2001 Mars Odyssey

Launch Date: April 7, 2001
Arrival Date: October 24, 2001
Mass: 758 kilograms (1,671 pounds), fueled
Science instruments on board: Mars Radiation Environment Experiment (MARIE), Thermal Emission Imaging System (THEMIS) and Gamma Ray Spectrometer (GRS)

2001 Mars Odyssey is an orbiting spacecraft. One of its main objectives is to determine the composition of the planet's surface. Although the surface of Mars has long been thought to consist of a mixture of rock, soil and icy material, the exact composition of these materials is still unknown. The spacecraft will collect images that will be helpful in identifying the minerals present in the soils and rocks on the Martian surface and to study small-scale geologic processes.

By measuring the amount of hydrogen found in the upper meter of soil across the whole planet, the spacecraft will help us understand how much water may be available for future exploration, as well as give us clues about Mar's climatic history. Mars Odyssey will also collect data on the radiation environment of Mars to help the scientists assess potential risks to any future human explorers to Mars. The orbiter can also act as a communications relay for future Mars landers.