Representatives of the Rosetta science instrument teams came together
from all over Europe and the United States this week for the 7th meeting
of the Rosetta Science Working Team.

The purpose of the gathering at the premises of Alenia Spazio in Turin was
to familiarise everyone with the latest status of the programme. However,
the primary consideration for everyone was the limited time remaining to
complete the spacecraft Assembly, Test and Verification programme —
766 days to launch … and counting.

Members of the ESA project team for Rosetta explained to the 80-strong
audience that the Electrical Qualification Model (EQM) test programme on
the Orbiter and Lander is now half completed, although considerable work
remains to be done.

All of the Orbiter’s EQM instruments have been delivered and are currently
undergoing functional testing. This phase of the intensive EQM programme
is scheduled for completion by the end of January 2001, after which the
instrument compatibility tests will begin.

“Progress is being made, but not quite as fast as we originally hoped,” said
ESA Project Manager John Ellwood. “However, engineers at Alenia are
working double shifts and we are confident that we will be able to catch
up with our tight schedule.”

Meanwhile, all of the experiments on the Orbiter have passed their Final
Design Reviews after several months of discussions about the results of
tests on prototype instruments that have been carried out at the various
institutes. This is an important step towards the Mission Critical Design
Review in April 2001.

The meeting was also informed that the Assembly, Integration and
Verification programme for the Rosetta Orbiter Flight Model will take place
in parallel to the EQM tests. The first step will be the delivery of the Flight
Model structure from Finland to Italy in mid-January, followed immediately
by the delivery of key subsystems such as the harness and the Reaction
Control System.

The scientists were able to see for themselves the current state of play
in the EQM programme during a visit to the giant clean room at Alenia,
where they could inspect at close quarters the Rosetta Orbiter and Lander
EQMs (as well as the Flight Model of ESA’s Integral gamma ray observatory
which is scheduled for launch in 2002).

However, the main message for the gathered assembly was pronounced
early on the first day by John Ellwood.

“No major technological risks are outstanding, but we must all continue to
make every effort to meet our deadlines,” he said.

“We are ‘Go’ for launch on 12 January 2003 — but Comet Wirtanen will not


* More about Rosetta


[Image 1:]
The faint, moving image of the nucleus of Comet Wirtanen (in the circles),
as observed by the 8.2-m VLT KUEYEN telescope (formerly UT2) and the
VLT Test Camera on 17 May 1999, during the commissioning phase.
Photograph courtesy ESO.

[Image 2:]
Rosetta Orbiter EQM at Alenia Spazio in Turin, Italy, 11 October 2000.

[image 3:]

Rosetta rises to meet the challenge. A three colour image of Comet
Wirtanen, taken from observations on Pik Tersko, which shows the three
cometary components — dust, neutral gas and ions. Using different filters
on the telescope, the cometary water (H2O) ions appear red, the dust is
green and neutral CN gas is blue.

This shows Wirtanen’s ion tail (here H2O+) for the first time. It appears as
a straight, red diffuse band to the left side (anti-sunward direction). The
blue sphere is the very extended neutral CN coma. In contrast to this, the
dust is much more concentrated and dominates the near nucleus region,
here seen as a yellowish green colour. This image illustrates that
46P/Wirtanen is dust poor and about 2-3 times less dusty than Comet

Photo Max-Planck-Institut fur Aeronomie, courtesy T. Credner, J. Jockers,