Posted: September 04, 2008
The Rosetta control room is buzzing with anticipation as ESA’s comet-chasing spacecraft makes its final preparations for a fly-by of asteroid (2867) Steins on the evening of 5 September.
Artist impression of Rosetta as it swoops towards asteroid (2867) Steins. Closest approach is scheduled for 20:58 Central European Summer Time. Image: ESA/C. Carreau.
Just prior to closest approach the spacecraft will be flipped, and switched into a specially designed asteroid fly-by mode, providing optimal observation and tracking conditions. Science observations will be at their best thanks to good illumination conditions from the Sun. At the time of closest approach Rosetta will skim past the asteroid at a distance of 800 kilometres and a speed of 8.6 kilometres per second relative to Steins. At this time, communications between the Earth and the satellite will take 20 minutes each way.
Rosetta's stop-off at Steins is extremely important, since asteroids represent samples of Solar System material at different stages of evolution, allowing planetary scientists to put together the jigsaw puzzle of Solar System evolution and finding the Earth's place amongst the chaos.
After the call-in on Steins, Rosetta will make one more fly-by of the Earth in November 2009 before being placed back into deep space hibernation for three years prior to reaching its final destination of Comet 67P/Churymov-Gerasimenko in 2014.
A time line of fly-by events are scheduled as follows (all times in CEST, Central European Summer Time):
A Rosetta blog and expanded timeline of events is available at: http://webservices.esa.int/blog/blog/5/ and images from the fly-by will be streamed on the ESA website.
Aug 05 Rosetta sets Steins in sites... read more
Jul 07 Rosetta woken from hibernation... read more