NASA's Mars Science Laboratory is currently readying a new satellite to investigate Mars' atmosphere -- or, more to the point, lack of atmosphere -- in a mission slated to launch next year.
The Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter will attempt to discover how Mars went from a planet with an atmosphere full of CO2, nitrogen dioxide, water vapor and more to a planet without much of an atmosphere at all.
The goal of MAVEN is to determine the role that loss of atmospheric gas to space played in changing the Martian climate through time. Where did the atmosphere – and the water – go?
MAVEN is currently on time and on budget (a NASA rarity) and scheduled to launch in November 2013 and reach Mars in September 2014.