To Unlock Mars's Wet Past, NASA's Next Orbiter Will Scan the Martian Sky

When it comes to Mars, we typically get more excited about landers and rovers than orbiters. But there’s an orbiter mission launching later this year that’s going to be awesome: MAVEN (Mars Atmosphere and Volatile EvolutioN) is going to tell us how the Martian atmosphere and environment has evolved over the planet’s lifetime. The data the school bus sized spacecraft gathers will enable the science team to accurately model ancient Mars and, they hope, make some unexpected discoveries.

MAVEN's mission is to sample Mars’s remaining atmosphere, gathering data that will help the science team draw conclusions about the planet’s more-hospitable-for-life past. We know that Mars once had a denser atmosphere that supported liquid water on the surface and that that water and most of the Martian atmosphere was lost when the climate changed. MAVEN is going to help us understand why.

Dave Brain, one of the MAVEN science team co-investigators, used this analogy to explain the mission: Think of Mars as a pot of water. You turn the burner on high and and get the pot boiling, and then turn the heat down so the water isn’t actively boiling anymore but there’s still steam coming off the pot. After getting into your mini spacecraft, you fly through the steam taking measurements, and from that data you draw conclusions about the water before it boiled.

Of course, there’s more to Mars’s story than a hot planet that cooled and went from wet to dry. Compared to Earth, there’s its lack of global magnetic field, the existence of localized crustal magnetic fields, the planet’s overall smaller size, and past periods of heavy bombardment (imagine the steaming pot of water experiment with a ladle coming out of nowhere and scooping out some of the water).

MAVEN is a NASA mission, but the science team backing the spacecraft comes from a host of sites—NASA’s Goddard Spaceflight Centre, JPL, University of California at Berkeley, Lockheed Martin, and the University of Colorado Boulder’s Laboratory for Atmospheric and Space Physics (LASP). And this past weekend, LASP invited a small cohort of new media practitioners to Boulder to learn about MAVEN right from the science team. After attending and hearing the project discussed in-depth, I think this mission is going to be pretty awesome.

MAVEN’s mission is complicated but will offer an important look at the planet's history. So why we haven’t seen an atmospheric mission launched to Mars in the past? The formal term for an atmospheric mission is aeronomy, which includes the study of ionization and the behavior of isotopes in the upper atmosphere. According to Michael Meyer, lead scientist of NASA's Mars Exploration Program, there's nothing sexier sounding than an aeronomy mission.

But in this case sex doesn’t sell. Aeronomy just isn’t as exciting as a landing mission and, as project scientist Joe Grabowski suspects, we haven’t launched an atmospheric mission to Mars because we can see the planet’s surface and that has been a real distraction. The MAVEN team actually went so far as to keep the word “aeronomy” out of the original mission proposal, focusing instead on geology and atmosphere.

When it reaches Mars in the fall of 2014, MAVEN will use its propulsion system to enter an elliptical orbit ranging 90 to 3,870 miles above the planet. Using its suite of eight instruments, the spacecraft will take measurements throughout its primary mission, which is scheduled to last for one Earth year.

The science team is hopeful that within three months of the orbiter's arrival at Mars they will have retrieved enough good data to make at least a preliminary model of ancient Mars and its climate. In that full year of the primary mission, they should get a solid look at Mars's atmospheric makeup. MAVEN has enough fuel to last a decade, which means it’s likely the mission will be extended after that first year.

The MAVEN spacecraft has a secondary capability: it can serve as a relay satellite for robotic missions on the Martian surface. This is a useful capability, particularly with another rover on its way to Mars in 2020, but one the MAVEN team doesn’t want to exploit until the mission has accomplished its science goals. Any time the MAVEN spacecraft spends as a communications relay takes away from time spent gather the data it was designed for.

Right now, the MAVEN team is gearing up for the launch window that opens on November 18. They’re also working on coordinating with the European Space Agency whose Mars Express satellite is in orbit around the red planet right now. The MAVEN team hopes the ESA spacecraft will be able to gather supporting data, because when you’re doing something like backwards modeling a planet’s atmospheric history it’s good to have multiple vantage points.

The MAVEN team is calling the mission a once-in-a-career opportunity, but they hope they’re wrong about the once part. While they pitched a mission with clear science goals, they hope MAVEN will raise more questions than it answers, opening the door for more detailed orbiter missions.