Fragile Space Shuttle
Nutsy Fagen
Okay, another question for you. Every time the shuttle goes up or
comes down, I read about how just about every system is checked, removed,
replaced, etc. I can understand a thorough checkout, and the fact that
space travel is, to say the least, a risky business, but how much of what
NASA does for turnaround would be considered unneccesary in 10-15 years
(Provided the same shuttle design is still running).
Few of us have a problem with a commercial plane ride in bad weather,
yet we read that they can't even roll the shuttle to the pad because of rain!
This also reminds me of just about every nut and fastener being traceable to
who installed it, when, where it came from, etc.
As I said before, I agree that such stringent measures are required
at our current level of knowledge with space travel. What I am really
wondering is how low until things start to 'ease off'. What will be the first
requirements that get dropped? And, when will the astronauts get to stop
wearing those uncomfortable orange suits?
Mike Bunell
MJB8949 @ RITVAX
I R a student
No boss
No disclaimer
no job
Tom Neff
> Okay, another question for you. Every time the shuttle goes up or
>comes down, I read about how just about every system is checked, removed,
>replaced, etc. I can understand a thorough checkout, and the fact that
>space travel is, to say the least, a risky business, but how much of what
>NASA does for turnaround would be considered unneccesary in 10-15 years
>(Provided the same shuttle design is still running).
> Few of us have a problem with a commercial plane ride in bad weather,
>yet we read that they can't even roll the shuttle to the pad because of rain!
>This also reminds me of just about every nut and fastener being traceable to
>who installed it, when, where it came from, etc.
Even commercial transport requires thorough checkout. There just aren't
any Public Affairs Offices keeping you informed on the maintenance being
done on the 747 you'll be flying later in the week.
The only time you hear about aircraft checkout and maintenance is when
someone FORGETS or slacks off, and then it's a sidebar to the body count.
The shuttle is more fragile than an airliner, of course, but that's
because we ask it to do much more violent things. An airliner's metal
skin may laugh at raindrops, but reentry heat would vaporize it.
My prediction is that we will never be allowed to stop checking spacecraft
with a fine toothed comb. What we can hope to do is make components
more reliable, so they require less swapping out; and to budget a stack
of hot spares for the cases where they still must be swapped, rather than
have to cannibalize other spacecraft.
--
Knowing *when* to optimize is just >>>/ Tom Neff
as important as knowing *how*. /<<< tn...@bfmny0.UU.NET
Henry Spencer
>Even commercial transport requires thorough checkout. There just aren't
>any Public Affairs Offices keeping you informed on the maintenance being
>done on the 747 you'll be flying later in the week.
That's mostly because the manpower involved in said maintenance is several
orders of magnitude smaller. 747 "thorough checkout" and NASA "thorough
checkout" are enormously different things. 747 maintenance crews do not
remove, examine, replace/refurbish, and re-install 5000 components on
each engine after every flight. NASA crews do exactly that for each SRB.
>My prediction is that we will never be allowed to stop checking spacecraft
>with a fine toothed comb...
Until we start designing them not to need fine-toothed-comb checkout,
this is trivially true.
--
A bit of tolerance is worth a | Henry Spencer at U of Toronto Zoology
megabyte of flaming. | uunet!attcan!utzoo!henry he...@zoo.toronto.edu
Tom Neff
>[I sez]
>>My prediction is that we will never be allowed to stop checking spacecraft
>>with a fine toothed comb...
>
>Until we start designing them not to need fine-toothed-comb checkout,
>this is trivially true.
Then my prediction AFTER THE SPENCER TRANSFORM, thank you very much, is
that it will never be practicable to design spacecraft that don't
require a fine toothed comb checkout. The only way I'm wrong on this is
if we drag full scale war into space, since the military ethic is (or
used to be) to build things that could take a beating, at the cost of $$
and efficiency. I would prefer not to be wrong for that reason. :-)
--
DEFINITION, n. statement of precise <\< Tom Neff
meaning of word etc. [F f L (DEFINE)] >\> tn...@bfmny0.UU.NET
Henry Spencer
>comes down, I read about how just about every system is checked, removed,
>replaced, etc. I can understand a thorough checkout, and the fact that
>space travel is, to say the least, a risky business, but how much of what
>NASA does for turnaround would be considered unneccesary in 10-15 years
>(Provided the same shuttle design is still running).
Probably not very much. The hardware simply is not designed for airline-type
operations, and NASA has no concept of how to operate that way anyway.
> As I said before, I agree that such stringent measures are required
>at our current level of knowledge with space travel...
Many people would debate this. The problem is not with knowledge or
technology, but with the way they are being applied by the people doing
launch systems right now. People like Max Hunter (designer of the Delta,
nee Thor) say quite firmly that you can't expect easily-reusable systems,
ever, from people who think of spacecraft in terms of missiles rather
than airliners.
Henry Spencer
>that it will never be practicable to design spacecraft that don't
Actually, there are two relevant questions here.
First, will NASA ever find it practicable to do so? I think we both
agree that the answer is no, although perhaps for different reasons. :-)
Second, will *anybody* ever find it practicable to do so? Here, Tom,
I'm afraid I have to continue to disagree. While I respect your opinions
on a number of things, when you say "no" and Max Hunter says "yes", I'm
afraid I believe him, not you. (For those who don't know who Hunter is,
the Delta launcher is a slightly souped-up Thor missile, and Hunter
designed the Thor... taking it from contract signing to operational
service in 3.5 years.)
If you want a sample of what Hunter is saying lately... The shuttle
system manages 6-8 launches a year, with hopes for somewhat more, at
a manpower level of 9000+ for three orbiters. Arguably airlines are
an unfair comparison, so let's compare to the SR-71: it too is an
advanced, kludgey, quirky beast that requires a lot of babying and
arguably has never really been "operational" in the normal sense.
"Any engineer who examines the situation would agree that very high
performance aircraft are every bit as high tech, tricky and complex
as space launchers, and likely more so. Fighting high-speed aerodynamic
forces in the atmosphere is *not* for the faint-of-heart. Space
publicists (and apologists), of course, would disagree..."
About 8 SR-71s fly over 400 flights per year with a total support
staff of 385 people.
Tom Neff
that don't require checking with a fine toothed comb after every flight
as the Shuttle does)
In article <1989Nov4.0...@utzoo.uucp> he...@utzoo.uucp (Henry Spencer) writes:
>First, will NASA ever find it practicable to do so? I think we both
>agree that the answer is no, although perhaps for different reasons. :-)
Or even for the same reasons. Personally I think if NASA found such a
design they would have the designer assassinated -- it runs counter to
everything NASA exists for.
>Second, will *anybody* ever find it practicable to do so? ...
[Max Hunter, who designed the Thor missile, says yes] ...
[Max points out that the Shuttle uses a zillion times more people/launch
than the kludgey, quirky, high tech SR-71]
* The Thor is not a spacecraft in the sense of the current discussion.
It was a wonderful vehicle and a masterpiece (I am sure) of design, but
it was a nonreusable ballistic missile. Care and maintenance BETWEEN
LAUNCHES was not a factor in design! I would be more overwhelmed to
read the comments of someone who worked on X-15 or the shuttle. To
paraphrase Hunter, going into space AND RETURNING and going again is
not for the faint of heart!
* Anyway his point seems to be that the Blackbird gets it done with
fewer people, NOT that the checking doesn't have to be done. I have no
problem with the assertion that we can recycle spacecraft a lot more
efficiently (although there is a limit to what can be done with the
current bird). Getting the man-hour numbers down is not the same as
"landing, gassing up and taking off" though. Every subsystem *must* be
checked. We just have to learn to do it at the flick of some switches
rather than via ruinously expensive hand labor.
HOW...@yalevm.ycc.yale.edu
>>My prediction is that we will never be allowed to stop checking spacecraft
>>with a fine toothed comb...
>
>Until we start designing them not to need fine-toothed-comb checkout,
>this is trivially true.
technology when we should be using *reliable* technology. Sorry to be
cliche, but how long do you think it would take for the Soviets to dump
a payload on a production Proton and boost it? And what are the odds
of failure?
I was reading an article in the Nov. Discover (hey, it was lying
around, I couldnt help it.. :-) about the space plane, which they said
would have lots of uses. Say the station needs an important part....
well, just fill er up with H2 and take off! No worries! They also
compared the expected turnover time of " a few hours, or maybe days"
with the "months" for the shuttle. I'll agree with months... but
wait, was this how it was planned? What was the original turnaround
for the shuttle expected to be... about a week, right? Does anyone
actually think that the NASP, using virtually untried technology, will
be able to be checked out and readied for flight in hours? Using
scramjets and weird cooling systems, no less...
Call me dubious.
Greg
David Schneider
>(For those who don't know who Hunter is,
>the Delta launcher is a slightly souped-up Thor missile, and Hunter
>designed the Thor... taking it from contract signing to operational
>service in 3.5 years.)
That's a good intro for my question.
I've been meaning to ask if anyone can point me at a convenient
family tree of US launchers, primarily the liquid-fueled variety.
I can still say "Redstone" and "Atlas", and I know some second stages
were originally first stages, but I can't make a coherent picture
of it.
Dave Schneider
Monday, Nov 13
Henry Spencer
>I've been meaning to ask if anyone can point me at a convenient
>family tree of US launchers, primarily the liquid-fueled variety.
Well, here's a first cut. There is actually not all that much branching
in the tree. I'm ignoring assorted trivia like sounding rockets.
Redstone, a tactical ballistic missile, with three small solid upper stages
became Jupiter-C and launched Explorer 1 and some others. (The "Jupiter-C"
terminology is because it was testing components for the Jupiter program,
and von Braun & Co. noticed that things marked "Jupiter" got higher priority
at the Cape than things marked "Redstone".)
Jupiter, an Army IRBM, acquired an upper stage or two and became the Juno
family of space launchers, which saw a little bit of use. Don't know much
about it. Long extinct.
Atlas, the first US ICBM, was used as a launcher all by itself for modest
low-orbit payloads, including Mercury. With the addition of the first US
liquid-hydrogen stage, the Centaur, it saw heavy use for low orbit, high
orbit, and planetary missions. Numerous variants have appeared over the
years, with a steady trend to longer tanks and hotter engines. An earlier
upper stage, the Agena, also saw use for modest planetary missions and
satellites, notably military ones, and was used for a docking target on
Gemini.
Titan II, the second Titan ICBM (Titan I, despite the similar name, was
an entirely different missile), also has seen use in various forms.
One variant of it (slightly longer tanks than the ICBM, I think) launched
Gemini. Both alone and with upper stages (notably Agena), it launched
quite a few missions. The last Titan-Agena flew only a few months ago.
Now that the Titan II ICBM force has finally been retired, the USAF is
reworking a bunch of them into medium launchers.
Titan III is a Titan II with two great big solid strap-ons. There were
a number of different versions, notably IIIC (general heavy-load USAF
booster), IIIM (meant to launch the cancelled MOL military space station),
34D (slightly upgraded IIIC), and IV (latest variant, longer SRBs and
other small improvements). Current US heavy expendable. Various upper
stages, notably Transtage (small liquid stage) and Centaur, were used.
Titan-Centaur was used for Voyager, among other things. The latest
versions now fly with the shuttle IUS or the intended-for-shuttle fat-
tank Centaur as an upper stage.
The USAF's Thor IRBM (which used some Atlas technology, notably engines)
was turned into a small launcher with the addition of a modest upper
stage. This went through a whole bunch of steadily-bigger versions,
with tanks getting longer and fatter, engines getting hotter, and solid
strapons (first 3, then 6, now 9, and they're getting longer and fatter
too) added. Somewhere along the way it was renamed Delta. The Japanese
H-1 is a Delta spinoff, incidentally, with a new liquid-hydrogen upper
stage (which McDonnell Douglas would like to buy back except it's not
for sale).
The Scout is practically the only one of the bunch that isn't a missile
derivative. Scout is four big sounding rockets piled up to make a very
small satellite launcher. It too has grown a little bit over time.
There were a vast number of proposed Saturn configurations, only three
of which ever became real.
The Saturn I had a first stage which was a massive cluster of Atlas/Thor
engines and Atlas and Redstone tankage, plus a small upper stage that
was sort of a fat Centaur with more engines. It was basically a dead
end, in retrospect of no importance except for technology development
for later Saturns.
The Saturn IB used a stretched souped-up Saturn I first stage, plus
the big S-IVB liquid-hydrogen upper stage of the Saturn V, for low-orbit
Apollo launches and some other odds and ends.
The Saturn V, despite the similarity in name, had nothing to do with the
Saturn I. Three all-new stages with all-new engines. Intended for
Apollo lunar missions, lunar bases, space stations, heavy planetary
probes, etc etc. 15 built; 13 used, 2 rusting lawn ornaments.
The Shuttle is another all-new launcher. Its SRBs are somewhat similar
to the Titan ones, but many details are different and they are bigger.
Nick Watkins
>That's a good intro for my question.
>I've been meaning to ask if anyone can point me at a convenient
>family tree of US launchers, primarily the liquid-fueled variety.
Best off the cuff references are
The Rocket by David Baker (Crown US, 1979 (?))
and
Missiles and Rockets by Kenneth Gatland (Blandford Press UK, 1976 (?)).
The appendices in the former may be all you need.
Also see Andrew Wilson's historical articles in old issues of
"Spaceflight"; and old editions of Jane's All The World's Aircraft (which
used to cover space).
>I can still say "Redstone" and "Atlas", and I know some second stages
>were originally first stages, but I can't make a coherent picture
>of it.
It isn't very coherent. Basically you have 7 families:
Redstone (Juno 1, Mercury Redstone, WRESAT)
Jupiter (Juno 2)
Scout (various models)
Thor (Delta, Thor Agena, Thor Burner 2, Thor LV 2F and various other
little used variants, new commercial Delta 2.)
Atlas (Atlas Centaur, Atlas Agena, Atlas Able, Atlas Burner 2, Mercury
Atlas D, reconditioned Atlas E and F ICBMs with or without upper
stages, also new commercial Atlas 1 and 2, an Atlas Centaur derivative.)
Titan (Gemini Titan II, Titan 3A, 3B Agena D, 3C, 3D, 3E Centaur, 34B,
34D, Titan II SLV, Titan IV, and new commercial Titan III, a 34D derivative.)
Saturn (I, IB, V)
These cover most variants but I'm bound to have missed some (I'm leaving
out very new developments e.g. Pegasus).
Nick
--
Nick Watkins, Space & Plasma Physics Group, School of Mathematical
& Physical Sciences, Univ. of Sussex, Brighton, E.Sussex, BN1 9QH, ENGLAND
JANET: ni...@syma.sussex.ac.uk BITNET: nickw%syma.sus...@uk.ac
Jonathan McDowell
> Titan II, ... The last Titan-Agena flew only a few months ago.
> Titan III is a Titan II with two great big solid strap-ons.
Minor correction: Agena flew on strapon-less Titan IIIB and Titan 34B, not on Titan II.
The distinction between II and III is not the presence of the strapons
but the fact that III was specifically designed for space missions.
> The USAF's Thor IRBM ....
> was turned into a small launcher with the addition of a modest upper
> stage.
You then talk about Delta, which was originally the name of a Thor upper stage;
but there was a whole other family of Thor-based launchers, the Thor Agena series,
which was the major launch vehicle of the 1960s.
-Jonathan McDowell
Nick Watkins
writes:
>Redstone, a tactical ballistic missile, with three small solid upper stages
>became Jupiter-C and launched Explorer 1 and some others.
Jupiter C with a live 4th stage was also known as Juno 1. On one
celebrated occasion Von Braun was directed to fill the 4th stage with
sand to avoid an orbital mission. Redstone was also used for suborbital
Mercury flights, including Shepard's and Grissom's. It was also the
basis of the Australian WRESAT one-off launch.
>Jupiter, an Army IRBM, acquired an upper stage or two and became the Juno
>family of space launchers, which saw a little bit of use. Don't know much
>about it. Long extinct.
Jupiter with the same upper stages as Jupiter C/Juno 1 was Juno 2. Juno 1 was
a deliberately confusing Von Braun name for a Redstone derivative, see
above. See Wilson's "The Eagle Has Wings" for more details.
>Atlas, the first US ICBM, was used as a launcher all by itself for modest
>low-orbit payloads, including Mercury. With the addition of the first US
>liquid-hydrogen stage, the Centaur, it saw heavy use for low orbit, high
>orbit, and planetary missions. Numerous variants have appeared over the
>years, with a steady trend to longer tanks and hotter engines. An earlier
>upper stage, the Agena, also saw use for modest planetary missions and
>satellites, notably military ones, and was used for a docking target on
>Gemini.
Atlas has been used with other upper stages, notably Burner 2 and the
shortlived Atlas Able. Atlas Centaur & Atlas Agena were the main ones though.
Atlas Agena lasted as late as 1977/78 for the final Rhyolite launches,
after which Pad 13 at KSC was dismantled. Atlas is still used alone for some
launches from Vandenberg, these are reconditioned Atlas E/F ICBMs so the
supply will dry up. Titan II SLV has taken over the job for the Navy
ocean surveillance satellites, while GPS satellites, which used to use
Atlas are now sent up on Delta 2 from the Cape. I think the NOAA polar
orbit weather satellites use these Atlas boosters also, as did NASA's
Seasat in 1978.
>Titan II, the second Titan ICBM (Titan I, despite the similar name, was
>an entirely different missile), also has seen use in various forms.
>One variant of it (slightly longer tanks than the ICBM, I think) launched
>Gemini. Both alone and with upper stages (notably Agena), it launched
>quite a few missions. The last Titan-Agena flew only a few months ago.
Strictly speaking the Titan Agena variants were part of the Titan III
family, i.e. the Titan 3B Agena D, and the 34B Agena. Has anybody ever seen
a photo of the latter? I think you'll find the last flight of a Titan
Agena was in 1987.
>Now that the Titan II ICBM force has finally been retired, the USAF is
>reworking a bunch of them into medium launchers.
Called the Titan II SLV. They have been launched twice so far. There is
a plan to produce a solid booster assisted version for an SDI related launch.
>Titan III is a Titan II with two great big solid strap-ons. There were
>a number of different versions, notably IIIC (general heavy-load USAF
>booster), IIIM (meant to launch the cancelled MOL military space station),
>34D (slightly upgraded IIIC)...
Add IIIA, a IIIC with no boosters, used for the first four tests. Also
IIID, a IIIC with no Transtage & with radio guidance used for Big Bird & KH11.
Titan Centaur was Titan IIIE. The 34D in its East coast version replaced
the IIIC and could be fitted with the IUS as well as the Transtage
though this was apparently only done once, in 1982, for a DSCS launch.
The West coast version replaced the Titan IIID.
>... and IV (latest variant, longer SRBs and other small improvements).
> Current US heavy expendable. Various upper
>stages, notably Transtage (small liquid stage) and Centaur, were used.
>Titan-Centaur was used for Voyager, among other things. The latest
>versions now fly with the shuttle IUS or the intended-for-shuttle fat-
>tank Centaur as an upper stage.
Titan 34D commercial variant ("Titan 3") and Titan IV are the only ones
remaining in use. See "Space" September/October 1989 for more details of
Titan IV.
Both are identifiable by their huge shrouds, commercial Titan's is made in
Europe, while Titan IV's allows it to carry an IUS or Centaur. They now
look very like the old Titan Centaur at first glance.
>The USAF's Thor IRBM (which used some Atlas technology, notably engines)
>was turned into a small launcher with the addition of a modest upper
>stage... Somewhere along the way it was renamed Delta.
Original launcher was called Thor Delta, as I'm sure you know, but
didn't say. Thor was also used with Agena, Burner 2 and in a few other
minor variants including the version used to launch the Block 5D USAF metsats
where the satellite also provided the upper stage and guidance for the
whole stack.
>The Japanese
>H-1 is a Delta spinoff, incidentally, with a new liquid-hydrogen upper
>stage (which McDonnell Douglas would like to buy back except it's not
>for sale).
I gather they have to buy Delta fuel (kerosene) from Japan also, as it
is no longer made in the US.
>The Scout is practically the only one of the bunch that isn't a missile
>derivative.
Granted the origins of Saturn, you can say THE only one.
Hope these additions are useful, and not a source of confusion,
Henry Spencer
>>The Japanese H-1 is a Delta spinoff...
>I gather they have to buy Delta fuel (kerosene) from Japan also, as it
>is no longer made in the US.
Depends on the variant of the main engine. The modern variants use
US-made fuel, but there are still one or two old engines that McD-D
wants to use up, and they've bought Japanese fuel for them.