Is it possible to re-enter the earths atmosphere without heating up?

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sao123

Lifer
May 27, 2002
12,653
205
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somehow I think all of ye all are overthinking this...

when I went to NASA for a visit (fun trip) the VIP tour guide essentially declared the shuttle to be a "falling brick" during landing.
There is no reason we could not create an aerodynamic shape which would glide to its landing over the course of several orbits rather than fall from orbit in about 18 minutes.
 

Zeze

Lifer
Mar 4, 2011
11,395
1,189
126
Such thing only exists because they're free falling at high speeds, yes?

If we built a space elevator and we're just descending at a nominal speed, I don't see it magically getting heat up. Anyone care to chime in?
 

NetWareHead

THAT guy
Aug 10, 2002
5,847
154
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I think you could minimize the heat load.

The key is to shed your orbital velocity slowly. Usually during re-entry you shed your orbital velocity quickly and you see a lot of heating up. Even then the Apollo capsules came in much faster than the shuttle and experienced a lot more heating than the shuttle. If you could pricesly control and dip down into the upper atmosphere enough to sheed some velocity and the go back up again. Then dip back down and shed more velocity and then go backup again. Basically you flight plan shows a wave motion going up and down. You dip down shed velocity and then use your remaining velocity to stear yourself back up again and then keep repeating.

Yep...this is what Skip reentry is. http://en.wikipedia.org/wiki/Skip_reentry

Germany is World War 2 designed a bomber that worked on this skipping principle but in reverse. Utilizing skipping across the lower denser atmosphere as a way to stay aloft. http://en.wikipedia.org/wiki/Silbervogel
 

Jeff7

Lifer
Jan 4, 2001
41,596
20
81
It would make it harder to catch spam. I'll toss out the auto-archive idea again in the mod forums. I'm not sure what the software capabilities are in vB.
...
Set up a fund for the AT forums specifically for paying mercenaries to track down and eliminate any offending spammers.
I'm sure we would have no problem keeping money in that account.

One possible problem I can see: Mercenaries spamming us to offer their services. Olds would have to go after them himself, I guess.
 

mmntech

Lifer
Sep 20, 2007
17,501
12
0
Not sure on the physics but I suppose if you could slow a vehicle down enough it could re-enter the atmosphere without heating up to lethal levels.
 

kevinsbane

Senior member
Jun 16, 2010
694
0
71
Slowing it down... Just think about it this way... to get the Space Shuttle up to the velocity it's at (~6500m/s) requires a big fuel tank larger than it is, and two solid rocket boosters that is heavier that it is. To slow it down to something that can survive reentry without extreme heating, you would basically need the same thing.
 

Cheesemoo

Golden Member
Jun 22, 2001
1,653
20
81
Why is everyone concerned with Necro on this? Col. Kittinger's record may be broken today by Felix Baumgartner. = relevant.
 

JTsyo

Lifer
Nov 18, 2007
12,043
1,136
126
somehow I think all of ye all are overthinking this...

when I went to NASA for a visit (fun trip) the VIP tour guide essentially declared the shuttle to be a "falling brick" during landing.
There is no reason we could not create an aerodynamic shape which would glide to its landing over the course of several orbits rather than fall from orbit in about 18 minutes.

Isn't there a minimum angle for re-entry or you just bonce off the atmosphere?
 

NetWareHead

THAT guy
Aug 10, 2002
5,847
154
106
There is, I just don't know what it is.

Depends on your incoming speed and angle and what kind of g-forces the reentry vehicle can take. Choose the wrong angle and you either will bounce off the atmosphere and end up back in space or you may fall into the atmosphere at a faster speed, resulting in higher heating with destruction of the spacecraft possible. Human rated spacecraft generally reenter at lower speeds or at less steep angles than for instance an ICBM warhead.