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NASA's MAVEN spacecraft closing in on Mars

Irene Klotz, Spaceflight Correspondent
Sep 19, 2014, 10:21 UTC

Sen—NASA’s MAVEN spacecraft is due to end its 10-month, 442 million-mile journey to Mars Sunday night with a do-or-die braking burn to put itself into orbit.

The 33-minute engine firing is expected to start at 9:37 p.m. EDT. If successful, MAVEN will end up in an elliptical, 35-hour orbit that comes as close as 236 miles and as far away as 27,713 miles from the planet’s surface. 

Over the next six weeks, engineers will configure MAVEN’s science instruments and maneuver the spacecraft into its planned operational 4.5-hour orbit, with an apogee of 3,853 miles and a perigee as close as 93 miles. 

From that vantage point, MAVEN will study how the solar wind and other phenomena are interacting with gases in Mars’ upper atmosphere. Scientists suspect that the planet once had a much thicker atmosphere, which would have enabled liquid water to pool on its surface. 

Previous missions have found convincing evidence of river channels, lakebeds and chemical signs of past water. The planet today, however, is a cold and dry desert. 

“Where did the water go? Where did the CO2 go from that early environment?” said University of Colorado Mars scientist Bruce Jakosky, lead researcher for the MAVEN mission.

“It can go two places,” he said. “Down in the crust or up to the top of the atmosphere where it can be lost to space.”

MAVEN—an acronym for Mars Atmosphere and Volatile Evolution—is designed to explore the latter option.

“This is the first mission to study Mars’ upper atmosphere, explore the climate history,” said Lisa May, who oversees the program at NASA Headquarters in Washington DC.

By studying what is happening to the atmosphere today, scientists expect to learn about the processes and then use computer models to extrapolate back in time. 

“Many processes may have been at work,” Jakosky said. “The question is whether over long periods of time … (they) have been responsible for removing a lot of the gas.”

Ultimately, scientists hope to learn more about whether Mars had the right conditions for life to evolve. 

“Life by itself is not easy to identify. It’s not  easy to understand. We’re trying to understand the context in which life might have existed,” Jakosky said.

MAVEN’s prime mission is expected to last a year, though extensions likely will be requested. After the science mission is over, MAVEN will be transitioned into a data relay satellite, linking rovers and landers on the surface to mission control centers back on Earth.