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[[NASA Logo]] National Aeronautics and Space Administration

Space Shuttle Orbiter

Space Shuttle Orbiter

A number of cloud-types form the backdrop for this scene of the Earth-orbiting Space Shuttle, captured by a 70mm camera aboard a free-flying satellite (SPAS) during STS-7, in June of 1983.

The space shuttle stays in orbit because of (1) the speed it has been given during launch, and (2) the Earth's gravity. There are no engines running during this phase of a shuttle flight.

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. The shuttle circles the Earth traveling at a speed of about 17,500 mi/hr (about 5mi/sec!). At that speed, it takes about 90 minutes to go around the Earth once. It circles the Earth, following the same path in space, while the Earth rotates beneath it.

In the nose of the orbiter is the two-level "crew cabin", a pressurized area where the astronauts live and work during the shuttle missions.

The part of the shuttle that is where the passenger section of an airplane would be is called the payload bay. It is 60 feet long and about 15 feet across, and is used for carrying satellites and scientific experiments into space or back to Earth. The payload bay is not pressurized, and while the shuttle is in orbit, it is open to space.

The payload bay doors play an important role in the shuttle mission. When these doors are open, the heat that the shuttle's electronics generate can be radiated into space. This is the primary

[[Image of Rocket Parts]]
Overhead Window
Crew Cabin
Payload Bay Doors
OMS Engines
[[/Image of Rocket Parts]]

means of cooling the shuttle. Because of this, the payload bay doors must be opened within the first couple of hours of the flight, or the shuttle has to return to Earth.

The OMS engines, at the rear of the shuttle, are used to change the shuttle's orbit and to leave orbit to return to Earth. These engines can only be used in space; they can't be used after the shuttle re-enters Earth's atmosphere.