Thomas Frieling in Spaceflight

Well since I wrote the op-ed piece I'll add to this discussion.

1) Yes you can reuse Apollo type Command Modules.

Remember NASA launched Gemini 2, then gave it to the USAF who carved a
hatch in its heat shield, then re-launched it on the first and only
MOL flight. It was recovered in good shape and I believe is still on
display at the USAF Museum at the Cape.

But do you want to reuse the CM? I doubt it. For one thing if you, by
some miracle, got Congress to fund Apollo Redux, the contractor will
build five or ten, then shut the production line down. Then you start
losing them over time and you're in the same state NASA is in today
after losing 40% of its Shuttle fleet in two decades of flight: the
other side of the coin of reusability is "losability." Much better to
have the production lines open.

If NASA keeps flying Shuttles, some day they will run out of Shuttles.
Russia, on the other hand, just keeps building Soyuzes. We should have
followed their model: Even though they built a Shuttle, they never
discarded their Soyuz technology. If the US had kept Apollo CSM/Saturn
1B technology, we'd be a lot better off today than we are, waiting for
the Shuttle to return to flight.

Is it cost effective to reuse a CM? Who knows? But note that NASA goes
to a lot of trouble to recover and reuse the Shuttle SRBs even though
studies have determined it would be cheaper to throw them away.

I submit that NASA is chasing a chimera with reusability and would be
better off if it gave up on that notion.

2) You don't need Carrier Task Groups deployed for contingency
landings Even if your flying an Apollo type CSM. Does Russia deploy
Naval vessels for Soyuz? Heck no. You solve the contingency landing
zone problem by giving the craft sufficient on-orbit loiter time to
hit any landing zone. I prefer Kansas, or Edwards, but you also have
the vast steppes of Russia (where more than a few manned missions have
ended, right?) or even the Australian Outback if you needed it.

3) And you don't even need all that much open space. Apollo did have
some, albeit modest, cross range capability, since its center of
gravity was offset. Enough to avoid bad terrain on landing is all you
need. Plus, Apollo landings were very accurate. So land landings are
not a particular challenge.

4) Proponets of OSP "wings and wheels" approaches like to tout the
gentle low g reentry, supposedly so injured crewman will not suffer
adverse effects. But Apollo LEO reentries only pulled a little more
than three Gs max. I submit if a cremember is too ill to manage 3 gs,
he probably is beyond help.

And the one major advantage of reviving the manufacture of Apollo CM
vehicles is it opens the possibility of going back to the moon. You'll
never be able to justify the payload hit you'd suffer by hauling wings
and wheels all the way to the moon where they are of absolutely no
use. But once again having a CSM, you could at least entertain the
notion of going back.

Bottom line is: The next Shuttle disaster will be the last one. I am
sure the political fallout of losing another orbiter will surely end
the program.

So does NASA roll the dice every time it flies a Shuttle, hoping it
will return in one piece? Or does it get on with the task of replacing
it? If NASA does lose another Shuttle before a replacement is
operational, it will likely mean the end of US manned spaceflight.

As I said in the op-ed piece: Use the Shuttles to finish Space
Station construction, then retire the fleet. An updated Apollo CSM
then takes over crew rotation and an unmanned cargo carrier--a Jumbo
Progress vehicle--takes over logistics for resupply.

Then back to the moon....

"Phil A. Buster" wrote in message ...
"Michael Gallagher" wrote in message
...
[carbon copy of this message being e-mailed to the man himself]

Hi, All..

Saw Thomas Frieling's piece in Spaceflight. Very nice!

No strong feelings either way on whether the shuttle should be ultimately
replaced by either a manned capsule or a small spaceplane, but this brings
up a question I've had in mind for a long time:

Would it be possible to build a reusable CAPSULE? Obviously, it would be
launched on an ELV and still have a disposable SM, but why not build a
series of capsules that can be used repeatedly and save a little money?
The
reusability concept must have some validity to it!


It is certainly possible. The bigger question is whether it is cost
effective. According to a number of articles I've seen over the years, NASA
found that returned Apollo capsules were in surprisingly good condition, and
actually did give some thought to reuse. It was not pursued because of the
limited scope of the program and the adequate number of capsules
manufactured and available at the time. I have occasionally wondered if
Russia reuses any Soyuz components. They don't as far as I know, but I
have never seen it discussed one way or the other. One would think that a
certain amount of hardware (e.g. radios and the like) should be readily
reusable, regardless of the bigger issue of the capsule itself.

(Derek Lyons) writes:

Yes you are. Apollo was *intended* as a general purpose orbiter, but
it's design was hardly begun before it's mission, and design, were
shifted to being the command craft for the lunar mission.

Especially the SM. As I said, the SM is grossly oversized for the
types of LEO missions that NASA needs to perform.

http://www.astronautix.com/craft/apolocsm.htm

The SM's propellant load was 18,413 kg while its overall mass was
24,523 kg. The maneuver system delta v was 2,804 m/s. To most, this
figure may be meaningless, so for comparison, let's look at the
shuttle:

http://www.astronautix.com/craft/endavour.htm

Endeavour's delta v is listed as 700 m/s. That puts the CSM's delta v
at 4x that of the shuttle. I'm not sure what orbit insertion costs in
terms of delta v, but that's a figure one could arguably charge
against the "launch vehicle", which you won't have for a CRV/CTV if
you assume that the launch vehicle puts it completely in orbit.

http://www.astronautix.com/craft/soyuztma.htm

One more data point. The Soyuz TMA has a listed delta v of 390 m/s,
which is a bit more than 1/2 that of Endeavour and less than 1/7 that
of the Apollo CSM.

Jeff
--
Remove "no" and "spam" from email address to reply.
If it says "This is not spam!", it's surely a lie.

jeff findley wrote:
One more data point. The Soyuz TMA has a listed delta v of 390 m/s,
which is a bit more than 1/2 that of Endeavour and less than 1/7 that
of the Apollo CSM.

That may be a product of Soyuz's role as a dedicated taxi as opposed
to the Shuttle's partial role as a general purpose orbiter. The
Shuttle's listed delta-V may be misleading if it's at the orbiters
empty weight. Unlike Soyuz and Apollo, the Shuttle's payload varies
greatly and is an appreciable fraction of the total mass.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

In article ,
Derek Lyons wrote:
Your memory fails. Gemini briefly was intended to come down on land
(under a parawing), but Apollo was targeted for a water landing from
the start.

Nope. Not if you go back to the very start. The original Apollo specs
called for land touchdown in the continental US... not just for a nominal
flight, but for most abort cases as well (which was seriously hard).
Significant work was done on land touchdown before the requirement was
relaxed; you can find early Apollo papers on things like braking rockets
and landing-gear design.

(The *reason* for this requirement was the same as the reason why the
original specs called for totally autonomous navigation with no ground
assistance at all, not even a voice link: Cold War security jitters.)

Again, I ma working from memory, each Apollo capsule could have bee
flown up to five times...

Your memory fails. There never was any such thing considered.

Re-use of Apollo capsules was definitely *considered*, although by the
time hardware was actually flying, the idea had gone very much to the back
burner. Even so, the flight program did include one or two small test
objectives related to re-use.

Strongly, being heated to several thousand degrees before taking a sal****er
dunk did nothing for the capsules reusability.

Your knowledge fails. The interior of the capsule is exposed to
neither great heat, nor sal****er. The heatshield, which is so
exposed, would have to be replaced each time regardless of landing
mode.

Correct. As witness the successful reflight of one unmanned Gemini
capsule.

One of the primary arguments against a capsule is the need to mount a full
scale search and rescue effort every time one lands.

Your knowledge fails. With few exceptions the capsules came down in
the intended area, and neither search nor rescue was required.

Indeed, the landing precision was good enough that an operational system
could have landed just offshore, or even in a major lake, which would have
needed much less nautical infrastructure.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

In article ,
Brian Thorn wrote:
I wasn't talking about the payload, I'm talking about the orbital
maneuvering system, power, long-duration life support, and fuel that
the Service Module carries. They're heavy and expensive, and they're
thrown away with all of the capsule concepts...

No, wrong. See the BAe Multi-Role Capsule papers in the Feb 1989 issue of
JBIS, for example.

The obsession with adding expendable service modules to reusable capsules
is the result of trying to make the capsule itself as small as possible.
But making the capsule bigger really costs very little, given adequate
launcher diameter, and it can ease many design problems.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

In article ,
Derek Lyons wrote:
Handwaving away the shock problems inherent in a land touch down, no
they are not a particular challenge. Modifying the Apollo capsule so
that it can tolerate the shock is a very different matter.

This is actually quite straightforward to solve, if you are willing to
postulate a new design which exploits the greater capsule size possible.
On close examination, the hard part of a touchdown without some sort of
terminal velocity reduction (braking rockets, parafoil flare maneuver,
whatever) is trying to reduce the velocity to zero with a very short
shock-absorber stroke.

But there is *no reason* why the stroke has to be so short! Make the
outer (aerodynamic) hull substantially larger than the inner (pressure)
hull, so there is room for a long-stroke shock-absorber system in between.
If you have the extra size -- quite feasible, for an EELV launch -- then
you just need a chief designer who is willing to dig in his heels and
insist that the empty space within the outer hull will *remain* empty, and
will *not* fill up with equipment/cargo/etc. just because it's there.

And that's assuming you're still using Apollo-style parachute descent,
rather than interesting alternatives like rotor landing, jet lift,
deploying a hot-air balloon rather than a parachute, etc.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

In article ,
Brian Thorn wrote:
And keep in mind... a capsule is going to be lighter for the same
capabilities, as it doesn't have all those dead weight wings etc.

Instead, it will have to have a honkin' big parachute/airfoil which
had better deploy just right.

Capsule designs routinely provide redundancy in parachutes. (Try doing
that with wings. :-))

Even then, you might still need a retro
rocket to make landing bearable for the crew.

Not if you use a gliding parachute with a flare maneuver, or simply make
the capsule big enough for a decent shock-absorber stroke.

And how big a capsule can they fit on top of a Delta or Atlas before
they start getting into aerodynamic problems that make wings look
easy?

Rather bigger than the winged vehicle which can go up on the same launcher
without incurring much worse aerodynamic problems.
--
MOST launched 1015 EDT 30 June, separated 1046, | Henry Spencer
first ground-station pass 1651, all nominal! |

(Henry Spencer) wrote in message ...
Flight vehicles should not be thought of as permanent assets to be
passed on to your grandchildren.

The B-52 scampers around this proclomation by being passed down
to great-grandchildren and great-great-grandchildren instead :-).

Tim.

Henry Spencer wrote:

In article ,
Derek Lyons wrote:
Handwaving away the shock problems inherent in a land touch down, no
they are not a particular challenge. Modifying the Apollo capsule so
that it can tolerate the shock is a very different matter.

This is actually quite straightforward to solve, if you are willing to
postulate a new design which exploits the greater capsule size possible.
On close examination, the hard part of a touchdown without some sort of
terminal velocity reduction (braking rockets, parafoil flare maneuver,
whatever) is trying to reduce the velocity to zero with a very short
shock-absorber stroke.

But there is *no reason* why the stroke has to be so short! Make the
outer (aerodynamic) hull substantially larger than the inner (pressure)
hull, so there is room for a long-stroke shock-absorber system in between.
If you have the extra size -- quite feasible, for an EELV launch -- then
you just need a chief designer who is willing to dig in his heels and
insist that the empty space within the outer hull will *remain* empty, and
will *not* fill up with equipment/cargo/etc. just because it's there.

And split the problem into two: stroke in landing legs, followed by stroke in the
couches. A combined three or four meters will make landings feel almost cushy
:_

On or about Wed, 27 Aug 2003 03:12:52 GMT, Greg D. Moore (Strider)
made the sensational claim that:
Umm, I'm not sure, but I think putting the bathroom outside the pressure
hull might not go over well. :-)

Bah. I've had to go worse places.
--
This is a siggy | To E-mail, do note | This space is for rent
It's properly formatted | who you mean to reply-to | Inquire within if you
No person, none, care | and it will reach me | Would like your ad here