ExoMars investigation discovered what went wrong with the mission on October 19 when the Mars lander crashed on the Red Planet surface. The saturation maximum measurement miscalculated an estimated altitude which triggered the Schiaparelli’s parachute and the backshell prematurely when the lander was still at an approximate altitude of 3.7 kilometers.
The investigation mentioned that the saturation maximum measurement of the Inertial Measurement Unit (IMU) had occurred soon after the lander’s parachute deployment. The IMU output behaved differently than was previously predicted. The erroneous information caused the crash.
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The IMU measures the rotation rates of the vehicle. The glitch made the Schiaparelli think that in was near the surface making it released the parachute and the backshell, a brief firing of the braking thrusters and the activation of the ground system even when it was kilometers away from Mars surface.
When investigating the Schiaparelli’s impact with the Red Planet, scientists discovered that the parachute deployed normally at an altitude of 12 km and a speed of 1730 km/h. The lander’s heat shield also deployed according to plan. The vehicle’s radar Doppler altimeter also functioned correctly -including the guidance, navigation and control system- according to the vast volume of data recovered from the Schiaparelli.
Apparently, what provoked the Mars lander crash was the activation of the braking thrusters and the activation of the on-ground systems. The information from the accident was reproduced in computer simulations of the control system’s response to the glitch, reported the European Space Agency (ESA).
David Parker, ESA’s Director of Human Spaceflight and Robotic Exploration, said the agency would continue to analyze data from the accident and stated that a final report would be available by 2017. An external independent inquiry board has been assigned as a request from ESA’s Director General under the chairmanship of ESA’s Inspector General.
Schiaparelli accident, first ExoMars mission, will help to improve the upcoming mission. Additionally, the Trace Gas Orbiter still works
The failed landing will serve future ExoMars missions to prevent the errors identified in the first task. Parker stated in the press release that Schiaparelli miscalculation will directly contribute to the upcoming mission going to Mars in 2020.
Even when the lander crashed, the mission collected -and continues to do so- significant data about Mars atmosphere and other features thanks to the Trace Gas Orbiter. The orbiter traveled to Mars along with the Schiaparelli lander and got separated from it at Mars orbit on October 19.
The Trace Gas Orbiter was designed to study the planet’s atmosphere since methane was discovered in it. Methane is a gas that could be evidence for possible biological or geological activity on the planet. Methane and other atmospheric gasses are concentrated in small quantities -less than one percent- in Mars. Still, the phenomena have to be investigated because if those gasses are up in the atmosphere, it means that the source is down on the planet’s surface or underground.
One of the orbiter’s mission is to find out if the origin of the methane is biological or chemical. On Earth, organisms release the gas as they digest nutrients. Geological processes, on the other hand, also release methane when certain minerals oxidize, for example.
The instruments on board the Trace Gas Orbiter were developed to clarify where the methane is coming from and what is originating it. The orbiter is a 400-km-altitude and can also detect water vapor, nitrogen oxides, and acetylene.
ESA explains that the Trace Gas Orbiter is also monitoring Mar’s seasons and how the changes affect the planet’s atmosphere. The information collected will be used to construct seasonal models of the Red Planet to better understand its nature.
The Trace Gas Orbiter will begin a long series of aerobraking maneuvers in the coming months that by the end of 2017 will set it on its intended operational orbit.
ExoMars next mission
ExoMars second mission is being developed with international partners, including the Agenzia Spaziale Italiana (ASI), which is the Italian Space Agency.
“Together with all the participating states in the program, we will work towards the successful completion of the second ExoMars mission. ESA and ASI’s strong partnership will continue to be instrumental in this valuable and exciting European mission.” Roberto Battiston, President of ASI stated.
Roscosmos, the Russian space agency is also collaborating in the second robotic exploration to Mars. The 2020 mission will be launch using a Proton rocket and the journey will last nine months. ExoMars 2020 will deliver and European rover and a Russian surface platform to the Red Planet.
The rover will search for signs of life, and according to ESA, it will be the first mission to combine the capability to move across the surface and to study Mars at depth. The European vehicle is equipped with a drill to collect and analyze samples with next-generation instruments.
The Trace Gas Orbiter will support communications for the next mission that will be controlled from Turin, Italy, at the Rover Operations Control Centre.
Source: ESA