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IN ORBIT!

The shuttle's orbit around the Earth: The space shuttle stays in orbit because of the speed it has been given during launch, and the Earth's gravity. There are no engines running while the shuttle is in orbit-they're not needed. The shuttle circles the Earth following the same path in space (like a groove in a record), while the Earth rotates beneath it.

The height of the shuttle's orbit depends on the purpose of the flight, but is always somewhere between 120 miles and 350 miles above the Earth. During STS-81, the shuttle will orbit about 250 miles above the Earth.

The shuttle orbits the Earth at a speed of about 17,500 mi/hr (about 5 mi/sec!); at that speed, it takes about 90 minutes to circle the Earth once. This means that the shuttle sees about 45 minutes of daylight and 45 minutes of darkness each time it goes around the Earth.

Side & Top Views of the Shuttle's Orbit 

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While in orbit, the space shuttle is a spacecraft, not an airplane. The shuttle doesn't need any engines to stay in orbit, and it doesn't matte which way it's facing; it can be traveling nose forward, tail forward, right-side up, or upside down. The KidSat cameran will point directly down at Earth when the shuttle is upside down; this shuttle orientation is called "ZLV", which means the minus z axis of the space shuttle (which goes through the top of the shuttle) is pointed in the "local vertical" (LV) direction. The KidSat camera will only be taking pictures of the Earth when the shuttle is in this orientation...upside down. 

07/10/96      Page 3.6