European Space Agency officials say they still do not know what happened to their Mars lander, which made a parachute descent through the planet's thin atmosphere Wednesday, but stopped transmitting signals about 50 seconds before its intended touchdown.
But they haven't given up hope that the lander, known as Schiaparelli, survived the journey and will begin communicating from the surface of Mars before its batteries run out of power in a few days.
Even if Schiaparelli crashed, ESA says the mission accomplished its primary goal to relay engineering data about the risky entry and descent through the atmosphere.
Much of that information was picked up by Schiaparelli's mothership, the Trace Gas Orbiter, which put itself into orbit around Mars at about the same time the lander was coasting on its parachute.
"We have collected all the engineering data that (Schiaparelli) has produced. This is the most important thing. If you have a test, the test can go well, (or go) wrong, but the most important thing is to collect test data and this is what we have successfully done," Andrea Accomazzo, ESA's head of planetary missions, told reporters during a webcast press conference on Thursday.
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Initial analysis indicates that Schiaparelli began deviating from the flight plan when it jettisoned its parachute. At that point, the lander was supposed to fire up three hydrazine thrusters to help control its speed, but it appears the burn lasted just three or four seconds, far short of expectations, Accomazzo said.
"We do have all the data to find out what happened," he said.
Schiaparelli was heading toward a region of Mars known as Meridiani Planum, near where NASA's long-lived Opportunity is exploring.
The site is too far away for the rover to visit, but a pair of Mars orbiters, including the newly arrived Trace Gas Orbiter, will be listening for signals from the missing lander as they fly overhead.
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