HR: 12:05h
AN: P21C-08 INVITED     [PDF]
TI: Results from the Martian Radiation Environment Experiment
AU: * Zeitlin, C
EM: cjzeitlin@lbl.gov
AF: National Space Biomedical Research Institute, One Baylor Plaza, Houston, TX 77030 United States
AU: Cleghorn, T F
EM: timothy.f.cleghorn1@jsc.nasa.gov
AF: NASA Johnson Space Center, NASA Road One, Houston, TX 77-58 United States
AU: Cucinotta, F A
EM: francis.a.cucinotta1@jsc.nasa.gov
AF: NASA Johnson Space Center, NASA Road One, Houston, TX 77-58 United States
AU: Saganti, P
EM: premkumar.saganti1@jsc.nasa.gov
AF: NASA Johnson Space Center, NASA Road One, Houston, TX 77-58 United States
AB: Ionizing radiation in space presents a potentially serious health hazard to astronauts on long-duration missions outside the geomagnetosphere. As a precursor to possible human exploration, the Martian Radiation Environment Experiment, MARIE, is returning the first detailed radiation data from Mars. MARIE is designed to measure the nearly constant flux of energetic Galactic Cosmic Rays (GCR) and intermittent Solar Particle Events (SPE). Despite considerable uncertainties in the normalization of MARIE data, comparisons to model calculations show good agreement, well within the estimated errors. The radiation dose equivalent on Mars from GCR is predicted to be 0.2 - 0.3 Sieverts/yr. (This is approximately 1000 times higher than the cosmic ray dose received on Earth.) In Mars orbit, over the first 16 months of operation, MARIE data show an annual dose equivalent of 0.4 +- 0.1 Sv/yr. That the measured rate is higher than the calculation is expected, since in orbit there is a contribution from low-energy particles that do not survive transport through the atmosphere. Additionally, SPE during this period have contributed about 0.04 Sv/yr to the average annual dose equivalent, a figure that can vary substantially over the course of the solar cycle. The implications of these data for human exploration will be discussed.
DE: 2104 Cosmic rays
DE: 2118 Energetic particles, solar
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting