ESA Rosetta Spacecraft now in orbit around a comet - eventually to land on it!

[Peter Lemkin]

SUMMARY

Rosetta is a cornerstone mission to chase, go into orbit around, and land on a comet. It will study the Jupiter-family comet 67P/Churyumov-Gerasimenko with a combination of remote sensing and in situ measurements. The spacecraft will orbit the comet and release the Philae lander, which carries a suite of instruments for imaging and sampling the comet nucleus. The mission will track the comet through perihelion, examining its behaviour before, during and after.[TABLE="width: 295, align: right"]
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[TD]Rosetta and Philae at the comet.
Credit: ESA- C. Carreau/ATG medialab
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The mission was first considered in the late 1970s and developed from a sample-return plan to the plan for a lander. It was approved in November 1993 by ESA's Science Programme Committee. The original mission target had been comet 46P/Wirtanen, but this was changed to 67P/Churyumov-Gerasimenko when it was clear that the launch would take place in 2004.
The spacecraft was launched from Kourou aboard an Ariane 5G+ on 2 March 2004. It required four gravity assists for its journey, one by Mars and three by Earth. Rosetta had already flown by the asteroids 2867 Steins (in 2008) and 21 Lutetia (in 2010), before entering deep space hibernation in June 2011.
Rosetta's main goals will be reached in 2014. Following a planned exit from hibernation on 20 January, the spacecraft's instruments were checked as it continued on its journey to 67P/Churyumov-Gerasimenko. The spacecraft arrives at the comet in August 2014, and deploys the lander in November 2014.
Here are the key dates of the Rosetta mission:

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[TD="bgcolor: #cccccc, align: center"]Event[/TD]
[TD="bgcolor: #cccccc, align: center"]Nominal date[/TD]
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[TD="bgcolor: #cccccc, align: left"]Launch[/TD]
[TD="bgcolor: #cccccc, align: right"]2 March 2004[/TD]
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[TD="bgcolor: #cccccc, align: left"]First Earth gravity assist[/TD]
[TD="bgcolor: #cccccc, align: right"]4 March 2005[/TD]
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[TD="bgcolor: #cccccc, align: left"]Mars gravity assist[/TD]
[TD="bgcolor: #cccccc, align: right"]25 February 2007[/TD]
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[TD="bgcolor: #cccccc, align: left"]Second Earth gravity assist[/TD]
[TD="bgcolor: #cccccc, align: right"]13 November 2007[/TD]
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[TD="bgcolor: #cccccc, align: left"]Asteroid Steins flyby[/TD]
[TD="bgcolor: #cccccc, align: right"]5 September 2008[/TD]
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[TD="bgcolor: #cccccc, align: left"]Third Earth gravity assist[/TD]
[TD="bgcolor: #cccccc, align: right"]13 November 2009[/TD]
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[TD="bgcolor: #cccccc, align: left"]Asteroid Lutetia flyby[/TD]
[TD="bgcolor: #cccccc, align: right"]10 July 2010[/TD]
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[TD="bgcolor: #cccccc, align: left"]Enter deep space hibernation[/TD]
[TD="bgcolor: #cccccc, align: right"]8 June 2011[/TD]
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[TD="bgcolor: #cccccc, align: left"]Exit deep space hibernation[/TD]
[TD="bgcolor: #cccccc, align: right"]20 January 2014[/TD]
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[TD="bgcolor: #cccccc, align: left"]Rendezvous manoeuvres begin[/TD]
[TD="bgcolor: #cccccc, align: right"]May 2014[/TD]
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[TD="bgcolor: #cccccc, align: left"]Arrive at comet[/TD]
[TD="bgcolor: #cccccc, align: right"] 6 August 2014[/TD]
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[TD="bgcolor: #cccccc, align: left"]Start global mapping[/TD]
[TD="bgcolor: #cccccc, align: right"]August 2014[/TD]
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[TD="bgcolor: #cccccc, align: left"]Lander delivery[/TD]
[TD="bgcolor: #cccccc, align: right"]November 2014[/TD]
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[TD="bgcolor: #cccccc, align: left"]Perihelion passage[/TD]
[TD="bgcolor: #cccccc, align: right"]13 August 2015[/TD]
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[TD="bgcolor: #cccccc, align: left"]End of mission[/TD]
[TD="bgcolor: #cccccc, align: right"]31 December 2015

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