Model of the descent vehicle Sciaparelli on the background of representatives of the European Space Agency, who explain its accident. Photo: Kai Pfaffenbach / Reuters

Photographs of a pile of Martian soil at the landing site of the Schiaparelli descent vehicle left little room for doubt. The apparatus of the European Space Agency, which was supposed to work out a new technology of soft landing, crashed into the surface and, possibly, exploded.

The sad events of October 19, 2016 were a painful blow, but ESA engineers again and again revive Schiaparelli in a computer simulation, trying to understand the reasons for the failure.

The Schiaparelli was an integral part of the Exomarss spacecraft launched on March 14, 2016 from Baikonur.
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Installation and installation of the complex on Proton-M

It separated from the orbital module " Trace Gas Orbiter " (TGO) when approaching Mars on October 16 at 14:42 UTC.

Chronicle of the accident

Soft landing program. Illustration: ESA

On October 19, Schiaparelli entered the atmosphere of Mars at a speed of 21,000 km / h. Within 3-4 minutes the speed was reduced by aerodynamic braking. The heat shield in the frontal part slowly melted and evaporated. At an altitude of 11 km, when the speed dropped to 1,700 km / h, a parachute turned over the Schiaparelli, and after 40 seconds the frontal part of the protective casing with a heat shield was dropped.

Unlike the Beagle-2 landing module, which was lost during landing on December 25, 2003, the Schiaparelli continued to send telemetry to the orbiter during descent.

It is assumed that the parachute descent went smoothly, but approximately 50 seconds before the expected landing, the signal from the Schiaparelli disappeared .

On October 21, ESA recognized the probe as lost. After analyzing the TGO telemetry, engineers put forward a version that, perhaps, the parachute shooting occurred a little earlier than planned, and the soft landing engines could shut down at too high an altitude.

The on-board computer turned off the engines

Landing should have lasted almost 6 minutes. Research manager of the project “Exomarse” Jorge Vago (Jorge Vago) said that the first problems started 4 minutes 41 seconds after entering the atmosphere. The ejection of the parachute and protective casing occurred ahead of time, and the landing engines, which were supposed to turn on for the last 30 seconds before landing, worked for only 3 seconds. After that, the unit turned off the engines, because the on-board computer decided that the landing was complete.

The on-board computer not only turned off the engines after a “successful landing”, but also activated the work of scientific instruments on board the apparatus, preparing to perform work tasks of studying the weather on the surface: measure the electric fields and the concentration of atmospheric dust. “I guess at that moment we were still too high. And the most likely scenario is that then we just fell to the surface, ”said Vago.


Photos before and after landing of the Schiaparelli, made by the Mars Reconnaissance Orbiter. Photo: NASA / JPL-Caltech / MSSS

Judging by the size of the impact crater at the site of the alleged Schiaparelli fall (15–40 m), it fell from a height of 2–4 km and collided with the surface at a speed of more than 300 km / h.

It is too early to draw final conclusions, so that ESA engineers only speculate. The head of ESA's solar and planetary missions, Andrea Accomazzo, says that the cause of a computer error is related either to a software error or to the compatibility problem of heterogeneous data from different sensors.

Work on the mistakes before the "Exomars 2020"

The program "Exomarso-2016" European Space Agency organized in conjunction with the "Roskosmos". It precedes the mission "Exomars 2020", when scientists hope to land on the surface of a larger research station and the rover. There, during landing, the same sensors and software will be used as that of Schiaparelli, of Russian and European origin.


Mars rover "Exomars-2020". Illustration: ESA

Andrea Akomazzo believes that if the problem is in the software error and sensors, then it will be relatively easy to fix. Judging by the preliminary data, the hardware of the descent module worked fine. Both the parachute and the heat shield and the engines were tested and worked in real conditions. Probably, the problem is only in management. Akomazzo said that before the launch of 2020, the equipment was thoroughly rechecked.

But the most important thing is to find the source of a program error, if there is a reason for it. For this, a group of engineers uses a virtual landing simulator of the descent vehicle.

The second part of the mission “Exomars” was already transferred from 2018 to 2020, so no one wants to shift it for another two years. The project already has a financing gap of about € 300 million. The problem will be solved at a meeting of EU ministers in December 2016. If Schiaparelli made a soft landing, it would be much easier to convince the ministers. On the other hand, after all, the probe showed itself quite well. He worked perfectly and transmitted data until he fell. There are no complaints at all on the orbiter “Trais Gas Orbiter”: from December 2017 it will begin to study the Martian atmosphere for biological and geological sources of methane. It will also work as a communications hub for the rover in 2020. So, with some exceptions, the mission “Exomars-2016” can be considered successful.

In the end, the Schiaparelli was a test module. It is much better to break the test module than the expensive rover. And who in general can imagine space expeditions without accidents? Currently, only NASA vehicles are operating on the surface of Mars. If Russia and ESA want to join, then the only opportunity is to take a chance in 2020.


The rover "Exomars-2020" with the scientific complex Pasteur. Illustration: ESA