RESEARCH MISSIONS

The Space Shuttle is used to support scientific research in such diverse fields as astronomy, physiology, and materials processing. It has delivered into orbit a variety of scientific satellites and observatories. The Shuttle has also been used to carry Spacelab and to repair or recover scientific satellites. For some fields, such as biological and biomedical research, the Shuttle is an asset; for others, automated spacecraft are more appropriate and economical.

The Shuttle was first used to retrieve, repair, and release a satellite in 1984, when astronauts repaired the Solar Maximum Mission satellite in the payload bay of Challenger.

THE SPACE SHUTTLE TODAY

The Shuttle has been the principal U.S. launch vehicle and the only U.S. craft for human spaceflight during the 1980s and 1990s. Although it has not flown as frequently and economically as hoped, it has provided access to space for a variety of missions.

In 1994 and 1995, NASA and the Russian Space Agency began a series of joint missions involving the Space Shuttle and the Mir space station. Both nations expect such international ventures to be economically beneficial.

SPACELAB: A SHUTTLE LABORATORY

Built by the European Space Agency, Spacelab is a modular scientific laboratory carried in the Space Shuttle. Scientists from about a dozen nations use it to conduct research in space.

Spacelab consists of an enclosed pressurized module, where scientists work, and smaller unpressurized pallets. The pallets carry telescopes and other instruments that require direct exposure to space or do not require a human operator.

The module-pallet configuration and experiments can be changed to meet the scientific objectives of each flight. Spacelab missions may be dedicated to a particular discipline--such as life sciences, materials science, astronomy, or Earth observations--or they may be multi-disciplinary.