Better Mars Atmosphere Maps to Come From New Mission

An instrument on one of the next missions to Mars is expected to beam back daily maps of the Martian atmosphere from orbit and seek out gaseous clues in the ongoing search for any evidence of life on the Red Planet. ?

The ExoMars Climate Sounder will measure pole-to-pole, vertical distributions of temperature, dust, water vapor and ice clouds in the Martian atmosphere. The instrument is one of five that have been selected for the ExoMars Trace Gas Orbiter mission ? a joint European-American operation, scheduled for 2016, that will seek faint gaseous signatures of potential life on Mars.

The atmospheric maps from the ExoMars Climate Sounder will provide daily profiles of the atmosphere's changing structure.

Multipurpose Mars tool

The international team of NASA and European Space Agency researchers building the new Mars orbiter has two main goals in addition to interpreting trace-gas detections.

One is to extend the climate mapping record that is currently coming from a similar instrument on NASA's Mars Reconnaissance Orbiter. That instrument, called the Mars Climate Sounder, has been working at the Red Planet since 2006.

The orbit of the Mars Reconnaissance Orbiter mission enables it to record atmospheric profiles only at about 3 p.m. and 3 a.m. during the Martian day, except near the poles. The ExoMars Trace Gas Orbiter, however, will fly an orbital pattern that allows the spacecraft to collect data at all times of the day, and at all latitudes.

"We'll fill in information about variability at different times of day, and we'll add to the number of Mars years for understanding year-to-year variability," said Tim Schofield, principal investigator for the ExoMars Climate Sounder at NASA's Jet Propulsion Laboratory in Pasadena, Calif., in a statement. "The most obvious year-to-year change is that some years have global dust storms and others don't. We'd like to learn whether there's anything predictive for anticipating the big dust storms, and what makes them so variable from year to year."

Another research goal is to provide information about the variable density of the atmosphere that could assist future landings on Mars. At any chosen landing site, atmospheric density has a tendency to change from one day to the next, which can greatly affect a spacecraft's descent.

"We want to provide background climatology for what to expect at a given site, in a given season, for a particular time of day, and also nearly real-time information for the atmospheric structure in the days leading up to the landing of a spacecraft launched after 2016," Schofield said.

The next generation

The ExoMars Climate Sounder is an infrared radiometer designed to operate continuously, day and night, from the spacecraft's orbit at about 250 miles (400 km) above the Martian surface.

The flexible instrument can pivot to point downward or toward the horizon, measuring temperature, water vapor, dust and ices for each 3-mile (5-km) increment in height throughout the atmosphere from ground level to 56 miles (90 km) in altitude.

The European Space Agency and NASA have selected five instruments for the ExoMars Trace Gas Orbiter. ESA will provide one instrument as well as the spacecraft. NASA will provide the other four instruments, including the ExoMars Climate Sounder, which is being constructed at JPL.

Mission objective

The 2016 ExoMars Trace Gas Orbiter is the first in a series of collaborative Mars missions between ESA and NASA.

A variable presence of small amounts of methane in the Martian atmosphere has been detected in orbital and Earth-based observations. A key goal of the mission is to gain a better understanding of methane and other trace gases that could be evidence of possible biological activity. Methane can be produced biologically and in environments void of life.

The ExoMars Trace Gas Orbiter will also serve as a communications relay for missions on the surface of Mars. It will also carry a European-built descent-and-landing demonstration module that is designed to operate for only a few days on the Martian surface.

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