Alternate Access to Space - HMX Presentation Online
Clark S. Lindsey
that HMX made in 2000 in its successful bid for an "Alternate Access
to Space" design study contract. See www.hmx.com
In the HMX approach, their reusable XV capsule would ride a Titan II
to deliver up to 4000lbs of cargo to the ISS. With funding starting in
2001, first flight of a light version (300-1000lbs cargo) would have
flown this year.
The file has a new preface page in which Gary talks about the
background of the AAS program and why it will not be continued.
I have a copy of the preface at
www.hobbyspace.com/Links/RLVNews.html
- Clark
Peter Kelly
vehicle overseas next to impossible, but that XV capsule would
probably fit nicely on a Tsyklon or Dnepr rocket.
GCHudson
We did look at importing Tsyklons for launch from US sites, and this would
still be a possibility, but absent a contract to actually sell XV services for
ISS resupply, we didn't take it any further than preliminary inquires.
Gary C Hudson
HMX
George William Herbert
in discussing why your proposed alternate access
capsule was done in the cylinder with faired base
design approach rather than the "traditional"
blunt cone.
There is plenty of design work on capsules of the
shape you used... any number of ICBM RVs, of course,
plus the little Russian payload return capsules
which have ICBM RV design heritage as I understand it.
But it's not common in larger capsules.
I am curious for two specific reasons.
One, the fraction of total aerobraking heat
transferred into the vehicle is far higher with
such shapes than blunt cones, so the thermal
protective problem is that much harder overall.
Two, you seem to have a higher ballistic
coeficient with that general layout.
The issues and design decisions that shape raises,
in the form of the opening nose for the hatch,
the people facing forwards, etc., also seemed
sort of an interesting set of complications.
-george william herbert
gher...@retro.com
GCHudson
Main reasons:
1) The AAS requirements were to match Progress spacecraft volumes. We could
only do that with a relatively longer pressurized cylinder vs. a more
Apollo-like shape for a given diameter that was fixed.
2) We wanted more post-atmospheric entry interface maneuverability than a
ballistic capsule could give to offset winds and targeting errors, since we
really wanted to hit a very small CEP.
3) We liked the lower entry g from this design, about a third to half of the
ballistic variants.
4) In aborts, we didn't have to turn the vehicle around in order to enter/land.
It was stable going forward without any additional aerosurfaces or devices.
Gary C Hudson
HMX
Peter Kelly
The U.S. Government gets tired of footing most of the bill for the
ISS. They realize that they have to provide an incentive for other
countries to carry more of the load. To this end, they suspend most
technology transfer restrictions for active ISS partners and actually
encourage them to build cargo and crew transfer vehicles.
Under those circumstances, the XV capsule might fly on a Tsyklon from
Alcantara instead of Wallops Island.
lisa simpson
=====================================
Isn't the cylinder with a faired base the exact design of the
Kistler 2nd stage? The Kistler people seem confidant that their
design will work but I wonder:
(a) Is the thermal protection soecially difficult and expensive, and
(b) Are the g-forces especially large?
>
>
GCHudson
>Isn't the cylinder with a faired base the exact design of the
>Kistler 2nd stage? The Kistler people seem confidant that their
>design will work but I wonder:
>
>(a) Is the thermal protection soecially difficult and expensive, and
>(b) Are the g-forces especially large?
It is indeed very similar; in fact, refinements made after the version in the
presentation I posted even flattened the nose a bit and made it more similar.
But engineering will often drive designers into very similar solutions.
(Consider Boeing, MDAC and Airbus transports, for example.) The basic shape is
around fifty years old, and was first used for ICBM reentry vehicles. Later,
the Soviets adopted it for a recovery capsule that was used on Mir.
As for your other question, the thermal protection problem is largely the same
for lifting and ballistic designs. Each option has advantages, but in both
cases, one must use fairly similar materials. Advanced tiles such as SIRCA and
AETB are preferred for the XV, and we'd have used them over the entire body
except the aft end. Even paying NASA prices for these materials and
installation, the cost would have been only about a million dollars per
vehicle, since the XV is about 20 ft long.
Regarding reentry gee, since the XV flies at a moderate angle of attack, the
L/D of the body is over 0.8 and the gees are under 2, very similar to the
Shuttle Orbiter or X-38 and quite a bit lower than ballistic entry.
Gary C Hudson
HMX
jeff findley
>
> Gary Hudson has posted a copy (5.5MB pdf) of the original presentation
> that HMX made in 2000 in its successful bid for an "Alternate Access
> to Space" design study contract. See www.hmx.com
Wow! This looks pretty cool. It would seem that such a vehicle might
have even been useful for Jim O.'s "care package" to send to a shuttle
in distress. If the shuttle is equipped with an APAS docking
mechanism (carried on all ISS flights), this would have eliminated the
risky EVA in order to catch the care package. Failing that, I'd think
Gary could come up with a few places to bolt on grapple fixtures and
hand holds.
This thing is sounding a lot like it could eventually meet CRV and OSP
requirements, given a bit more development past the Alternative Access
to Space requirements. Even without additional development, it looks
like a US made Progress with a payload return capability. That, in
and of itself, is pretty cool.
Wings, we don't need no stinking wings! :-)
Jeff
--
Remove "no" and "spam" from email address to reply.
If it says "This is not spam!", it's surely a lie.
GCHudson
A subsequent version of the XV indeed does have a CBM and grapple fixture for
RMS berthing vs. APAS docking. The CBM is somewhat lighter and actually allows
the Cg of the XV to be farther forward, improving overall reentry performance
and moderating entry g. It also allows payloads with larger dimensions (such
as an ISS rack) to be moved through the hatch.
By the way, the XV with the four place crew seats and abort motors meets all
Level I OSP requirements as currently published by NASA a few weeks ago.
Gary C Hudson
HMX
Scott Lowther
> By the way, the XV with the four place crew seats and abort motors meets all
> Level I OSP requirements as currently published by NASA a few weeks ago.
Are you going after that?
--
Scott Lowther, Engineer
"Any statement by Edward Wright that starts with 'You seem to think
that...' is wrong. Always. It's a law of Usenet, like Godwin's."
- Jorge R. Frank, 11 Nov 2002
GCHudson
>
>> By the way, the XV with the four place crew seats and abort motors meets all
>> Level I OSP requirements as currently published by NASA a few weeks ago.
>
>Are you going after that?
>
No, I've had enough of NASA's duplicity. Changing the rules in the middle of
procurements, inept management and resistance to innovation...I don't propose
to waste any more money on a fruitless attempt to solve their problems.
Gary C Hudson
HMX
jeff findley
> No, I've had enough of NASA's duplicity. Changing the rules in the middle of
> procurements, inept management and resistance to innovation...I don't propose
> to waste any more money on a fruitless attempt to solve their problems.
This is a pity, not because you're not going to try, but because I'm
sure you wouldn't have a chance of getting the contract. This is yet
another piece of evidence that NASA is part of the problem (expensive
manned access to space). It's sad, really.
A big part of this seems to be NASA's obsession with wings and runways
for vehicles that shouldn't need them. Such an obsession only serves
to drive up costs.
Of course, this is only one of many of NASA's obsessions when it comes
to manned access to space.
Michael Kent
>> GCHudson wrote:
>>> By the way, the XV with the four place crew seats and abort motors meets all
>>> Level I OSP requirements as currently published by NASA a few weeks ago.
>>Are you going after that?
>>Scott Lowther, Engineer
> No, I've had enough of NASA's duplicity. Changing the rules in the middle of
> procurements, inept management and resistance to innovation...I don't propose
> to waste any more money on a fruitless attempt to solve their problems.
Would you be willing to license out the design to someone willing to make
a go of it?
Mike
-----
Michael Kent Apple II Forever!!
St. Peters, MO
mic...@remove.this.syndicomm.com