Waspie_Dwarf Posted April 2, 2015 #1 Share Posted April 2, 2015 Rosetta status report: close flyby navigation issues During its most recent close flyby last Saturday, where Rosetta flew within 14 km of the surface of the comet, the spacecraft experienced significant difficulties in navigation. This resulted in its high gain antenna starting to drift away from pointing at the Earth, impacting communications, and was subsequently followed by a ‘safe mode’ event. The spacecraft has now been successfully recovered, but it will take a little longer to resume normal scientific operations. Read more... 1 Link to comment Share on other sites More sharing options...
Waspie_Dwarf Posted April 15, 2015 Author #2 Share Posted April 15, 2015 Rosetta keeps its distance from awakening comet Mission controllers are rethinking a series of close-up comet flybys planned for Europe’s Rosetta spacecraft after a haze of dust around the comet’s central nucleus led to navigation errors during a close encounter in late March.Rosetta’s computer put the spacecraft into safe mode in the aftermath of a March 28 flyby of comet 67P/Churyumov-Gerasimenko. Star trackers aboard the solar-powered probe were unable to lock on to guide stars, confusing the craft’s navigation system and causing Rosetta’s communications antenna to drift off alignment with Earth. Read more... Link to comment Share on other sites More sharing options...
Merc14 Posted April 15, 2015 #3 Share Posted April 15, 2015 (edited) Couldn't they just turn of the star tracker as they fly through the corona, sort of a dead head cruise by and then back on line at a predetermined time that is clear of the dust? Store the data on board until realigned and then transmit. Priority, of course, is to watch the entire event unfold as 67P gets closer to the sun. Edited April 15, 2015 by Merc14 Link to comment Share on other sites More sharing options...
Waspie_Dwarf Posted April 15, 2015 Author #4 Share Posted April 15, 2015 Couldn't they just turn of the star tracker as they fly through the corona, sort of a dead head cruise by and then back on line at a predetermined time that is clear of the dust? Store the data on board until realigned and then transmit. Priority, of course, is to watch the entire event unfold as 67P gets closer to the sun. Without the star trackers the craft won't have a clue which way it is pointing. Not only will it not know where to point the cameras it also won't know where Earth is to transmit the results to. A single piece of dust hitting the craft could knock it off course and the vehicle would have n idea ho to realign itself. Even if, by a miracle, it did manage to get useful science done if the star tracks failed to switch back on you could kiss Rosetta good-bye, it would be game over for the mission. 1 Link to comment Share on other sites More sharing options...
Merc14 Posted April 16, 2015 #5 Share Posted April 16, 2015 Without the star trackers the craft won't have a clue which way it is pointing. Not only will it not know where to point the cameras it also won't know where Earth is to transmit the results to. A single piece of dust hitting the craft could knock it off course and the vehicle would have n idea ho to realign itself. Even if, by a miracle, it did manage to get useful science done if the star tracks failed to switch back on you could kiss Rosetta good-bye, it would be game over for the mission. OK thanks. Obviously long duration is the main objective so definitely better safe than sorry. Link to comment Share on other sites More sharing options...
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