Space Science in Spacelab

by Jeanette Cain

Earth's gravity force cannot be changed on the ground, but space allows scientists to carry out experiments with gravity. Gravity keeps humans bound to the Earth, but gravity may also refer to the mixture of two fluids. Bodies in orbit cannot escape Earth's gravity, but when an astronaut drops any object in the orbiter, it will float. If you were parachuting, you would recognize this as a free fall effect. A spacecraft in orbit will be in a free fall toward the Earth, but it will never make its destination. This is weightlessness, or microgravity. Weightlessness provides scientists the opportunity to explore gravity's effects on the biological and physical systems.

In 1973, the United States launched its first space lab, Skylab, into orbit (in 1971, Russia's Salyut 1 was launched as the first space station). Skylab carried out experiments on human behavior to study the effects of long time periods on the human body when in space. They also learned much about solar flares. Solar flares originate on the Sun when energy and matter explode. The solar flares affect the areas around the Earth, and when strong enough, will disrupt satellite communications and cause power outages.

The Spacelab space station was designed by the European Space Agency. It was calculated to fit within the space shuttle's payload bay. Spacelab had two pressurized laboratories to experiment with projects that needed to be subjected to the outside space. Spacelab was launched in 1983, but was retired on its last mission in 1997.

The shuttle orbiter served as sleeping quarters for the astronauts, which allowed them to work in Spacelab by floating through the access tunnel. The racks were specially prepared areas for carrying out the experiments: investigating crystal growth and cell development observations. The racks would be constructed for the particular type of experiment to be observed and researched. Spacelab carried a Biorack holding samples of microorganisms and cells in an incubator. Experiments studied the affect of microgravity on cell behavior and development. the Anthrorack was designed to study the affects of microgravity on the human body.

Microgravity experiments were varied. The study of heart and lung behavior during long space stays, plus the digestion process was carried out by Russia's scientists. Mir grew wheat seeds to discover the affects microgravity would have on their growth. Experiments for discovering efficient methods of making computer semiconductors was through crystal growth observation. Spacelab carried out 2 microgravity missions. The experiments had been created by scientists around the world, but the crew on the shuttle performed them. Theses included microgravity on bacteria, the human nervous system, lentil seedlings and shrimp egg development.

A visiting NASA astronaut, Shannon Lucid, performed experiments on egg development in Mir's incubator in 1996. The results were compared with the same egg development phases on Earth. The eggs had more abnormalities than those on Earth, but it was considered to be a radiation effect rather than weightlessness.

Sources:

1. Couper, Heather and Nigel Henbest. Space Encyclopedia DK Publishing, Inc.: NY 1999

2. Editors. Secrets of the Universe. International Master Publishing: US. 1999