Images taken by by NASA’s Mars Reconnaissance Orbiter (MRO) have provided new details about the area where the ExoMars Schiaparelli module ended up following its descent to the surface of the Red Planet on 19th October. Schiaparelli entered the martian atmosphere at 14:42 GMT on 19 October for its 6-minute descent to the surface, but contact was lost shortly before expected touchdown. Data recorded by its mothership, the Trace Gas Orbiter, are being analysed to understand what happened during the descent sequence.
The latest image was taken on 25th October by MRO’s high-resolution camera on NASA’s Mars Reconnaissance Orbiter and provides close-ups of new markings on the planet’s surface first found by the spacecraft’s low-resolution CTX “context camera” a few days earlier, on 20th October.
Both cameras had already been scheduled to observe the centre of the landing ellipse after the coordinates had been updated following the separation of Schiaparelli from ESA’s Trace Gas Orbiter on 16 October. The separation manoeuvre, hypersonic atmospheric entry and parachute phases of Schiaparelli’s descent went according to plan, the module ended up within the main camera’s footprint, despite problems in the final phase.
The main feature of the context images was a dark fuzzy patch of roughly 15 x 40m, associated with the impact of Schiaparelli itself. The high-resolution images show a central dark spot, 2.4m across, consistent with the crater made by a 300kg object impacting at a few hundred km/h.
Estimates are that Schiaparelli dropped from a height of between 2 and 4 kilometres, therefore impacting at a considerable speed, greater than 300km/h. The relatively large size of the feature would then arise from disturbed surface material. It is also possible that the lander exploded on impact, as its thruster propellant tanks were likely still full. These preliminary interpretations will be refined following further analysis.
Meanwhile, the teams continue to decode the data extracted from the recording of Schiaparelli descent signals recorded by the ExoMars TGO in order to establish correlations with the measurements made with the Giant Metrewave Radio Telescope (GMRT), an experimental telescope array located near Pune, India, and with ESA’s Mars Express from orbit.
The ExoMars TGO orbiter is currently on a 101,000km x 3,691km orbit (with respect to the centre of the planet) with a period of 4.2 days, well within the planned initial orbit. The spacecraft is working very well and will take science calibration data during two orbits in November 2016.
It will then be ready for the planned aerobraking manoeuvres starting in March 2017 and continuing for most of the year, bringing it into a 400km altitude circular orbit around Mars.
The TGO will then begin its primary science mission to study the atmosphere of Mars in search of possible indications of life below the surface, and to act as a telecommunications relay station for the ExoMars 2020 rover and other landed assets.