a big dumb bosster project and
>apperently it isn't the case.
It's a dumb booster project. They've done a hell of a lot of the needed
development with less than $2 million spent so far. It may not be big, but
it is in a size class (Taurus, LLV, Conegesta) which seems to have payloads
waiting to fly, and they are looking at $1.7m/launch instead of $15m/launch
which the conventional companies are looking at charging. If Scorpius works
as advertised, they stand to sell zillions of them.
It makes some sense to start small. Investment capital has been the number
one failure point for startup launch vehicles over the years. The less you
need of it the easier it is to get started and over that initial hump.
Doug Hendrix
Doug Hendrix <nhen...@ren.com> wrote:
>>Sorry, I'm not familiar with either of these. Maybe you can point me toward
an
>>omline info source? $25M doesn't sound like much of a program...are these
>>industry led, pressure fed engines programs or something on that order? I
>>don't think you can "develop" much of anything space going for $25M.
>
>Microcosm is at:
>http://www.earthlink.net/~microcosm/
>
>It's using industry led pressure fed engines, clusters of smallish engines
>(5klb thrust class) based on an all-composite chamber and nozzle technology,
>if I understand correctly. No machining except in the propellant feed system
>and nozzles, probably.
>
>$25m is probably over 250 engineer-years at small industry salary loadings.
>That's more than enough for a big dumb 1-ton-to-LEO class vehicle.
Big Dumb is 1 ton LEO? I'd call that Small Dumb, I guess. Also, engineering
manpower alone doesn't represent a development program. What about testing and
hardware for testing, hardware procurement, etc.
This is kinda typical of what keeps me confused in this group. People write
Michael Gallagher
>
>In article <4bu969$1c...@usenetw1.news.prodigy.com> MMF...@prodigy.com
(Michael Gallagher) writes:
>>>Uh, so? Are you under the impression that towers are required for
fueling
>>>of liquid-fuel rockets?
>>
>>That wasn't my point. You were talking about fueling liquid-fueled
>>rockets without towers, and you used Taurus as an example of a booster
>>that doesn't have a tower. MY point is you can'y use it as an example
of
>>a tower-less liquid-fueled rocket because it isn't a liquid-fueled
rocket
>>in the first place! Ok?
>
>I was talking about *launching* without towers ...
The phrase you used was "USE a tower." Obviously, you meant one thing by
that, and I meant another.
>Incidentally, I did supply an example of a tower-less liquid-fuel rocket,
>in fact a rather large one. Name begins with "P"...
>--
The Proton, yes .... but in the next sentence you mentioned Taurus and
LLV. With the latter two being solids and the former being liquid, I
just didn't think they belonged together in the same example. Apples and
oranges both grow on trees, but there's still that rule about not
comparing them!
Beyond that, let's drop it. Because beyond semantics, it's not THAT big
a deal.
Jim Kingdon
I've been wondering what terminology to apply in this case too. These
dumb (pressure-fed) designs are big compared with other designs with
similar payload, but even so "Dumb" is perhaps more appropriate than
"Big Dumb".
> Also, engineering manpower alone doesn't represent a development
> program. What about testing and hardware for testing,
My impression is that the $25 million would include that (up to one
orbital test), but I'm not sure there were details. Microcosm already
have built 5 or 6 of their engines, so this isn't one of those
programs where you pay a lot of development up front and only later do
they start building hardware.
> hardware procurement
This is a research project. If it produces an operational capability,
I would assume it would be procured similarly (and no more
expensively) than Pegasus, etc., flights are procured now.
> This is kinda typical of what keeps me confused in this group.
Nothing unique about usenet in that respect. One finds the same sort
of thing in the press, the floor of congress, etc. Only by taking the
effort to look carefully at details like what costs are and are not
included in a figure which is being tossed around, what is meant by
terms like "Big Dumb Booster", etc., can one hope to keep it straight.
Doug Hendrix
>I'm not saying that microcosm isn't happening, I'll have to
>read more about that but it was given as a big dumb bosster project and
>apperently it isn't the case.
I looked at the site. This "industry led" project has been financed so far by
the Air force. While it sounds like some very good work has been accomplished,
I found no $500/lb Vehicle capability. They listed several classes of
Vehicles:
$4100/lb - SR-3 micro lift (170 lbs LEO)
$7700/lb - Liberty Light lift (2200 lbs LEO)
$5200/lb - Exodus Medium Lift (15,000 lbs LEO)
These are still good prices but I was told that BDB were right around the
corner with a $500/lb cost. Where?
Doug Hendrix
>I'm not saying that microcosm isn't happening, I'll have to
>read more about that but it was given as a big dumb bosster project and
>apperently it isn't the case.
I looked at the site. This "industry led" project has been financed so what by
George Herbert
>I looked at the site. This "industry led" project has been financed so far by
> I found no $500/lb Vehicle capability. They listed several classes of
>Vehicles:
>
> $4100/lb - SR-3 micro lift (170 lbs LEO)
> $7700/lb - Liberty Light lift (2200 lbs LEO)
> $5200/lb - Exodus Medium Lift (15,000 lbs LEO)
I think you divided something wrong here, the prices they listed for those
vehicles were $700,000, $1.7m, and $7.9m respectively, which works out
to per-lb prices of $4117/lb (SR-3, you got it right), $772/lb (Liberty),
and $526/lb (Exodus). You seem to have added a decimal point by accident
in the larger vehicles.
Those seem highly credible to me, I was looking at 10 tonne to LEO vehicles
(about the smallest you can do GEO launches with, which is where the bread
and butter commercial market is) for about $10m including amortized development
and per flight costs (and a hefty profit too, to be honest...). They're doing
6.8 tonnes (15,000lb) for $7.9 million, which is only about 10% more per lb
compared to Retro's various on-paper vehicles.
>These are still good prices but I was told that BDB were right around the
>corner with a $500/lb cost. Where?
Well, Exodus is $526/lb as listed, if you minimize math errors 8-)
Doug Hendrix
>I think you divided something wrong here, the prices they listed for those
>vehicles were $700,000, $1.7m, and $7.9m respectively, which works out
>to per-lb prices of $4117/lb (SR-3, you got it right), $772/lb (Liberty),
>and $526/lb (Exodus). You seem to have added a decimal point by accident
>in the larger vehicles.
>
I have got to get a new calculator! Sorry for the mis-info ... You're right.
The only problem then seems to be that this $25M program have been funded to
the tune of $2M so far. I wonder if the rest of the funding will come.
Incidently, I suspose that James Wertz is the same person whose book(s) are in
my bookcase?
Joshua B Hopkins
>In article <4bu969$1c...@usenetw1.news.prodigy.com> MMF...@prodigy.com (Michael Gallagher) writes:
>[snip]
>>That wasn't my point. You [HS] were talking about fueling liquid-fueled
>>rockets without towers, and you used Taurus as an example of a booster
>>that doesn't have a tower. MY point is you can'y use it as an example of
>>a tower-less liquid-fueled rocket because it isn't a liquid-fueled rocket
>>in the first place! Ok?
>>
> Aren't the Russian SL-11 and -14 (Tsiklon) boosters already fueled
>when they're transported horizontally to the pad?
I believe that the first and second stages are unfueled, and are fueled
on the pad. The first edition of Isakowitz states that "When the rocket
is placed vertically on the launch pad, manual access to the rocket
and payload is absent." I don't have any photos of the launch facility
handy, so I don't know if there is an umbilical tower, but I'm sure
that if there is, it's pretty minimal.
Proton has no launch tower, and neither does Zenit. (Well, technically
there are "towers" at the launch facility for things like lights and
presumably for lightning rods -- but this is a completely different
issue.) Both of these are large, liquid fueled boosters. It's pretty
clear that towers are not a major requirement for anything but
crew-launch vehicles, or biological sample which have to inserted in
an experiment at the last minute.
--
Josh Hopkins jbho...@uiuc.edu
The problem with the Global Village is that its inhabitants
include a planetful of village idiots.
Doug Hendrix
>>>>Uh, so? Are you under the impression that towers are required for
>>>>fueling of liquid-fuel rockets?
but another reason for towers is crew or passenger egress. It would make me
very uneasy to be in a liquid prop. vehicle with no convienient way to get
out/off.
Henry Spencer
>Proton has no launch tower, and neither does Zenit...
>Both of these are large, liquid fueled boosters. It's pretty
>clear that towers are not a major requirement for anything but
>crew-launch vehicles, or biological sample which have to inserted in
>an experiment at the last minute.
Even vehicles which do have on-pad access, like the shuttle, typically
want loading of things like biological samples to be complete several
hours before launch. This could be handled without on-pad access, for the
most part, if you adopted a philosophy of "roll it out, fill it up, and
launch it". Not even the Russian launchers go quite that far toward
minimizing on-pad time, though... at least, not with their normal
peacetime operational practices.
As for things carrying people... It's interesting to note that Zenit was
meant to replace the "A" series boosters, meaning that it would have taken
over the manned launches among other things. One wonders what would have
been done about crew access.
Allen Thomson
>
>As for things carrying people... It's interesting to note that Zenit was
>meant to replace the "A" series boosters, meaning that it would have taken
>over the manned launches among other things. One wonders what would have
>been done about crew access.
Jim Oberg can probably provide the facts on this, but AIR some sketches
from a few years back showed yet another manned capsule with a hatch
and escape motor in the Soyuz/Mercury/Gemini/Apollo mold. (Not that
I think that's bad.)
Henry Spencer
>>>>>...Are you under the impression that towers are required for
>
>The propellant fueling can be accomodated, perhaps with a vehicle weight scar,
>but another reason for towers is crew or passenger egress. It would make me
>very uneasy to be in a liquid prop. vehicle with no convienient way to get
>out/off.
This can be handled with stairs or ladders -- or, if the vehicle is tall,
a "cherry picker" platform -- that are moved up beside the vehicle as
needed. That's how it's done for liquid-propellant vehicles today, at
every airport in the world. (You may need something different for
*emergency* egress, but as with airliners, that case can be handled
separately.)
William H. Mook, Jr.
>
> "William H. Mook, Jr." <w...@mail.GANet.NET> wrote:
> >
> >Michael Gallagher wrote:
> >>
> >> buc...@refuge.Colorado.EDU (Charles Buckley) wrote:
> >> >
> >> >Is the Russian recovery capsules completely unpowered? I was
> >> >under the impression that they used rocket assisted landings.
> >> >
> >> Russians capsules descend by parachute and fire a small solid-fueled
> >> engine just before touch-down to soften the landing. VTVL proposes
> >> designing a launch vehicle stage with the capacity to make a verticla
> >> landing SOLELY UNDER POWER FROM ITS OWN ENGINES after
> separation/reentry.
> >> The two are not the same thing.
> >
> >Well Mike ... in many ways recovering a big thin walled tank following
> > reentry *is* like the Russian practice of using rockets to cushion
> > a parachute crash ...
>
> But not EXACTLY the same. You still have to do a decent amount of
> testing to verify the technique. It's only just been tested by DC-X,
> and you will have to do your own testing program.
>
> >We've estimated [the R&D] to cost about $300
> > million and take 18 months. If you think this figure is
> > optimistic then I'd like to know Why ... ?
>
> Because data has to be analyzed, even if the test is successful. And
> because MORE analysis is done if something goes wrong and the thing
> explodes! So I remain skeptical.
Well, you didn't really answer the question I asked. You just repeated
your assertion that you are skeptical because data has to be analyzed.
What figures have you come up with that show the 18 months $300 million
figures are optimistic? Why those figures and not the ones we've come
up with? What is it about these figures that make them seem optimistic
to you?
For comparison, didn't DC-X under BMDO management go from concept to
flight in 18 months and cost less than $60 million? If so, by what
reasoning do you say a program building on this (and other) program
will cost more and take longer? Especially given the fact that it
will (a) not go through government procurement process, (b) used
even more advanced computing capabilities than DC-X?
You are basically gratuitously asserting that the GreenSpace program
numbers are overly optimistic without giving any real substance to
your assertions. I take offense at that, especially since I've
asked you nicely twice to provide a real rationale for all your
bad mouthing.
Michael Gallagher
>
>Michael Gallagher wrote:
>>
>> Because data has to be analyzed, even if the test is successful. And
>> because MORE analysis is done if something goes wrong and the thing
>> explodes! So I remain skeptical.
>
>Well, you didn't really answer the question I asked. You just repeated
>your assertion that you are skeptical because data has to be analyzed.
>What figures have you come up with that show the 18 months $300 million
>figures are optimistic? ...
None. Because I don't know how to do such an analysis; I wouldn't know
where to begin.
However, I HAVE noted that with new launchers, without fail, there seems
to be a long lag time in the early flights. The first four shuttle
flights took over a year to complete. The second Pegasus flew a year
after the first. And so forth. And that's when things go RIGHT. So I
don't see why, in the real world, your booster wouldn't have a similar
history for the first few flights. Yes, you'd build up the flight rate
later, but early on, there would probably be longer than normal
tunrarounds.
> ... For comparison, didn't DC-X under BMDO management go from concept
to
>flight in 18 months and cost less than $60 million? ...
DC-X is a relatively small rocket that doesn't go near earth orbit. An
orbital system, by definition, would be a bit more complicated.
> ... If so, by what
>reasoning do you say a program building on this (and other) program
>will cost more and take longer? Especially given the fact that it
>will (a) not go through government procurement process, (b) used
>even more advanced computing capabilities than DC-X?
>
Avoiding the government WILL speed things up, no argument .... but it
also sped up Pegasus, which also had a long turnaround in the early
flights. And P* is a 3-stage solid-fueled rocket, a no-brainer
technology-wise.
>You are basically gratuitously asserting that the GreenSpace program
>numbers are overly optimistic without giving any real substance to
>your assertions. I take offense at that, especially since I've
>asked you nicely twice to provide a real rationale for all your
>bad mouthing.
Sorry I've offended you. But my skepticism remains. Could Greenspace
work? Yes. Could it get up to a high flight rate very early on? ....
No. That's all.
Aside from that, let's agree to disagree and leave it at that.
Jim Kingdon
> expanding industrial capacity then you have a need for larger and more
> numerous launch vehicles.
An expanding industrial capacity needs *cheaper* and more numerous
launch services. One can always work around lower payloads with
on-orbit assembly and other tricks, if the price is low enough to make
up for the additional inconvenience. The commercial airline market is
expanding but the 747 is not the fastest expanding part of it nor do
aircraft larger than the 747 look particularly promising.
Furthermore, all attempts to build commercial 747-sized aircraft in
the 30s, 40s, and 50s were dismal failures--it only makes sense once
the market reaches a certain size.
> I propose there is a "Mook Curve" similar to Moore's curve for
> micro-electronics. As you build larger spacecraft the cost per
> pound is reduced.
I'm skeptical. Pegasus may be the smallest launcher and the most
expensive per pound, but shuttle and Titan IV are the largest and next
most expensive per pound, well more expensive than Atlas or Delta.
The problems of shuttle and Titan IV are no doubt caused partly by low
launch rates, but even aside from that, at very large sizes the
development costs go through the roof and that tips the balance in
favor of smaller sizes. There is an article in the January 1996
Scientific American about this vis-a-vis Moore's law and the
semiconductor industry.
Allen Thomson
in the smallsat tussle:
When in Doubt, Appoint a Panel
Aviation Week and Space Technology
January 1, 1996, p.19
[EXCERPT]
House-Senate intelligence conferees have agreed to temporarily
set aside the contentious issue of whether to begin procurement
of a new generation of smaller reconnaissance satellites. Their
compromise calls for the appointment of a panel of experts. By
May 1, the panel is to determine whether "smallsats" can be
procured immediately, as proponents in the House contend, or
whether several more years of technology development is needed,
as the Senate and National Reconnaissance Office maintain.
If anyone finds out who the panel members are, please post
the information here (if it isn't classified, of course). The
panel's conclusions will, of course, be predetermined by the
experts chosen to "study" the matter.
For the s.s.t. readership: What could plausibly be claimed to be
a technical impediment to small photoreconnaissance satellites?
Michael Gallagher
>
>In article <4bsign$1c...@usenetw1.news.prodigy.com> MMF...@prodigy.com
(Michael Gallagher) writes:
>>True, the shuttle is the first launch vehicle to use a horizontal dead-
>>stick landing ... but the technique had been tested and evaluated
before
>>the shuttle was ever built, using the X-15 and various and sundry
lifting
>>bodies. It wasn't like they were trying it for the VERY first time.
In
>>contrast, powered vertical landings have never been used for recovering
>>spacecraft, and are only now being tested in the DC-X...
>
>Why are aircraft examples relevant for HL but not for VL? Powered
>vertical landings are used for recovering aircraft every day, by almost
>every military force on Earth and many civilian operators. Even if you
>exclude helicopters as too different to be relevant -- a decision I
would
>argue with -- there are still half a dozen military arms, including the
>USMC, flying jet-lift fighters every day.
>--
Many aircraft land horizonatlly, like the shuttle ..... but you couldn't
use a 747 to test the shuttle's landing profile. It comes in unpowered
at a steep angle of attack, and as such it's landing was verified by the
X-15 and landing bodies.
In the same way, yes, you have helicopter AND Harriers (mispellled) AND
the V-22 Osprey which all land vertically ..... but how many of them can
be used to directly verify a tail-first powered landing by a launch
vehicle (stage)? The only vehicle touching on that is DC-X. Period.
Now, if a man-rated VTVL S/TSTO ever flies, yes, a VTVL aircraft can be
used as an inflight simulator, just as a modified gulfstream is used for
shuttle training flights. But for actually verifying the stage recovery,
an aircraft won't do it.
"It only takes ten seconds to describe it, and I'll do it for you in a
minute" -- David Gunson
Michael J. Gallagher aka mmf...@prodigy.com
P. S. Happy New Year!
Mitchell Burnside Clapp
>
> In <30E44A...@plk.af.mil> Mitchell Burnside Clapp <cla...@plk.af.mil> writes:
>
> >Just because the landing is powered does not mean that a vertical lander
> >has a go-around capability.
>
> but not enough for go-around capability. How does this lead to the
> conclusion that a horizontal lander, with no more margin and less
> operational flexibility, is the better choice?
Under the limited terms of the argument presented (compare no-go-around HL with
no-go-around VL) I conclude that HL is the better choice because a: it weighs less
and b: it does not require an engine start (the safety arguments against which
have been made elsewhere). It is also easier to add glide-stretching or an actual
go-around to an HL than it is to a VL, but that's a bit outside the envelope of
the argument I was making.
What is your case for claiming that a VL has better operational flexibility? You
can't just land it any old where. It is wanting in crossrange, typically. You
cannot identify an engine failure until it is too late to do anything about it.
It's not the airless planet argument, is it? I'm interested.
> Changing the subject:
>
> >X-33 Operations Officer
>
> What does that job entail?
Operationally, emptying coffee cups and filling up wastebaskets, much like
everyone's job. It would be much more inmpressive if there were an X-33 flying.
Doug Hendrix
Henry Spencer <he...@zoo.toronto.edu> wrote:
>In article <4bv28o$6...@news.ro.com> nhen...@ren.com (Doug Hendrix) writes:
>>...$25M doesn't sound like much of a program...are these
>>industry led, pressure fed engines programs or something on that order? I
>>don't think you can "develop" much of anything space going for $25M.
>
>The original development budget for Pegasus -- a traditional high-tech
>design with some major novel elements, rather than a simple-and-dumb
>concept -- was only about twice that. I think it ended up overrunning
>its budget a bit, but that's still the right order of magnitude.
>
>The notion that you can't do *anything* in space for less than a billion
>dollars is NASA's single greatest contribution to the stagnation of space
>technology and the postponement of mankind's future in space.
I didn't say it took a billion dollars to do "anything" in space. I just said
$25m didn't seem like much of a program. I've since read nore about this
program (even misinterpeted some info) and have a better idea about what the
program is all about. At the time of my post, this program was listed as an
example of a cheap BDB program. I couldn't connect DBD and $25m. In fact, it's
really not a BDB program but rather a program that may put as much as 15klbs
in LEO. Had that been known at the time, it would have changed my statement.
But, I think doing thing's in Space is still difficult and yes, expensive. It
does nothing to under state cost expectations...I think NASA has learned that
lesson. I expect these Buck Rogers Co.'s will learn the same lesson,
eventually.
Richard A. Schumacher
>Under the limited terms of the argument presented (compare no-go-around HL with
>no-go-around VL) I conclude that HL is the better choice because a: it weighs less
>and b: it does not require an engine start (the safety arguments against which
>have been made elsewhere). It is also easier to add glide-stretching or an actual
>go-around to an HL than it is to a VL, but that's a bit outside the envelope of
>the argument I was making.
Adding that capability to the HL requires building a new vehicle. And the
go-around requires an engine start, in which case you burden every flight
with the mass penalty of an engine(s) and fuel which are not used on the
great majority of normal flights. If you can carry that fuel and highly
reliable engine(s) at all, use them on every flight to land vertically;
dispense with the wings and carry more payload instead.
Richard A. Schumacher
>The shuttle is a single design - and like any vehicle suffers from
>it's own set of compromises. You can't argue about what is possible,
>just by looking at what's been done. Especially not by just looking
>at one example!
The shuttle is the only existing example. The others you mention are
paper studies with no hardware to demonstrate any of the claims made
for them. Further, the paper examples discuss only the *mass* of the
wings, tail, etc., and not their drag during ascent. And consider
operational flexibility during early flights: it's easy for a vertical
lander to carry along a little more or less fuel as needed, but a
horizontal lander cannot carry more or less wing without being rebuilt.
Thank goodness all of these religious arguments will be mooted in a
few years, with any luck.
Henry Spencer
>...$25M doesn't sound like much of a program...are these
>industry led, pressure fed engines programs or something on that order? I
>don't think you can "develop" much of anything space going for $25M.
The original development budget for Pegasus -- a traditional high-tech
design with some major novel elements, rather than a simple-and-dumb
concept -- was only about twice that. I think it ended up overrunning
its budget a bit, but that's still the right order of magnitude.
The notion that you can't do *anything* in space for less than a billion
dollars is NASA's single greatest contribution to the stagnation of space
technology and the postponement of mankind's future in space.