The Martian Radiation Environment Experiment (MARIE) on the 2001 Mars Odyssey Spacecraft

Abstract

The 2001 Mars Odyssey spacecraft was launched to Mars on April 7, 2001, and reached Mars in late October 2001. Following arrival at Mars, a series of aero‐braking maneuvers were performed to place the spacecraft in a ∼400 km altitude orbit at Mars. One of the experiments on board the spacecraft is the Martian Radiation Environment Experiment (MARIE), which was designed to measure the galactic cosmic radiation (GCR) environment in the energy range from 20 − 500 MeV/u during the cruise phase to Mars and while in Mars orbit. The experiment is also capable of measuring solar particle events (SPE) in the same energy range. During the cruise phase a communication problem with the MARIE was encountered from early August until early March 2002 when communication was re‐established. In this paper the MARIE experiment is discussed in detail. The GCR measured data are compared with the GCR model environment. Several solar particle events that have been observed by MARIE are compared with the near‐Earth GOES satellite SPE data. These data represent a “first ever” GCR and SPE measurements in the vicinity of Mars and will be used to establish some guidelines for future human missions to Mars. The SPE data can also be utilized to compare with existing SPE interplanetary propagation models.