Posted on 07/12/2004 7:40:58 AM PDT by PeteePie
I didn't see anything on the "Spaceship" that looked like a heat - shield, and am a little curious as to why even early suborbital capsules had to contend with the scorching heat of "Re-Entry", while it does not appear to be a big deal with this rig.
What keeps this craft from burning up on re-entry like the last Space Shuttle did?
As you can probably tell, I have lots more curiosity than clue here...
I agree in principle. It's not NASA per se, but someone or someones, probably several interest groups, are resisting space development. Somebody will get to a Senator and the Senator will get to a bureaucrat and the bureaucrat will dig through the statutes and some regulation will be found. They may be letting this one fly for two reasons: first, it isn't really going anywhere, and second, it might end in disaster and they wouldhn't have to worry about space development again for several years.
I wish I knew. That orange stuff on the underside of the nose and leading edges was supposed to be special paint which changes color in response to heat so they could see how hot it actually got.
"What keeps this craft from burning up on re-entry like the last Space Shuttle did?"
The Mercury capsules had a high weight/drag ratio, and thus dropped from sub-orbit like a bullet. SS1 has a low weight/drag ratio, so it floats down like a feather (more or less).
There is a heat shield on SpaceShipOne. It is more of a thick paint on the nose and the leading edges of the wings and must be repainted for each flight. The structure is plastic with carbon fiber reinforcement and can't take much heat at all. At 2000 to 3000 there is some heat from friction with the air.
Since SS-1 is very light, that helps.
OTOH, the resins used to build fiberglass airplanes start to weaken at about 200° F.
An aircraft parked on the ramp at PHX gets hotter than that.
I really don't know how they do it (the secret of which may be the big story here.)
Here at the house, I have Burt Rutan's set of three video tapes on basic composite construction. I think they are circa 1980 or so, so they may be collectors items now.
21 - "What keeps this craft from burning up on re-entry like the last Space Shuttle did? "
sub-orbital flights really don't go that fast for super-heating. Sort of like rubbing your hands together, they get hot, but you can't make a fire.
IIRC, the original sub-orbital Redstone flights of Alan Sheppard, et al, had heat shields mostly to test heat shields for orbital flights of the Gemini.
Rutan's bird flys much slower, only 2-3,000 mph. The shuttle broke apart at 12,000 mph after major decelleration from about 18,000 mph.
There have been some NASA tests for ablative heat shields, which were turned down (too cheap) just make of bundles of wooden 2x4's.
28 - correction - "IIRC, the original sub-orbital Redstone flights of Alan Sheppard, et al, had heat shields mostly to test heat shields for orbital flights of the Gemini. "
should have been:
"IIRC, the original sub-orbital Redstone flights of Alan Sheppard, et al, had heat shields mostly to test heat shields for LATER orbital flights of MERCURY and THEN Gemini. "
28-"sub-orbital flights really don't go that fast for super-heating. Sort of like rubbing your hands together, they get hot, but you can't make a fire. "
CORRECTION:
"sub-orbital flights really don't go that fast OR LONG for super-heating. Sort of like rubbing your hands together, they get hot, but you can't make a fire. "
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