Space radiation is bad for your health. Everyone has known that since the 1950s when scientists first started talking about human space travel. But no one is certain of the best ways to protect interplanetary space crews from cosmic radiation.

The challenge of finding out is being added to the role of materials scientists who previously had been using the space environment as a tool to explore the nature of matter. Last week, at the 1998 Microgravity Materials Sciences Conference in Huntsville, a small group of scientists discussed how to use materials in space to make space exploration safer.

The problem is not new. As early as 1952, Dr. Wernher von Braun and other space visionaries suggested using lunar soil to protect a manned expedition from space radiation and meteors.

But how much is enough? And what do you use for protection on the way out and back?

"The problem is that we need to figure out what needs to be improved," said Dr. Jim Adams of the Naval Research Laboratory in Washington. Although space radiation has been measured extensively since the 1950s, its intensity changes, and our knowledge of how it reacts with materials still lags in many areas.

Adams and several other scientists discussed directions research takes. Current materials work in this field, in support of NASA's Human Exploration and Development of Space (HEDS) initiative, was started under an NRA released in December 1996.

One of the problems in radiation shielding is that a little can be worse than none. Radiation actually comprises electromagnetic radiation - X-rays and gamma rays - and particulate radiation - high-speed particles like electrons, protons, neutrons, and atomic nuclei. Low-energy radiation can be stopped by a spacecraft wall, but at higher energies the wall helps produce showers of secondary radiation, like splinters from a wall hit by a bullet. So, even more shielding is needed to absorb that, until
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Contact: Tim Tyson
tim.tyson@msfc.nasa.gov
256 544 0994
NASA/Marshall Space Flight Center--Space Sciences Laboratory
20-Jul-1998