The ozone layer.
3,000+ F
When the shuttle goes from the vacuum of space and enters the earths atmosphere, it heats up because of simple friction. The friction is from the shuttle going so fast and hitting the atmosphere. Same reason you sometimes see meteor showers.
Although it reaches incredible speeds, a Space Shuttle is not going fast when it enters the atmosphere. The gravitational pull of Earth, or just gravity, are pulling down on the space shuttle with immense force.
A meteorite.
The correct name for a shooting star is a Meteorite. Before a meteorite enters the Earths atmosphere it is called a Meteoroid.
+3,000 F.
First the Solid Rocket Boosters (SRB) parachute into the sea. Then the External Tank (ET) comes off and disintegrates in the atmosphere. The shuttle orbits the Earth. It may dock with a satellite then re-enters the earths atmosphere and lands. If all goes correctly.
A rock that enters Earth's atmosphere is called a meteoroid. As it travels through the atmosphere and heats up, it produces a bright streak of light known as a meteor or shooting star. If the rock survives its journey through the atmosphere and reaches the ground, it is then called a meteorite.
meteor
The streak of light across the sky caused when a space rock falls through the atmosphere and is heated to incandescence is a "meteor".
A sonic boom occurs when an object travels faster than the speed of sound. If the space shuttle enters Earth's atmosphere at a speed greater than the speed of sound, it will create a sonic boom. However, the shuttle typically slows down as it enters the atmosphere to avoid this effect.
When a space shuttle enters the Earth's atmosphere, it experiences extreme heat and friction due to the high speeds it is traveling at. This creates a plasma sheath around the shuttle which can interfere with communications. The shuttle also begins to slow down due to atmospheric drag.