As evidence mounts that water once flowed on the surface of now-arid Mars, scientists hope Maven will help them understand why the red planet dried out.
"Something clearly happened," the University of Colorado's Bruce Jakosky, the principal Maven scientist, said Sunday, according to a statement. "What we want to do is to understand what are the reasons for that change in the climate."
The Maven, which NASA describes the explorer as an eight-foot cube weighing about as much as an SUV flanked by "gull-wing-shaped" solar panels, is set to reach Mars' atmosphere on Sept. 22, 2014.
Watch video of the liftoff below, courtesy of NASA: