Chuck Yeager described " Augering In " , which is a severe deceleration into terrain at an angle close to perpendicular ; (my words). Don't try this at home.
Chuck Yeager described " Augering In " , which is a severe deceleration into terrain at an angle close to perpendicular ; (my words). Don't try this at home.
Infraction of the air/ground interface. - From the movie Fearless, I believe.
Solfe
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'That was tops! Who's not good at math? I was all, "Four!"' - Finn, Adventure Time.
Always an interesting read.
Dan
Modifying the SSME for an in-orbit restart would be the comparatively easy thing here.
The advantage of the shuttle is that it could be compartmented, holding a lot of air, water etc etc, and a portion of it could hold a lander? Maybe....but you are still better off building a separate,dedicated interplanetary vehicle in orbit and using the shuttle to get to and from orbit.
Dan
You mean what would be the next task for making the shuttle lunar-capable?
Uh.... figure out how to get all that hydrogen and oxygen up into orbit with the orbiter, either with... I don't know? A massive ET with extra boosters to lift the hulking thing? or maybe the Shuttle-C fuel transfer thing? Or... I don't know....
Then upgrade the TPS of the shuttle...
The problems you'd have to solve to send that big hulking thing into lunar orbit are daunting.
Agreed...
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How wbout we extend the atmosphere for additional aerobraking? On the count of three, everybody in the western hemisphere look straight at the shuttle and blow!
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
If you reenter at the correct angle, using a lifting reentry profile (which is what the shuttle uses anyways), you can keep the G-force down to no higher than it already experiences reentering from orbit. The duration would be longer, but the acceleration would be the same. Of course, the heat load would be immensely higher, but there really shouldn't be a structural concern.
Regarding lifting entries, are you familiar with the Apollo skipping-out-of-the-atmosphere problem if you enter on the shallow end of a couple of degrees wide reentry corridor?
There's something I never had a clear answer on.
As a youngster growing up with Apollo, I always heard about skipping off the atmosphere and "being lost in space".
But; as I learned more, I realized that the re-entry speed is just below escape velocity, because they only needed to be "captured" by the other body's gravity.
So; wouldn't any "skip" keep you in a highly eccentric Earth orbit?
It might take a long time (days between skips), but each skip could slow you down to LEO speeds before re-entry.
True. I was actually thinking about whether it could slow down fast enough to stay in the atmosphere without excessive stress (being intended to take rather lower accelerations than the Apollo command modules), but even if it can't...you're taking a shuttle to the moon, you can work out some way to give it enough endurance to have separate aerobraking and reentry phases. Still might be more mass efficient to carry a capsule along to drop the astronauts off on the first pass and modify the Shuttle to land unmanned, bleeding its orbital velocity down over a long period of time with multiple light aerobraking passes, than to equip the entire Shuttle to take the reentry in one go...
I did some rough estimates for modifying the OMS pods to use propellant tanks added in orbit, which seemed somewhat more feasible than shipping up LOX/LH2 propellant and refilling the ET. The required propellant mass looks like it'd be around 16 times the payload capacity of the Orbiter...about 4 times the mass of a fully-loaded Orbiter.
Stressing the word "highly".
The way I understand it, for such an eccentric orbit, It would be a lot longer than "days" between skips.*It might take a long time (days between skips), but each skip could slow you down to LEO speeds before re-entry.
Meaning that by the time they slowed down "enough", consumables would be long gone.
*If anyone can show differently, I welcome the correction.
Last edited by R.A.F.; 2012-Aug-01 at 03:56 PM. Reason: added "the way I understand it"
I'm not an authority either, but my basis is the Apollo flights and how long it took to get there and back.
Apollo 13 was 7 days. Subtract the extra orbit around the moon, and subtract some of the orbital velocity from the first skip, and you are definitely in the "days" range.
Yes; this thought is independent of the problems of consumables and such because we could have had Noclevernames' hibernating bears.
Hibernating bears would be useless too, at least in the Apollo case. Once the service module was jettisoned, the command module was running on reentry batteries which could only last a few hours.
We could send some electric eels up with them. 500 Watts per eel, so how many would we need to charge up those batteries?
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary