P17tools3

Space shuttles have over 600,000 parts, which makes them the most

complicated man made machines. Since space vehicles are very

expensive, the government started making the space shuttles, and
reusing them. The crawler brings the space shuttle to the launching
pad. The crawler has a top speed of 2 miles per hour, and goes 1 mile
per hour with the shuttle on it. There are 5 rockets to bring a space
shuttle into orbit. Some rockets can go 25 times the speed of sound.
In two minutes the space ship is 25 miles up above the earth. During
its launch, the main rocket boosters are jettisoned and fall back to
earth for reuse.

Once in space, the astronauts sleep upside down in sleeping bags. Zero

gravity causes loss of muscle mass since you don't need to use them in

space. To help stop this, astronauts exercise on a stationary bike 2

hours per day. When they go outside into space, they wear a special
suit. It is made for temperatures of -264 degrees Fahrenheit to 290
degrees Fahrenheit. The astronauts use jetpacks to assist in
movement when they fix satellites or other objects in space. The
space shuttle lands like a plane on earth, and uses a parachute to help
it slow down.