Why didn't the hole in columbia shuttle wing, allowed hot gases to enter, when it left the earth atmosphere

Question

The reason for Columbia shuttle, disaster is now well known. a piece of foam detached (during launch) and strike the wing , which made a 25cm deep hole...and this hole allowed hot gases to penetrate, when columbia reentered the earth atmosphere.

but it crossed this same atmosphere , while going up...during launch, than why didn't the gases penetrated when it moved out of earth's atmosphere. as the speed both the times were approximately same.

this heating up, should also must occur, while going up..but, there was no such heating and it safely reached the space.

Why this hole only affected during re enty?

Moreover the heat sensors while launch did not showed any raised temperature

Answer 1

The hole was in the heat shield and had no effect until the shuttle entered the atmosphere at 14,000 miles per hour.

Answer 2

The shuttle has ascended out of most of the atmosphere before it's speed is very high. So you are incorrect. The air is not that hot during ascent becaue it doesn't move that fast at that altitude.

Answer 3

It was going up at a much slower rate than during descent.  From launch, the shuttle must accelerate to about 7900 meters per second in order to maintain orbit.  By the time it gets to that speed, it is essentially out of the atmosphere.  But upon reentry, that speed, plus even a little more, is attained when the shuttle begins to plow into the upper atmosphere.  The only way that speed is lost is by drag, which in turn generates heat. A very heavy shuttle moving at about 8000 meters per second has lot of kinetic energy which must be converted into heat.  Thus much more heat is generated upon reentry.  The effect is also magnified by the fact that the pilot banks the shuttle very steeply from side to side during reentry to drain off the speed even quicker, which of course generates even more heat.