No signal from Europe’s ExoMars experimental lander after touchdown
Image credit: European Space Agency
Everything was prepared for celebration at the European Space Agency control centre in the German town of Darmstadt, but after seven minutes of anticipation came concern as no signal arrived from the experimental lander Schiaparelli. ESA still has a reason to celebrate as the Trace Gas Orbiter, which carried the lander to Mars, successfully established itself in the orbit around the red planet.
The situation was reminiscent of the 2003 Beagle 2 mission. Back then, the scientists also listened, and listened, never to hear back. However, ESA director general Johann Woerner maintained the mission is indeed a success as the Trace Gas Orbiter was always meant to be the main element with Schiaparelli only a test, designed to pave the way for a safe landing of a rover in 2020.
“TGO is very successfully inserted into the orbit and is now ready for science and data relay, which we need for the 2020 mission. TGO is for us a cornerstone for the 2016 and 2020 mission,” Woerner said during a press briefing.
“The lander was a very complex manoeuvre, it was a very complex sequence. It was a test and we had many sensors on board to monitor each and every step of the process and these data was received by the mother ship.”
According to spacecraft operations manager Andrea Accomazzo, the preliminary analysis shows the EDM entered the atmosphere of Mars as expected and successfully used its heat shield to slow itself down during the first minutes of the atmospheric entry.
“We know it has gone through the upper layers according to our expectations. It has deployed the parachute as expected, the heat shield worked as expected, which was nominal and is critical to the 2020 mission. There is a moment where the parachute is released and this is when the data don’t match our expectations and following this phase, the lander did not behave as expected.”
He said it would take more time to piece together the complete picture of what actually went wrong.
“We have data from the lander but it will take some time to analyse all of that. ExoMars 2016 is oriented towards a multi-year science looking for traces of life, the relay station is established so we are really confident we have a basis for the 2020 mission,” he said.
Schiaparelli landing: how it should have worked:
The 577kg Schiaparelli lander, or Entry, Descent & Landing Demonstrator Module (EDM), was designed to test landing system for a rover mission set for launch in 2020. It also carries instruments for detecting signs of life.
Launched on 14 March this year from Russia’s Baikonour Cosmodrome in Kazakhstan, the lander travelled 496 million kilometres aboard the trace gas orbiter to reach the orbit of Mars. The two spacecraft separated on 16 October with TGO starting its manoeuvres to establish itself in the Martian orbit and Schiaparelli preparing for the challenging landing.
Landing on Mars is a tricky business. Only Nasa has managed to pull it off successfully – seven times. But even they still remain humble. The landing of Curiosity four years ago was publicised by Nasa as seven minutes of terror.
ESA was playing it calmer but still nervosity was palpable in the control room while waiting for the signals.
Schiaparelli, named after Italian astronomer Giovanni Virginio Schiaparelli, hit the upper layers of Martian atmosphere at the speed of 21 000 km per her. Within six minutes, it had to slow itself down to zero for a safe touch down using its heat-shield, a specially designed parachute and several rocket engines.
Although Martian atmosphere is much thinner than Earth’s, the spacecraft would still warm up to 1,500 °C. Once reaching Mach 2, the spacecraft would deploy the parachute. The final stage of the landing involves firing the rocket engines which were meant to slow down the lander to zero before it drops onto the planet’s surface.
The rover whose landing systems Schiaparelli was designed to test: