Friday, November 12, 1999
writer: Ann Ferrar Dusek
UPTON, NY - When the National Aeronautics & Space Administration (NASA) wants to test how cosmic rays affect astronauts and their spacecraft, they come to the U.S. Department of Energy's Brookhaven National Laboratory (BNL) on Long Island. The Laboratory uses its Alternating Gradient Synchotron, or AGS, to generate high-energy heavy ions, which simulate cosmic radiation in outer space. The AGS is the only machine in the United States that can simulate cosmic rays, and one of only four such machines in the world.
Beginning November 10th and continuing into next week, NASA-sponsored researchers from Brookhaven, Lawrence Berkeley National Lab, Johnson Space Center and other visiting institutions are conducting a series of radiobiology experiments. A primary goal is to understand the biological effects of cosmic radiation during future long-term deep space flights. The scientists are irradiating a variety of specimens, including fruit flies, worms, cultured cells from humans and mice, and DNA in solution, as well as industrial materials that may be used for space suits and for shielding the walls of the space shuttle and station.
Galactic cosmic rays heavy charged particles and energetic
protons that zip through space at high speeds pose a threat
to astronauts, who are also exposed to solar radiation composed
of various protons, heavy ions, and electrons. "At lower
orbits, the walls of the spacecraft block much of the harmful
radiation," says Marcelo Vazquez, senior liaison scientist
in the Brookhaven-NASA project, "but when astronauts are
high altitude, high inclination orbit, such as when they are aboard the space station Mir, the earth1s magnetic field offers much less protection. A violent solar eruption emits particles that can penetrate the walls of a spacecraft. For example, several times since the 1980s, cosmonauts aboard Mir received more radiation during a brief flareup than most people receive in a year."
Adds Vazquez, "Besides increasing our knowledge about the effects of cosmic radiation on humans and materials, these studies have the potential for enhancing our knowledge of the structure and repairability of genetic material, and for increasing our understanding of the link between ionizing radiation and such biological effects as cancer, aging and neurodegeneration."
In addition to the current research on biological and industrial samples at Brookhaven, future experiments may involve other materials that could be used to develop radiation-hardened "smart" circuits for space computers. If a smart circuit received a potentially damaging hit from a charged particle, it would "know" to pass its function on to a backup circuit.
NASA is also building a permanent structure at Brookhaven called the Booster Application Facility, an adjunct to the AGS where radiobiology experiments could be performed year-round.
The U.S. Department of Energy's Brookhaven National Laboratory
creates and operates major facilities available to university,
industrial and government personnel for basic and applied research
in the physical, biomedical and environmental sciences, and in
selected energy technologies. The Laboratory is operated by Brookhaven
Science Associates, a not-for-profit research management company,
under contract with the U.S. Department of Energy.