They are going through the same atmosphere on the way up as the way down, so why don't they get really hot on the way up as they get when they come down?
2006-11-08 09:31:52 · 15 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
Every single answer that says friction is the cause is wrong. The high temperatures experianced in reentry is due to the compressive shockwave created by hitting the atmosphere at ultra high velocity. It's like when you press a bike tire pump, the air gets hotter. If the reentry heat were only due to friction, the shuttle and reentry probes would be shaped more like the SR-71 or another aircraft to slice through the air with less resistance, rather than the blunt shapes they actually have..
As a craft goes up the air is getting thinner as the craft accelerates, so the shockwave heating is quickly offset and disapated. As it re enters, the atmosphere is getting thicker and the compression is greater and greater until the craft can slow.
2006-11-08 12:01:09 · answer #1 · answered by Chance20_m 5 · 4⤊ 1⤋
As the rocket and or shuttle goes into outer space, the density of air is decreasing. The lower density of the upper atmosphere exhibits less friction on the shuttle craft. Friction creates heat. The shuttle is also not exiting the atmosphere as fast as it enters the atmosphere on re-entry.
As the shuttle re-enters the atmosphere, it has gravity pulling on it as well as the rocket engines propelling it. These two combined give a greater speed upon re-entry than when lifting off. As the shuttle enters gets closer to earth, the density of the atmosphere increases causing more friction. The friction is what causes the shuttle to potentially explode. If the shuttles or pods did not have a layer of ceramic on the bottom, they would break apart. The ceramic layer has lots of little holes in them that trap air. Air does not transfer heat very well, and so, the heat from the friction does not get to the shuttle or pod to break it up.
In the case of Columbia, a small part of the ceramic layer was broken off in take off and it created a hole that the heat could travel through.
2006-11-08 09:40:50 · answer #2 · answered by chemical_kenny 2 · 1⤊ 2⤋
When going up the craft is launched with a tilt in in lauch angle - Also since it has to overcome earths gravity it goes up slow when compared with re-entry. When re-entry the earth's gravity is pulling it down with immense force that increses the speed of the craft by many times over giving rise to friction with the atmosphere
2006-11-08 16:39:21 · answer #3 · answered by Siva 2 · 1⤊ 1⤋
The space craft is accelerating from zero and encoutering an atmosphere of ever decreasing density. On reentry, the spacecraft is already travelling at slightly slower than escape velocity. As it enters the atmosphere, it is encountering an atmosphere with increasing density. Hence the friction of reentry is greater spead out over a quicker period of time that it is on launch.
2006-11-08 09:43:54 · answer #4 · answered by Scarp 3 · 1⤊ 1⤋
Greetings!
On a launch the craft is going up at a slight angle and at a slower speed. On re-entry the craft catapults after orbit and enters at a much higher rate of speed and when hitting atmosphere is experiencing the increased friction.
Good Luck
2006-11-08 09:34:31 · answer #5 · answered by Anonymous · 2⤊ 2⤋
Orbiting spacecraft travel at immense speed to maintain their orbit. They simply cannot slow down fast enough without killing the crew and possibly destroying the craft itself. For re-entry, the craft does fire rockets to slow itself down, but its speed is still considerable. There's also a matter of the earth's gravity, which makes the craft fall down as soon as it loses its orbital speed. As another person here said, it's indeed better to let the atmosphere do the job of slowing down.
2016-05-21 22:45:41 · answer #6 · answered by Anonymous · 0⤊ 0⤋
All of the previous answers are laughably inaccurate or incomplete. I am not smart enough to answer it but I am smart enough to mock the terrible answers you have received. BTW it does get really hot on the way up. If you can combine 3-4 of the most intelligent of these awful answers you may come close to the correct answer.
2006-11-10 15:02:25 · answer #7 · answered by Anonymous · 0⤊ 1⤋
its not going so fast onlaunch so it does not create as much friction but when it returns to the earth's atmosthere its is going several thousands of mph. creatinga lot more friction
2006-11-08 09:43:11 · answer #8 · answered by roy40372 6 · 1⤊ 1⤋
it is harder to come back into our atmosphere, so, just like meteors, they get hot and if the shuttle isnt strong enough, it will burn up
2006-11-08 09:35:18 · answer #9 · answered by mnayr22 2 · 1⤊ 2⤋
The above answer is correct, for the most part. They aren't ascending NEARLY as quickly going up. Also, it has to do with ionization.
2006-11-08 09:39:48 · answer #10 · answered by cyanne2ak 7 · 0⤊ 3⤋