Assuming the $671m (£416m) mission stays on track, the probe will have a 10-month cruise to the Red Planet.
Maven is going to study Mars' high atmosphere, to try to understand the processes that have robbed the world of most of its air.
Evidence suggests the planet was once shrouded in a thick blanket of gases that supported the presence of liquid water at its surface. Today, the air pressure is so low that free water would instantly boil away.
Maven was released from the Atlas V's upper-stage some 53 minutes after leaving the Cape Canaveral pad. The probe then had to open its solar panels and orientate itself into a cruise configuration.
"Everything looks good. The signals are coming in fine, and so far the systems that are on are reporting back great. We're heading out to the Red Planet," confirmed David Mitchell, Nasa's Maven project manager.