Shuttle-C Encore - Just Say No!

Sorry, no. If the OSP goes to the moon even once, that means that
every single mission has to pay the penalty of an overweight
heatshield and the extra systems needed to connect it to the 'other
part'.


And your saying that the cost savings achieved in shaving off some of the heat
sheild so that its just barely adequate for a low orbit reentry are enough to
justify late developing a separate vehicle for high orbit operations. Do you
really think the costs of the Apollo Command Module was instrumental in
cancelling the Skylab program, was that the primary reason that Skylab was
cancelled. No one thought it worth while to develop a less robust command
module for the Apollo/Soyuz mission in 1975. Why not? If what your saying is
true, then an entirely new vehicle should have been developed to fulfill the
orbital taxi mission for the Skylab program, and the Apollo/Soyuz mission. Also
some of the pre-lunar landing Apollo missions never left lunar orbit, yet they
used the Apollo command module rather than a slimmed down version capable only
of reentry from Low Earth Orbit. Apparently the engineers and directors of the
Apollo program couldn't find justification to develop two separate versions of
the Apollo Command Module, one for low orbit and the other for cis-lunar
operations.

Tom

(TKalbfus) wrote:

And your saying that the cost savings achieved in shaving off some of the heat
sheild so that its just barely adequate for a low orbit reentry are enough to
justify late developing a separate vehicle for high orbit operations.

I'm saying no justification beyond masturbatory fantasies exists for
high orbit operations.

D.
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On 2003-11-17, Brian Thorn wrote:
On Sun, 16 Nov 2003 21:07:22 GMT, "Dholmes"
wrote:

Shuttle-Z was not in-line and was proposed for payloads of 120 tons.

I am not familiar with that proposal the closest I know of is Ares.

Shuttle-Z was evidently the immediate predecessor of Ares proposals.

Can you point me towards some design info on the Shuttle Z?

No good references online. Zubrin seems to refer to it frequently, but
I can't find anything specific online. Jenkins has a chapter about it
(and Shuttle-C) in an earlier edition of his _Space Shuttle_ book.

Hmm. Mark Wade's Encylopedia Astronautica _used_ to have an entry on it
according to this reply from Kim Keller to a question I asked a few years
ago:

http://groups.google.com/groups?hl=e...ndspring.co m

Unfortunatley, Encylopedia Astronautica (www.astronautic.com) doesn't
seem to have it any more (either that, or I couldn't find it.) Mind you,
I don't recall it having huge amounts of tech detail.


IIRC the 1997 Mars Reference Mission (still avaliable at
http://exploration.jsc.nasa.gov/marsref/contents.html also mentioned
the "Magnum" launch vehicle, but its been a while, and I've lost my
local copy [and its big...]

Checkout http://ares.jsc.nasa.gov/HumanExplor...ddendum/A3.htm for a few details on Magnum.

In short, Shuttle-Z was an SEI proposal that died with SEI. It was a
behemoth with a cargo section/upper stage where the Shuttle-C cargo
module or Orbiter would go, but it was much larger.

And Ares was bigger, and "Magnum" bigger than that IIRC (and none
got off the paper, let alone off the launch pad...)

Hope this is of some interest, sorry its not all the stuff I remember
reading when I looked into it in 1998.


All the Best

Iain

I'm saying no justification beyond masturbatory fantasies exists for
high orbit operations.


How about the repair of communications satellites? Trips to the Moon? Trips to
an Earth Moon L1 space station? These are valid reasons to build a high orbit
capable OSP.

Tom

"Jorge R. Frank" wrote in message ...
(Tom Merkle) wrote in
om:

2. Environmental control--this is the most different requirement. OSP
will be required to provide life support for at least one day for 6-8
astronauts.

Incorrect. OSP *as a system* is required to support a crew of *four*. And
the bidders are allowed to do so with *multiple* spacecraft, so a pair of
two-man capsules would technically meet the requirement.
I checked the actual req'ts.
You're right--technically. The OSP Level 1 req'ts are bounded at "no
less than four." However, the Level 2 req'ts actually specify three
days life support between launch and ISS rendezvous. That's 12 man
days, even greater than I had estimated.
Also, although the requirements do not specify a single vehicle
capable of transporting 4 astronauts, the requirements are adamant
that the OSP system be aimed towards developing a future
capability--which means that designs that favor future expandability
will be favored. I suspect that any small designs requiring multiple
vehicles to move four astronauts will appear to be unnecessarily
complex, unwieldy, and unexpandable to be deemed as useful, especially
given the "greater orbital manueverability than shuttle" requirement.
But I could be wrong.

Tom Merkle

(TKalbfus) wrote in message ...
It is impossible
to make a shuttle, delta wing, or x-37 shaped OSP do the same thing.
Loads in two directions, higher heating loads on radiative heat
transfer surfaces and larger surface area make this entirely
impossible.

Impossible? That's a challenge, let me see if I can figure out away. One could,
for instance, embed a glider inside the capsule.

I said it was impossible to easily upgrade a "shuttle, deltawing, or
x-37 shaped OSP" to return directly from lunar orbit. I didn't say it
was impossible to make a capsule shaped vehicle into a glider.

Tom Merkle

The capsule lets the glider
survive reentry and when its velocity has slowed sufficiently, the capsule pops
open and releases the glider, which extends its wings and lands on a runway.
Another way is to have the capsule deploy a parawing instead of a parachute,
have it eject the heat shield underneath to uncover a set of landing gear. The
capsule then glides in for a runway landing.

On 18 Nov 2003 15:06:09 GMT, in a place far, far away,
(TKalbfus) made the phosphor on my monitor glow in
such a way as to indicate that:

How do you know?

Because unlike you, I have experience and knowledge in such matters.


And you can read the minds of the Chinese without asking them?

It doesn't require mind reading.

--
simberg.interglobal.org * 310 372-7963 (CA) 307 739-1296 (Jackson Hole)
interglobal space lines * 307 733-1715 (Fax) http://www.interglobal.org

"Extraordinary launch vehicles require extraordinary markets..."
Swap the first . and @ and throw out the ".trash" to email me.
Here's my email address for autospammers:

"Tom Merkle" wrote in message
om...
I suspect that any small designs requiring multiple
vehicles to move four astronauts will appear to be unnecessarily
complex, unwieldy, and unexpandable to be deemed as useful, especially
given the "greater orbital manueverability than shuttle" requirement.

In practice, none of the proposals are sized smaller than a crew of four,
with the capability of flying anywhere from 0-4 crew with varying amounts of
cargo.

-Kim-

In article t,
Joseph Oberlander wrote:
Well, there IS a problem with the current Shuttles. The original
design called for titanium construction.

No, the question of aluminum vs. titanium was left open. When it came
time to make it, the engineering was pretty much a wash: titanium needed
less protection (and hence less aggressive tile technology) but was much
harder to work with, and costs looked about equal.

One of our Presidents
at the time said all the titanium needed to go towards our war efforts
in Vietnam...

No, the deciding factor was the USAF's fear of titanium shortages which
might affect its (post-Vietnam) programs like the F-15. Such technical
details rarely get Presidential attention.

Hence the need for the extra solid fuel boosters

No, titanium doesn't make *that* big a difference. The system would look
essentially identical, and perform essentially identically, if the choice
had gone to titanium. The choice of structural material was part of the
detail design of the orbiter, long after the basic system architecture
was decided.

...It also
was supposed to be liquid fuel only, causing a LOT less stress on the
design and payload. Oh - no O-rings to fail, either.

None of which had anything to do with titanium. The use of solid boosters
was dictated specifically by OMB's $1G/yr cap on the shuttle development
budget. Nothing else fit within that.

Also, it's JUST possible the shuttle might have survived re-entry
if it was titanium, as it has a MUCH higher melting poin...

No, I'm afraid not. Titanium actually is not significantly better at
handling a case like that. Yes, it's good to higher temperatures, but it
is also much less thermally conductive, and has much lower heat capacity.
So when exposed to a localized source of intense heat, it heats up much
more quickly, and so it fails about as rapidly.
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |

Henry Spencer wrote:
Joseph Oberlander wrote:
Well, there IS a problem with the current Shuttles. The original
design called for titanium construction.
[...]

Also, it's JUST possible the shuttle might have survived re-entry
if it was titanium, as it has a MUCH higher melting poin...

No, I'm afraid not. Titanium actually is not significantly better at
handling a case like that. Yes, it's good to higher temperatures, but it
is also much less thermally conductive, and has much lower heat capacity.
So when exposed to a localized source of intense heat, it heats up much
more quickly, and so it fails about as rapidly.

I'm not so sure about that, in regards to Columbia;
the spot with the most intense heating, at the leading
edge, was cut through but apparently not where
the breakup started. A titanium Columbia would probably
have lasted longer without shedding pieces, the gas getting
past the leading edge might well not have been hot enough
to destroy other structures. The question of whether there
would have been a later catastrophic failure due either to
the leading edge failing more catastrophically or total heat
load into the wing box would require more analysis.

What is fairly clear to me, though, is that the total energy
coming in was enough to destroy or severely damage all the wiring
and hydraulics and the landing gear and such, even if the wing
structure wasn't destroyed. Even assuming the most optimistic
structural performance from the basic airframe, there was little
to no chance of the vehicle getting back on the ground intact.
Control systems and the landing gear were very seriously
affected by the hot gases in the wing, it might not even
have been controllable enough to safely parachute out once
it reached subsonic gliding. It's quite possible that the
aerodyamic controls were damaged enough that it would have
been uncontrollable even sooner than that and tumbled
and broken up.


-george william herbert