Going to the moon...again?

Sylvia Else wrote in message ...
Charles Buckley wrote:
Well, only indirectly. The point was for the USAF to be able to
launch and land within one orbit.

I think it's this single orbit thing that the doco must have been
referring to. They said the USAF required the shuttle to have a long
descent path. This struck me as odd at the time, because it was far from
clear why the military would care about it.

As I understand it, this requirement gave the shuttle a long hot period,
which in turn impacted on the design for the insulation, etc etc.

Ye Gods! You mean a 20 year program was stuffed from the beginning,
because of that? They never even used that ability.

sigh

Ye gods indeed. But guess what? That's not even the
worst thing wrong with the Shuttle design / design
process. It's a godawful mess from wall to wall,
just about.

Greg D. Moore (Strider) wrote:

"Sylvia Else" wrote in message
...

Ye Gods! You mean a 20 year program was stuffed from the beginning,
because of that? They never even used that ability.


Actually apparently NASA does make use of the cross-range capability to
increase landing opportunities.





Abort opportunities. Not landing. None of the three landing
sites it has used has actually required much in terms of
cross-range.

"Ool" wrote in message
...

Until rocket planes, space elevators, or mass driver cannons become a
reality it'll always be disposable rockets for the stretch between sur-
face and LEO. Which isn't so bad--we drink soda from throw-away cans,
after all.

Recyclable cans.

"Chosp" wrote in message news:xqsXb.68545$F15.39135@fed1read06...
"Ool" wrote in message
...

Until rocket planes, space elevators, or mass driver cannons become a
reality it'll always be disposable rockets for the stretch between sur-
face and LEO. Which isn't so bad--we drink soda from throw-away cans,
after all.

Recyclable cans.

So are rockets, if you fish them out of the ocean and melt them. But
that's a silly argument unless you have environmental concerns. Cer-
tainly it's not the raw material that is scarce but the manufacturing
them that makes them expensive. And if reusing rockets causes more
work and expenses than molding all new ones then let's mass-produce
all new ones. If not, let's reuse old ones.

So far the "reusability" was supposed to make things cheaper but did
exactly the opposite. If you can find a way of making them economical
then, by all means, let's go ahead with the RLV. Otherwise, let's
make them E! And this time let's scrap'em *after* we've used them,
not before, as in the case of the last Saturn Vs or Energiya!



--
__ “A good leader knows when it’s best to ignore the __
('__` screams for help and focus on the bigger picture.� '__`)
//6(6; ©OOL mmiv :^)^\\
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In article ,
Sylvia Else wrote:

Joe Strout wrote:
You want cheaper and safer ways of doing it? Here's how you get that:
by doing it. A lot. Involving a lot of different companies. High
flight rate and competition will drive the costs down. Money spent on
research almost certainly will not.

The problem from my perspective is that a way of getting to the moon
will be developed (again!), and then over a period of time, money will
be spent on refining it. We end up with the best horse and cart that
money can buy, but what we wanted was a supersonic airliner.

It's fine to want things, but the reality is, we're at the
horse-and-cart level of interplanetary (including translunar) flight.

Suppose this were the 1800s, and you and I both wanted to go out West
from the new American states on the East. I say, I'm going to get
myself some horses (or oxen) and wagons and go for it. You say, you're
going to do research into supersonic airliners, which obviously would
get you there much faster and in greater comfort and safety.

Who do you think is going to get the gold?

It's only be spending money on research that people get the chance to
start again with a blank sheet of paper.

Nonsense. A blank sheet of paper is where the *engineering* starts, and
there *will* be blank-paper engineering for the CEV and associated
support craft. The fact that they may come out looking superficially
similar to things that worked well in the 1960s should not be a shock.
Modern cars have four wheels, just like the very first cars; we don't
need jetpacks and hovercars to get from here to there.

We have all the research we need. What we need now is development, and
in particular, commercial development.

,------------------------------------------------------------------.
| Joseph J. Strout Check out the Mac Web Directory: |
| http://www.macwebdir.com |
`------------------------------------------------------------------'

Charles Buckley wrote:
Abort opportunities. Not landing. None of the three landing
sites it has used has actually required much in terms of
cross-range.


In any case, it would probably have been cheaper to build landing sites
than have the cross range ability and all its downstream effects. Mind
you, whether that was feasible given geographical and political
constraints I can't say.

Sylvia.

Charles Buckley wrote in
:

Greg D. Moore (Strider) wrote:

"Sylvia Else" wrote in message
...

Ye Gods! You mean a 20 year program was stuffed from the beginning,
because of that? They never even used that ability.

Actually apparently NASA does make use of the cross-range capability to
increase landing opportunities.

Abort opportunities. Not landing. None of the three landing
sites it has used has actually required much in terms of
cross-range.

Nope, they've used it to increase nominal landing opportunities as well.
See http://spaceflight.nasa.gov/shuttle/reference/green/entare.pdf for
entry crossrange data for past missions. The data appear to be fairly
uniformly distributed right up to the flight rule limit of 800 n.mi.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

Charles Buckley wrote:

NASA has a good rundown of the whole decision process at:

http://history.nasa.gov/SP-4221/sp4221.htm


Thanks for the link, Charles.

I've taken a look at that.

There are dangers in comparing the real shuttle hardware that's in place
with hypothetical other approaches. Still, I found the idea of a
titanium stubby winged orbiter quite compelling.

The objections to this seem to have been:

a) Not so much knowledge in the industry of titanium manufacture. Well,
how many of these things did they intend to build anyway?

b) Cross range limits. Could have been lived with.

c) Transition from deep stall descent into normal flight. Aviation has
rightly been concerned with deep stalls, and it has caused a few
crashes, but these were aircraft that were never intended to operate in
that region. There was also concern that you have a craft that is
presumably travelling in a fairly steep path at the point where it has
to start flying, so it will accelerate, downward, quite quickly. But
this is just physics, and should be manageable.

On the plus side, you have a much smaller area to protect from heating.
More energy is dumped into the shock wave, and less has to be lost from
heating. Lower structural weight. And the aerodynamics are of a craft
operating in the subsonic region - not even transsonic. You don't have
to build a hypersonic glider with acceptable subsonic characteristics.

Will this be revisited now? Or will the next shuttle also be a delta wing?

Sylvia.

Charles Buckley wrote:

There would, however, have had some real interesting choices on
polar orbits. One entire hemisphere offers very little by way of
landing zones for a vehicle with a 200 mile crossrange.

Looks pretty baren out there even with 1000mile crossrange, particularly
when you look at the politics of the region.

Does anyone really believe in suborbital aborts anyway? If things have
gone so badly wrong that abort to orbit isn't an option, it must all be
guesswork, assuming you even have an intact orbiter.

Sylvia.

On Mon, 16 Feb 2004 08:37:47 +1100, in a place far, far away, Sylvia
Else made the phosphor on my monitor
glow in such a way as to indicate that:

..will the next shuttle also be a delta wing?

Let us fervently hope that there is no "next shuttle."