Waiting for ExoMars lander to re-establish a connection
20 October 2016
The Trace Gas Orbiter (TGO) of ESA's ExoMars 2016 successfully performed the 139-minute burn required to be captured by Mars but has signal been lost?
TGO's Mars orbit Insertion burn lasted from 13:05 to 15:24 UTC on 19 October, reducing the spacecraft's speed and direction by more than 1.5km/s. The TGO is now on its planned orbit around Mars. European Space Agency teams at the European Space Operations Centre (ESOC) in Darmstadt, Germany, continue to monitor the good health of their second orbiter around Mars, which joins the 13-year old Mars Express.
The ESOC teams tried to confirm contact with the Entry, Descent & Landing Demonstrator Module (EDM), Schiaparelli, which entered the Martian atmosphere some 107 minutes after TGO started its own orbit insertion manoeuvre.
The 577kg EDM was released by the TGO at 14:42 UTC on 16 October. Schiaparelli was programmed to autonomously perform an automated landing sequence, with parachute deployment and front heat shield release between 11 and 7km, followed by a retrorocket braking starting at 1100m from the ground, and a final fall from a height of 2m protected by a crushable structure.
Prior to atmospheric entry at 14:42 UTC, contact via the Giant Metrewave Radio Telescope (GMRT), the world's largest interferometric array, located near Pune, India, was established just after it began transmitting a beacon signal 75 minutes before reaching the upper layers of the Martian atmosphere. However, the signal was lost some time prior to landing.
A series of windows have been programmed to listen for signals coming from the lander via ESA'S Mars Express and NASA's Mars Reconnaissance Orbiter (MRO) and Mars Atmosphere & Volatile Evolution (MAVEN) probes. The Giant Metrewave Radio Telescope (GMRT) also has listening slots.
If Schiaparelli reached the surface safely, its batteries should be able to support operations for three to ten days, offering multiple opportunities to re-establish a communication link.
TGO is equipped with a suite of science instruments in order to study the Martian environment from orbit. Although mostly a technology demonstrator, Schiaparelli is also carrying a small science payload to perform some observations from ground.
ExoMars 2016 is the first part of a two-fold international endeavour conducted by ESA in cooperation with Roskosmos in Russia that will also encompass the ExoMars 2020 mission. Due in 2020, the second ExoMars mission will include a Russian lander and a European rover, which will drill down to 2m underground to look for pristine organic material.
NASA’s Mars Reconnaissance Orbiter has identified new markings on the surface of the Red Planet that are believed to be related to ESA’s ExoMars Schiaparelli entry, descent and landing technology demonstrator module.
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 currently being analysed to understand what happened during the descent sequence.
In the meantime, the low-resolution CTX camera on-board the Mars Reconnaissance Orbiter (MRO) took pictures of the expected touchdown site in Meridiani Planum on 20 October as part of a planned imaging campaign.
The image released today has a resolution of six metres per pixel and shows two new features on the surface when compared to an image from the same camera taken in May this year.
Estimates are that Schiaparelli dropped from a height of 2-4km, 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.