NASA’s next big mission will be the launch and landing of the Mars 2020 rover on the surface of the Red Planet. To support that mission, an existing NASA spacecraft is changing its orbit. That spacecraft is MAVEN, Mars Atmosphere and Volatile Evolution. MAVEN is currently on a new mission preparing to get new responsibility as a data relay satellite for the Mars 2020 rover.
That rover launches next year, and NASA is already saying that MAVEN could be used to relay information back from future rover missions as well. The new orbit of MAVEN won’t be drastically shorter than its present orbit, but the small change will have a significant impact on communications capability.
NASA’s Bruce Jakosky, MAVEN principal investigator, says that it’s like using a cell phone in that the closer to the tower, the better your signal. The shorter MAVEN orbit will also see the satellite orbit more times per Earth day at 6.8 orbits per day compared to the 5.3 per day in its previous orbit.
NASA has had great success with MAVEN; it was initially only meant to last two years in space. As of now, MAVEN is still operating, and NASA says it has enough fuel to continue through 2030. NASA will use the relay capability of MAVEN as long as possible.
Mission controllers will use something called aerobraking that leverages drag in the upper atmosphere of Mars to slow MAVEN down, orbit by orbit. The orbit us being carefully changed over a couple of days by firing the thrusters of the spacecraft. Using the atmosphere to slow saves fuel, and allows MAVEN to operate longer.