"Peter Stickney" wrote in message
...

Sorry for taking so long, but I was lining up some ducks...

(snip)

I can't think of any advantages to the STS's layout. What did you mean
here?

Just off the top of my head - better alignment of teh Main Engine's
thrust lines with the CG of the entire stack. This gives you less
problems with control, and more tolerance of off-normal
conditions. (Such as losing a Main Engine - it's happened once on STS)

The Buran didn't have Main Engines on the Shuttle. One of its major
advantages to me, not having all that plumbing to the ET...

Concentration of teh Guidance & COntrol systems in a single,
integrated system, rather than having two independant systems that
have to try to talk to each other. Keeping the expensive, reusable
bits in one place, and throwing away the cheap stuff. (As it turns
out, this didn't work out as well as originally expected - rather than
a clear advantage wrt reusing STS SSMEs vs. the Energia's cheaper,
(but still not cheap) expendables, it seems to be pretty much of a
wash.

Exactly. Although the original concept of the STS being a reuseable vehicle
was excellent, the compromises made during the design process (many at the
behest of the DoD) negated them almost entirely.


Well, the Astronauts never flew it. That tells you something.

Buran: 1 unmanned flight, total success.

Not a total success - teh flight article was structurally damaged on
re-entry. I don't know if repair was possible.

That is news to me. See for example:

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

Mark Wade quote excized

Could you be mistaken? Or is this fairly new info? If the latter, I
would be
interested in knowing your source.

No, I'm not mistaken. It's not new info, although teh (then) Soviets
weren't too big on publishing it. There are various sources, but the
best place to go, if you can read Russian, is the Official Buran
site:
Http://www.buran.ru/

Even if you don't read Russian, here are some post-flight images of
Buran:

http://www.buran.ru/images/jpg/posle01.jpg
http://www.buran.ru/images/jpg/posle02.jpg
http://www.buran.ru/images/jpg/posle03.jpg
http://www.buran.ru/images/jpg/posle04.jpg
http://www.buran.ru/images/jpg/posle05.jpg
http://www.buran.ru/images/jpg/posle06.jpg
http://www.buran.ru/images/jpg/posle07.jpg
http://www.buran.ru/images/jpg/posle08.jpg
http://www.buran.ru/images/jpg/posle09.jpg
http://www.buran.ru/images/jpg/posle10.jpg
http://www.buran.ru/images/jpg/posle11.jpg
http://www.buran.ru/images/jpg/posle12.jpg
http://www.buran.ru/images/jpg/posle13.jpg
http://www.buran.ru/images/jpg/posle14.jpg
http://www.buran.ru/images/jpg/posle15.jpg

While most of them are pretty ordinary - some damage occurs on any
flight, pay special attention to image 15. That's a breach of teh
wing structure, caused by poor joints between the Carbon-Carbon
Leading Edge and the Ceramic Tiles that cover most of the wing skin.
The Russians were fairly coy about the internal damage, but from the
scarring and marks left by hte exiting material, it wasn't trivial.
At best, you're talking about rebuilding/replacing the wing. At
worst, it goes to Monino and you fly the #2 flight article. Thay're
lucky that it occurred out toward the wingtip. If it had been where
the chine & the wing come together, where the shock impingement from
the bow shock occurs, (And where Columbia's damage occurred), it would
have been much, much worse.

Interesting.


STS ~100 manned flights, two total losses, 14 deaths.

A hair over a 98% success rate, a bit better than Soyuz (Which also
had 2 fatal flights, with 100% crew loss on each, (But smaller crews),
and several launch aborts. And a number of nasty landing incidents.

Really? I cannot easily find a total for the number of Soyuz missions
but
feel sure it must be way over the 100-odd of the STS. Do you have better
figures?

Currently, the number is 90 Soyuz flights, and 112 Shuttle flights.
http://space.kursknet.ru/cosmos/english/main.sht hads been keeping a
running total, valid through late May, 2004. (no flights since then)

And to me the survivable aborts are an indication of the robustness of
the
1960s design. The people on Challenger would have loved a surviveable
abort
system. The people on Columbia would have loved merely to have suffered
a
nasty landing incident.

They're not really relevant - every vehicle, from a Skateboard to a
Shuttle, has failure modes which are not survivable. If the aborts
had taken place at a slightly different time, or the reentry and
landing incidents, like the time a Soyuz Service Module didn't detach
after retrofire, causing the Soyusz to reenter not heatshield first,
but Aluminum hatch cover first (The SM burned away, allowing the
spacecraft to reorient itself before the crew was lost), and the
guidance problems that have caused some reentries to occur hundreds
of miles off from their targets could very easily have been much worse.

Aviation, and especially Spaceflight, is all about tradeoffs. What
sorts of system could have been aboard Challenger that would have
extended the survival envelope significantly, and wouldn't have been a
hazard during most of the flight?

Simple. A parachute for each crew member and a bail out pole, as they fitted
post-Challenger, might have at least given them a sporting chance.

And which wouldnt' require some
compromise of the stucture? What system could possible have turned
Columbia's loss to a nasty landing incident? I don't see any systems
that would allow a successful bailout at Mach 25/200,000'. (You
could, I suppose, postulate something like MOOSE, but that's only
useful before the retro burn occurs)


(I never mentioned Soyuz btw!)

Whenever the "Two Accidents, 100% crew loss" line comes up, a
comparison with Soyuz reliability is not far behind. There's no
reasonable comparison to anything else, after all. Buran made 1
limited flight, got broken, although the full extent still isn't
known, during that flight, and sat in the assemble building until the
building collapsed on it.

There's no objective indication that the expendable Soyuz capsule is
any safer than the STS.

Er.. how about the fact that the STS is currently grounded for safety
improvements after the last fatal crash? Leaving Soyuz as the world's
only
manned orbital vehicle, other than the Chinese and maybe Bert Rutan!

That's not objective, it's subjective.
Because the Russians, (and for that matter, us) are willing to accept
the risks that flying Soyuz right now represent. That doesn't make it
risk-free. Anytime you fly anything, whether it's a kite or a 747
with 500 people aboard, or a spacecraft, you run the risk of a fatal
crash. If you fly something enough, it becomes pretty much certain
that you'll crash it. To a large extent, it's a question of whether
the risk is perceived to be sufficiently minimized. Here in the U.S.,
we see that there are steps that can be taken to reduce the risk of
Shuttle flights, and we'er willing to take the time to implement
them. I don't think there's a lot that you can do to make a Soyuz
less risky. (Which does not make it risk free).

Granted.

As for Burt Rutan, please don't make the mistake that SpaceShipOne is
the harbinger of entry into orbit. It's not. The design is very
heavily optimized for a single, very limited goal - getting an X-prize
equivalent mass to 100 km altitude. The peak Mach Numbers for SS1 are
down around Mach 2, the materials are all conventional, and the
"shuttlecock" re-entry profile isn't going to hack Mach 25. Don't get
me wrong, it's an excellent achievment, but useful Space Travel it
isn't.

I still think it is a very good step in the right direction. Waiting with
bated breath...


I'd say the Russians realised they had no need of a shuttle and quit
while
they were ahead.

More like they couldn't afford it. Both Buran and Energia (The
booster)

Well sure. It is true that their country did collapse during the
devlopment
of the Buran and Energia projects, leading to their cancellation. My
point
was that this wasn't because they were inferior kit, quite the contrary.

But there also isn't enough sample size to claim with any validity
that it was superior, either.

No. I still think though that is was a shame it wasn't persevered with.

John