[another_someone]

ammmm.... i dont think that the astronaut cant travel in space if he got stuck there.
          and supposingly he managed to move towards earth so his spacesuite will definanety burned. you know that if only a tiny pebble will srtike his spacesuite so it will pass through it. so imagine how will his suite can tolerate this much temp. due to friction force of earth's atmosphere if an big meteorite got evaporated.


(hey if something is wrong so tell me i'm new here from india)  []

Hello Duke, from India, and welcome.

An astronaut that is close to the Earth will fall to Earth like anything else.  The reason why most astronauts do not fall to Earth is because they are in fact in orbit around the Earth (i.e. they are spinning around the Earth fast enough so as to compensate for the gravitational pull of the Earth), but if they stopped orbiting, they would just fall down.

Yes, a tiny pebble can go through his space suit - but it all depends upon the speed of the pebble.  The problem is that in space, because there is almost a total vacuum, things can travel very, very fast, and so can be very dangerous, even if they are small.

You are right that the space suit will not tolerate much temperature, or at least, it will not tolerate the thousands of degrees of temperature that most space vehicles re-entering the Earth's atmosphere will be subjected to.  So if the astronaut is to survive re-entry, we have to find a means to prevent him coming in so fast as to create such high temperatures, because it he is subjected to those temperatures, he will fry up very quickly.

The point is that is a total vacuum, the only way to slow things down (or speed things up) is by use of rockets; but space is not a total vacuum (actually, nowhere exists a total vacuum - many places in the universe are very close to a total vacuum, but it is physically impossible for anywhere to be an absolute vacuum).  So the question was whether a very, very, large parachute could not still be deployed in space in order to make use of the very, very, low density of matter that does exist there, in order to slow the falling astronaut down sufficiently so that he does not enter the atmosphere very fast, and so he will no burn up as he enters the atmosphere.

[turnipsock]

Didn't somebody jump out a balloon from a great hight, a long time ago, and didn't have any problems?

http://hypertextbook.com/facts/2004/JerardKneifatiHayek.shtml

[Bored chemist]

Yes, and it was mentioned in the 8th post in this thread 30/11/07.

[lyner]

I think we discussed something like this before.
There are two lots of energy to get rid of for an astronaut in orbit. He (or she) will have KE, due to the orbital speed and PE, due to height above the surface. Both the KE and PE,  per kg are  about 3e7J at 300km altitude.
Getting rid of the initial KE is more of a problem, I think, than dealing with extra KE transferred from the PE, which builds up only gradually.
To dissipate the energy safely, without excessive heat generation, it is necessary to do it over a long time.I am surprised that 'they' don't seem to consider a very long glide for re-entry (lone astronaut or shuttle)- taking many orbits, possibly. If there is enough atmosphere to produce drag / friction / heat, then there should be enough to produce lift. This could keep the craft / person to an altitude at which there is a much lower power dissipation, compared with the Shuttle, which plunges in - brute force and ignorance - and gets white hot.
I seem to remember objections on the grounds of the problems involved with supersonic flight control but this would seem to be a 'detail' to me. You would need variable geometry and computer control but it sounds preferable to the roasting tiles method which is even more brown trouser stuff.
I guess the lone astronaut bit is a no no, although the original re-entry vehicles weren't much bigger than the astronaut, so you could regard them as just a big space suit(?).

P.S. The balloonist had no initial KE to get rid of.

[Paul]

why do we have to orbit...?  cant we just get high enough above to just hang loose in space....then enter very slowly in a straight line?  erm....no i guess earth would just zoom off and away right?! :-P  haha