Space Radiobiology

A Collaborative Project sponsored by the NASA Space Radiation Health Program
BNL Participants: Medical Dept. (Marcelo Vazquez), Collider-Accelerator Dept., Biology Dept. (Betsy M. Sutherland)

Manned space exploration in the 21st century holds exciting prospects for the advancement of science and the expansion of the human experience. Plans include the Alpha space station, an outpost on the Moon, exploration of near asteroids, and a piloted mission to Mars. However, for space exploration to go on, human crew members must be protected against the harsh environment of space, in particular, against the hazards of ionizing radiation. The radiation environment in space consists of high energy protons and high energy heavy ions (HZE).

The principal source of HZE ions in nature is galactic cosmic rays (GCR), which consist mostly of protons, with small components of helium and heavier nuclei, electrons and positrons. Although the GCR will be attenuated and fragmented by electromagnetic and nuclear interactions in shielding material, crew members will still be exposed to significant radiation from both primary and secondary nuclei.

NASA-BNL-AGS Program

Research supported by NASA on the radiobiological effects of high energy heavy ions had been carried out for several years at the Lawrence Berkeley National Laboratory BEVALAC in California. With the closing of the BEVALAC, the Brookhaven National Laboratory (BNL) Alternating Gradient Synchrotron (AGS) is the only accelerator in the United States capable of providing heavy ion beams at energies of interest for space radiobiology. Facilities in Europe, Russia and Japan are available, but their use is severely limited by a number of factors, including the lack of logistic support, the difficulty of shipping test biological samples over very long distances, and limited and/or very expensive beam time.

NASA/AGS Heavy Ion Experiments

During the Fall of 1995, an initial group of experiments in radiobiology was performed using a beam of 1 GeV/amu 56Fe ions from the AGS. These experiments were sponsored and funded by NASA as part of the Space Radiation Health Program (SRHP). The SRHP is a peer-reviewed basic and applied research program relating to the effects on humans of space radiation, with the ultimate goal of providing a firm scientific basis for space radiation protection. These experiments address the particular problem of high energy heavy ion radiation exposures during future long-term deep space flights. Their principal objective is to improve our understanding of the biological effects of low fluences of densely ionizing charged particles on living cells and tissues. Humans themselves are not subjects for irradiation in these tests. These experiments are continuing with external investigators from universities, national laboratories, and research institutes, including both US and international investigators.

NASA Space Radiation Laboratory

The NASA Space Radiation Laboratory (NSRL), a $34-million facility, jointly managed during a four-year construction project by the DOE’s Office of Science and NASA’s Johnson Space Center, is one of the few places in the world that can simulate the harsh cosmic and solar radiation environment found in space. The facility, opened in 2003, employs beams of heavy ions extracted from Brookhaven’s Booster accelerator, the best in the United States for radiobiology studies. The NASA Space Radiation Laboratory features its own beam line dedicated to radiobiology research, as well as state-of-the-art specimen-preparation areas. More details about NSRL...