Mars once had a denser atmosphere that supported the presence of liquid water on the surface. As part of a dramatic climate change, most of the Martian atmosphere was lost. MAVEN mission will explore the Red Planet's upper atmosphere, ionosphere and interactions with the sun and solar wind.

Scientists will use MAVEN data to determine the role that loss of volatile compounds—such as carbon dioxide, nitrogen dioxide, and water—from the Mars atmosphere to space has played through time, giving insight into the history of Mars' atmosphere and climate, liquid water, and planetary habitability.

This mission is under the responsibility of a general Principal Investigator, Bruce Jakosky (LASP, Boulder), and a Deputy-PI, Robert P. Lin (SSL, Univ. Berkeley).

Eight scientific instruments will equip the satellite:

Neutral Gas and Ion Mass Spectrometer (NGIMS), which Instrument Lead is Paul Mahaffy, Goddard Space Flight Center
Imaging Ultraviolet Spectrometer (IUVS), which Instrument Lead is Nick Schneider, LASP
The instrument suite Particle and Field Package (PFP), which Instrument Lead is Robert Lin, is composed of the following instruments:

Magnetometer (MAG), which Instrument Lead is Jack Connerney, Goddard Space Flight Center
Solar Wind Electron Analyzer (SWEA), which Instrument Lead is David Mitchell, SSL ; instrument for which CESR in Toulouse (Resp.: Christian Mazelle), will provide all the instrument except the digital part linked to the DPU (Digital Processing Unit)
Solar Wind Ion Analyzer (SWIA), which Instrument Lead is Jasper Halekas, SSL
Solar Energetic Particles (SEP), which Instrument Lead is Davin Larson, SSL
SupraThermal And Thermal Ion Composition (STATIC), which Instrument Lead is Jim McFadden, SSL
Langmuir Probe and Waves antenna (LPW), which Instrument Lead is Bob Ergun, CU-LASP

CNES insures, for all national partners (laboratories), the prime contractorship for the French instrument contributions to MSL.