Rosetta is an ESA (European Space Agency) spacecraft, launched towards
a comet in March 2, 2004. To be able to catch up with the comet,
Rosetta has to take a long route through the planetary system,
including three flybys of Earth and one of March. At the Swedish
Institute of Space Physics in Uppsala, we have built an instrument
called LAP (Langmuir probe)
to study the ionized gas (plasma) close to the comet. However, this
instrument and its companion instruments in the Rosetta Plasma
Consortium, RPC, can be used also for exploring space around Mars and
Earth during the flybys. The Mars flyby is highly interesting, as very
few spacecraft with reasonable plasma instrumentation have ever visited
Mars. As an example, none of the spacecraft now at Mars have anything
to match the RPC instrumentation.
While the Mars flyby is of obvious scientific interest, the Earth
flybys may at first sight seem to be less fun. Around Earth, there are
of course a lot of measurements made by instruments on spacecraft
specifically constructed to observe the near-Earth space environment.
However, there are several reasons for doing plasma science with RPC
during the flybys: (1) calibration of instruments in a reasonably known
environment; (2) rehearsal for the Mars flyby -- do the operational
modes we want to use really give the desired results, or should we
change them slightly?; and (3) a real scientific interest also at
Earth: during the flybys, Rosetta will be an extra measurment point
around Earth, and multispacecraft studies are vital for understanding
In order to get the most out of the Earth and Mars flybys, careful
planning is needed, including modelling of the environment. This is the
topic of the present work.
Magnus developed Matlab routines for reading, manipulating and
visualizing orbit and attitude information, and
used it to prepare for the first Rosetta Earth flyby (March 4, 2005).
He modelled the expected radiation dose, thereby building the basis for
our decision to stay on during the flyby. He compared some results to
during the flyby, and provided overview of the remaining Earth and Mars
flybys. The project was completed in June 2005.
Anders Eriksson, Anders.Eriksson@irfu.se
Rosetta interplanetary trajectory.
(1) Launch, 2 March 2004.
(2) First Earth swingby, 3 March 2005.
(3) Mars swingby, 26 February 2007
(4) Second Earth swingby, 14 November 2007
(5) Asteroid flyby
(6) Third Earth flyby, 11 November 2009
(7) Asteroid flyby
(8) Arriving at the comet in 2014
last modified onMonday, 29-Aug-2005 14:25:59 CEST