2001 Mars Odyssey is a robotic spacecraft orbiting the planet Mars. The project was developed by NASA, and contracted out to Lockheed Martin, with an expected cost for the entire mission of US$297 million. Its mission is to use spectrometers and a thermal imager to detect evidence of past or present water and ice, as well as study the planet's geology and radiation environment. The data Odyssey obtains is intended to help answer the question of whether life once existed on Mars and create a risk-assessment of the radiation that future astronauts on Mars might experience. It also acts as a relay for communications between the Curiosity rover, and previously the Mars Exploration Rovers and Phoenix lander, to Earth.

Wikipedia: https://en.wikipedia.org/wiki/2001_Mars_Odyssey. Related NASA reference: https://nssdc.gsfc.nasa.gov/planetary/chronology.html#2001. Description adapted from Wikipedia contributors (CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/).