Mars' loss of its protective magnetic field may have triggered the loss of its atmosphere.
Maven is part of NASA's low-cost Mars Scout program.
Mars Phoenix was the first Mars Scout mission.
The spacecraft, measured wingtip to wingtip, is about the same length as an average school bus.
MAVEN weighs about the same as a fully loaded (people and cargo) SUV, which is about 2,550 kg (5,622 lbs).