By the middle of next week, NASA’s Mars Odyssey orbiter will have worked longer at Mars than any other spacecraft in history. Odyssey made its most famous discovery — evidence for copious water ice just below the dry surface of Mars — during its first few months, and it finished its radiation-safety check for future astronauts before the end of its prime mission in 2004. The bonus years of extended missions since then have enabled many accomplishments that would not have been possible otherwise.