Launched last April, Mars Odyssey will map and analyze the elemental composition of the Martian surface to find evidence of water. Previous Mars missions were only able to find evidence of water on local levels. Odyssey will be able to determine whether water exists on a global scale.

Odyssey landed on Mars on Oct. 24. A few days after its arrival, Odyssey began to use its solar panels to begin aerobraking, a maneuver in which a spacecraft skims the top of a planet’s atmosphere. The friction of the atmosphere against the solar panels helps slow the spacecraft until it achieves a circular orbit around Mars. Once final orbit has been reached in late January, Odyssey can start its primary missions.

Odyssey will measure the amount of hydrogen under the surface of Mars using its gamma ray spectrometer. Hydrogen concentrations can help determine the location of water, which will help future human explorations. The gamma ray spectrometer will also measure amounts of other elements, such as potassium, sodium and thorium. Data gathered from the gamma ray spectrometer can be used to create a geological history of Mars. The information can also be used to find the locations of extinct lakebeds and sea floors.

The spacecraft will also take pictures of Mars using its thermal emission imaging system. The system will use infrared imaging to identify minerals on the surface of Mars. Thermal emission imaging system data can be used to find future landing sites. The system also will help the gamma ray spectrometer in locating ancient lakebeds.

The Mars radiation environmental experiment located on board Odyssey will measure radiation amounts in the Mars vicinity. Information about radiation levels will reveal potential threats to future human explorers.

Odyssey’s primary missions are slated to be complete by July 2004. It will remain in orbit around Mars to provide a relay of information for future Mars landers and rovers.