From: European Space Agency
Posted: Friday, November 25, 2011
After establishing contact with Russia's Phobos-Grunt Mars mission earlier this week, ESA's tracking station in Australia received no signal from the spacecraft last night. ESA engineers are investigating the cause in close collaboration with Russian mission controllers.
Despite listening intently during four scheduled communication passes during the night of 24-25 November, ESA's 15 m-diameter dish antenna at Perth, Australia, did not receive any signals . The slots for communication, timed to coincide when Phobos-Grunt was passing over in direct line-of-sight with the station, began at 20:12 GMT and ran until 04:04 GMT. Each lasted just 6-8 minutes, providing very limited windows for sending commands and receiving a response.
"Our Russian colleagues provided a full set of telecommands for us to send up," said Wolfgang Hell, ESA's Phobos-Grunt Service Manager, "and Perth station was set to use the same techniques and configurations that worked earlier. But we observed no downlink radio signal from the spacecraft."
ESA's contact with the Mars mission on the night of 22 November marked the first receipt of spacecraft data since contact was lost shortly after separation from the launch vehicle was confirmed on 8 November.
One piece of positive news: observations from the ground indicate that the orbit of Phobos-Grunt has become more stable.
"This could mean that the spacecraft's attitude, or orientation, is also now stable, which could help in regaining contact because we'd be able to predict where its two antennas are pointing," said Manfred Warhaut, ESA's Head of Mission Operations at the European Space Operations Centre, Darmstadt, Germany.
"The team here at ESOC will do their utmost to assist the Russians in investigating the situation."
The next scheduled communication slots for ESA's Perth station are set for the night of 28 November, when it will again be allocated to support Phobos-Grunt.
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