i have a question about the space shuttle?

Question

i watched it land the other day, and it was loud, i didnt know that it was running when it came back into the atmosphere. I thought it glided back to land because it cant fly on its own? And if it does glide, what if its going to fast/slow on approach?

Answer 1

The shuttle glides in during the last phase of landing, i.e. there is no propulsion method used.

The shuttle is loud on landing due to the noise of the air at the high speeds the shuttle lands at. Also, once on the ground, the parachute is deployed to slow the shuttle, adding additional noise.

Shuttle landing is very tricky. The pilot must maintain the proper glide slope to control speed and altitude. If he is too high, then the speed at landing will be too high and he could overrun the runway. If he is too low, then the shuttle could stall (wings loose lift) and he could crash, or land short of the runway.

"When the approach and landing phase begins, the Orbiter is at 10,000 ft (3048 m) altitude, 7.5 miles (12.1 km) to the runway. The pilots apply aerodynamic braking to help slow down the vehicle. The Orbiter's speed is reduced from 424 mph (682 km/h) to approximately 215 mph (346 km/h), (compared to 160 mph for a jet airliner), at touch-down."

From Wikipedia, the free, online encyclopedia at:
http://en.wikipedia.org/wiki/Space_Shuttle

If you would like to try to land the shuttle yourself, there is a simulation you can try at:
http://imedia.ksc.nasa.gov/shuttleland/index.html

Hope this helps!
[from a retired NASA engineer]

Answer 2

Well, there are two reasons for it to be loud, depending on which phase of the landing you witnessed.
The shuttle is coming down from space at 25 times the speed of sound. Until it slows to less than Mach 1, it will have a sonic boom. That is loud, but very sudden if you are exposed to it, it feel just like someone slamming the door of a house so strongly the whole building shakes.
Then, once below Mach one, the shuttle will still make aerodynamic noises, the same kind of howling noise you hear from a windmill, riding a bicycle fast enough, or even fanning air in your ear by waving your hand close to it. It does glide without engine, the only noise you hear is wind related.

The shuttle approach is monitored closely, both by on board computer and by equipment on ground. The shuttle will thus try to keep some excess speed, so it will not approach too slow. This means it is usually fast, on the other hand. To bleed excess speed, the shuttle banks and rolls gently (it actually does that while going atmospheric entry as well, at hypersonic velocity), and can open its split rudder to act as an air brake. If it lands a little "hot", there is no worry as the runway is plenty long, that it has good brakes and a drag chute.

Answer 3

The shuttle is only gliding when it returns to earth. Some systems like the APU (aux power unit) are running. The APU is needed to have hydralic power which lets the pilots steer the shuttle.

As far as too fast/slow. They (the controllers and the pilots) have to get it right, or else.... it wouldn't be a good day for them.

Answer 4

The shuttle is actually breaking the sound breaker with sonic booms right before it lands. It is only a glider with some manuver type jets and flaps. If it doesn't land at the right speed and over shoots the landing strip, you're dead.