Mars Atmosphere and Volatile Evolution (MAVEN) is a space probe designed to study the Martian atmosphere while orbiting Mars. Mission goals include determining how the Martian atmosphere and water, presumed to have once been substantial, were lost over time.
MAVEN was successfully launched aboard an Atlas V launch vehicle at the beginning of the first launch window on November 18, 2013. Following the first engine burn of the Centaur second stage, the vehicle coasted in low-Earth orbit for 27 minutes before a second Centaur burn of five minutes to insert it into a heliocentric Mars transit orbit.
The plan is for MAVEN to be inserted into an orbit around Mars: an areocentric elliptic orbit 6,200 km (3,900 mi) by 150 km (93 mi) above Mars' surface, on September 22, 2014. The principal investigator for the spacecraft is Bruce Jakosky of the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder.
Features on Mars that resemble dry riverbeds and the discovery of minerals that form in the presence of water indicate that Mars once had a thicker atmosphere and was warm enough for liquid water to flow on the surface. ?Scientists suspect that over millions of years, the planet’s core cooled and its magnetic field decayed, allowing the solar wind to sweep away ninety-nine percent of the atmosphere and thus most of its water and volatile compounds.
MAVEN is intended to determine the history of the loss of atmospheric gases to space so that answers about Martian Climate evolution will emerge. From its measurements of how quickly the atmosphere escapes into space and the relevant processes, scientists will infer how the planet's atmosphere evolved. The MAVEN mission has four primary scientific objectives:
1.?Determine the role that loss of volatiles to space from the Martian atmosphere has played through time.
2.?Determine the current state of the upper atmosphere, ionosphere, and interactions with the solar wind.
3.?Determine the current rates of escape of neutral gases and ions to space and the processes controlling them.
4.?Determine the ratios of stable isotopes in the Martian atmosphere.
MAVEN is expected to reach Mars in September 2014. By then, the Sample Analysis at Mars (SAM) instrument suite on board the Curiosity rover will have made similar surface measurements from Gale crater, which will help guide the interpretation of MAVEN's upper atmosphere measurements. MAVEN's measurements will also provide additional scientific context with which to test models for current methane formation in Mars.http://en.wikipedia.org/wiki/MAVEN