ACRV - Capsules or spaceplanes

bitflip wrote:

that escape rocket over his head). The spaceplane represents several new
technology development efforts. I say build both for different reasons. Any
thoughts?

Build the capsule. The spaceplane is a complete waste, except as a welfare
program.

concept. Its possible to have a capsule tested and on the space station in
3-5 years. The capsule has zero new technology development, can hold 6-7

Sounds good to go for now. Then work on the space plane and do it right.

"bitflip" writes:
I say build both for different reasons. Any thoughts?

Yes. Don't bother with space planes at all. If a capsule looks
better now than an X-38 type of vehicle, why pursue one in the
future. What will magically make it better in the future?

Jeff
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The only way to do a "space plane" right is not to do one in the first
place. What will a reusable space plane, "done right" give you that a
reusable capsule won't?

Jeff

Thats a GREAT question. Just what are the advantages?

On Sun, 13 Jul 2003 21:48:48 -0500, "bitflip"
wrote:

A debate has been developing for the past 3 months, Apollo derived capsules
or a spaceplane. Astronauts have expressed good support for the capsule
concept. Its possible to have a capsule tested and on the space station in
3-5 years. The capsule has zero new technology development, can hold 6-7
people and even support a cargo variant.

A spaceplane could as well. See Space Shuttle.

A capsule has a zero zero escape
option if on an EELV (one astronaut told me he felt safe on a Soyuz with
that escape rocket over his head).

There's no particular reason that the crew cabin couldn't be seperable
from the rest of the airframe in a spaceplane. As long as you design
it that way from the beginning. See B-1, F-111.

The spaceplane represents several new
technology development efforts.

It does? What do we need for an OSP that we don't have today? Hell,
what do we need for an OSP that we didn't have 20 years ago?

Brian

jeff findley wrote

"bitflip" writes:

I say build both for different reasons. Any thoughts?

Yes. Don't bother with space planes at all. If a capsule looks
better now than an X-38 type of vehicle, why pursue one in the
future. What will magically make it better in the future?

I also think that for delivery and return of people from orbit
capsules are the obvious way to go for now. We know how to do
capsules, and, if creeping technophilia is firmly suppressed,
they could be done reasonably quickly, cheaply, and at relatively
little developmental or operational risk. It would be nice if
they were reusable, but that wouldn't be strictly necessary.

No harm in putting "space planes" -- lifting bodies or whatever --
into a modestly funded research program. Some need might appear
in the future, and doubtless interesting data could be collected
in the meantime.

Why not have individual escape capsules like the B-57 had?

(Hallerb) writes:

The only way to do a "space plane" right is not to do one in the first
place. What will a reusable space plane, "done right" give you that a
reusable capsule won't?

Thats a GREAT question. Just what are the advantages?

That's my point, the advantages of a resuable space plane over a
reusable semi-ballistic capsule are few and not worth the extra cost,
IMHO.

One could argue that the space plane has more cross range, but his
argument is suspect. Given the same mass as a space plane, it's
possible to build a smaller, lighter capsule and add cross range as
more fuel for the deorbit engine.

One could argue that the space plane can perform lower G re-entries,
but what's the advantage here? The current CRV is Soyuz, which seems
to be good enough for NASA, for now.

Landing on a runway is "cool", but other than that, what's the
advantage? NASA already has recovery ships for the SRB's and Apollo
capsules routinely landed very close to their predicted locations.
Land recovery (just not on a runway) is a possibility too. Stick an
X-38 style parafoil on a capsule and you could land just about
anywhere you wanted.

Jeff
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Eric Pederson deZ to respond writes:

This is a case where size does matter. For a small vehicle with a
round trip payload similar to that of a mini-van, a capsule is likely
the right answer. For larger man-tended one-way payloads, a capsule
on top of a cargo stage would work. If you really want large return
payloads, active landing systems (wings or motors) enter the picture
and things get more complicated.

First, the return of large payloads is a capability that is used on
the shuttle (e.g. Spacelab up and down flights), but now that ISS is
in orbit, I'd think that your largest downmass would be an ISS rack.
You can design a capsule big enough to return lots of racks (think
Saturn IVB diameter capsule).

Second, active landing systems need not have really large wings or
resemble a "space plane". DC-X landed without parachutes, but did not
resemble a "space plane". It looked more like a super stretched out
semi-ballistic capsule to me.

Jeff
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Hmm, I am not a big fan of that CTV, be it capsule or Plane. But my I wonder
why we just dont use the old Dyna- Soar- design?
It is already there (has been for 40 years) and reminds me a lot of that new
spaceplane in all aspects...
I have to shake my head thinking about NASA redoing something that the
Airforce wanted to do 40 years ago (and that was cancelled back then) and
then needing 12 billion dollars and 8 years for that...
I mean the airforce did not need 8 years to develop the Dyna Soar and at
that time they had to start from scratch for every single part of it,
whereas nowadays we have got much more experience (at least thats what one
would believe)
CU
Elmar

"bitflip" schrieb im Newsbeitrag
...
A debate has been developing for the past 3 months, Apollo derived
capsules
or a spaceplane. Astronauts have expressed good support for the capsule
concept. Its possible to have a capsule tested and on the space station in
3-5 years. The capsule has zero new technology development, can hold 6-7
people and even support a cargo variant. A capsule has a zero zero escape
option if on an EELV (one astronaut told me he felt safe on a Soyuz with
that escape rocket over his head). The spaceplane represents several new
technology development efforts. I say build both for different reasons.
Any
thoughts?