[extropy-chat] The Rosetta launch is so far successful

[Amara Graps]

9:30 2 March, Central Europe time
The Rosetta launch from ESA's Kourou station is so far successful.
The initial lift off was incredibly smooth and fast. (So few
'flames'! Just straight up and fast and then away! Like a dream.)
The first stage released, then the protective fairing separated.
 From an initial speed of 2 km/s, Rosetta was accelerated to 8 km/s,
and now it is in a coasting (ballistic) phase, in earth orbit, for
about 30 minutes more (2 hours total in the coasting phase). At about
10am, Europe time, the second stage must kick in and accelerate
Rosetta to at least Earth's escape velocity at that altitude (about
11 km/s or perhaps slightly less). Then off to the comet, with the
following detour to pick up the necessary energy from the
gravitational fields of Earth and Mars until 2014.


First Earth fly-by: November 2005
Mars fly-by: February 2007
Second Earth fly-by: November 2007
Third Earth fly-by: November 2009
(It will travel through the asteroid belt twice)

Deep-space hibernation: May 2011 - January 2014

Comet approach: January-May 2014
Comet mapping / Characterization: August 2014
Landing on the comet: November 2014
Escorting comet around the Sun: November 2014 to December 2015

When it meets Comet 67P/Churyumov-Gerasimenko, it will be near the
comet's aphelion distance from the Sun ~5.2 AU (this is orbital
position of Jupiter). The reason for meeting it at that part of its
orbit is that the comet's orbit is highly eccentric (0.6), and since
Rosetta has to match speeds, it needs to do it at the part of the
orbit when the comet is traveling slowest (remember Kepler's Second
Law). I think the comet is traveling roughly 15 km/s at that time.

Now holding the breathe for the last part of the launch.

Amara

(about Comet 67P/Churyumov-Gerasimenko)
http://www.esa.int/export/SPECIALS/Rosetta/ESAGJF7708D_0.html
-- 

Amara Graps, PhD
Istituto di Fisica dello Spazio Interplanetario (IFSI)
Istituto Nazionale di Astrofisica (INAF),
Adjunct Assistant Professor Astronomy, AUR,
Roma, ITALIA     Amara.Graps at ifsi.rm.cnr.it