Scientist at the European Space Agency (ESA) are now thinking that the cause of last week’s Schiaparelli lander crash and destruction, was more than likely down to a computer glitch than some form of catastrophic mechanical failure.
Anyone in any doubt of the fate of the ExoMars lander only need take one look at the photograph NASA released late last week showing what appears to be a churned crater and the remains of the probe’s parachute lying on the red planet’s surface.
According to ESA, all available evidence so far points to a series of software errors as a reason for the untimely demise of the probe, part of whose mission, ironically, was to test its suitability for landing rovers on future missions to Mars.
Schiaparelli’s descent from orbit seems to have gone perfectly to begin with, with the lander entering and travelling through Mars atmosphere and deploying its parachute as planned. ESA researchers will probably take little comfort in the fact that for five minutes of the planned six-minute descent, everything went exactly as planned.
In the final moments of the probe’s drop to the surface however, things started to go wrong. While evidence points to cascading computer failures as the main fault, no one as yet seems to know exactly why Schiaparelli seems to have ejected its heatshield ahead of schedule and instead of firing its thrusters for a 30 second burn, engaged them for a mere 3 seconds before shutting them off.
The thinking at ESA headquarters is that Schiaparelli’s on board systems miscalculated its proximity to the surface. This theory is borne out by the fact that the probe began to switch on instruments and sensors it was supposed to use during its mission.
In real terms, however, rather than being a few metres off the ground, Schiaparelli was in fact still over a mile away from touching down, and therefore hit the surface at high enough speed to virtually obliterate the lander and form a large crater.
The ExoMars team responsible for the lander have until 2020 to find and fix the problem when the next, larger, version of the ExoMars probe, complete with rover, is due to take off.