ESA News
http://www.esa.int

5 September 2008

Rosetta Steins fly-by confirmed

The Rosetta control room at ESA's European Space Operations Centre, ESOC,
received the first radio signal after closest approach to asteroid (2867)
Steins at 22:14 CEST [2014 UTC], confirming a smooth fly-by.
 
Closest approach took place at 20:58 CEST [1858 UTC] ground time, 20:38 CEST
[1838 UTC] spacecraft time, at a distance of 800 km. Rosetta's relative
speed with respect to Steins was 8.6 km/sec, or about 31 000 km/h. The exact
time of closest approach will be confirmed over the next few days after a
detailed analysis of telemetry data.

To optimise the science return from this historic encounter, a series of
critical operations were executed before closest approach, some of which
required the spacecraft flip over and change its orientation rapidly,
pushing it to its design limits.

After the flip, at 20:39 CEST [1839 UTC] (ground time), Rosetta switched to
the asteroid fly-by mode, during which its orientation was automatically
controlled by the on-board navigation cameras. The asteroid was tracked
continuously and kept it in the field of view of the imaging instruments.

At 20:48 CEST [1848 UTC] (ground time), while still in asteroid fly-by mode,
Rosetta's high gain antenna was turned away from Earth and the science
observations were carried out. Radio contact established again at 22:14 CEST
[2014 UTC] and the first bit of telemetry was received through NASA's
Goldstone antenna.

Science data download will start tomorrow morning, 6 September at about
02:00 CEST [0000 UTC] and continue through the night. Images and the
preliminary results from the fly-by will be presented tomorrow at a press
conference which be held at ESOC starting at 12:00 CEST [1000 UTC]. The
press conference will be streamed on the web at www.esa.int/rosetta .

[NOTE: Images and weblinks supporting this release are available at
http://www.esa.int/esaCP/SEMUOWO4KKF_index_1.html ]
--- SBBSecho 2.12-Win32