The DREAMS Experiment Onboard the Schiaparelli Module of the ExoMars 2016 Mission: Design, Performances and Expected Results

The first of the two missions foreseen in the ExoMars program was successfully launched on 14th March 2016. It included the Trace GasOrbiter and the Schiaparelli Entry descent and landing Demonstrator Module. Schiaparelli hosted the DREAMSinstrument suite that was the only scientific payload designed to operate after the touchdown. DREAMSis a meteorological station with the capability of measuring the electric properties of the Martianatmosphere. It was a completely autonomous instrument, relying on its internal battery for the power supply. Even with low resources (mass, energy), DREAMSwould be able to perform novel measurements on Mars ( atmospheric electricfield) and further our understanding of the Martianenvironment, including the dust cycle. DREAMSsensors were designed to operate in a very dusty environment, because the experiment was designed to operate on Mars during the dust stormseason (October 2016 in Meridiani Planum). Unfortunately, the Schiaparelli module failed part of the descent and the landing and crashed onto the surface of Mars. Nevertheless, several seconds before the crash, the module central computerswitched the DREAMSinstrument on, and sent back housekeepingdata indicating that the DREAMSsensors were performing nominally. This article describes the instrument in terms of scientific goals, design, working principle and performances, as well as the results of calibration and field tests. The spare model is mature and available to fly in a future mission.