| | Postcards from Kourou
Postcard from Kourou - mosaic by ERS/SAR
1 February 2002
As Principal Integration and Test Engineer at Kourou,
Gilles Labruyère oversees the final preparations making Envisat
ready for the harsh environment of space. He's also
been keeping Europe-based colleagues up to date on
activities, with informal daily email 'postcards'
along with photographs and self-drawn cartoons, whose
subjects range from the state of the spacecraft itself
to his exotic surroundings on the coast of French
Guiana. Now you can follow his diary with us.
After ten years as part of ESA's Envisat project, it's
not surprising that Gilles feels close to
the spacecraft about to leave him behind.
"I think to myself: that's my satellite, that's my
baby!" Gilles said. "After so long working on it, I
feel like some part of myself has been transferred
inside it."
|  | Our Envisat diarist | |
A French national, Gilles graduated from the
prestigious Sup'Aéro engineering college in 1979, to
commence a 23-year space career. He joined ESA in
1987, and began work on Envisat in 1991.
"It was always a big, ambitious mission," Gilles said.
"At the time it was planned, scientists were
considering planet Earth for the first time as a
single inter-related system. Flying ten different
instruments together on Envisat, we'll finally be able
to observe the Earth that way too."
Over the years Gilles has witnessed the long odyssey
of Europe's largest and most complex satellite ever.
Envisat gradually took shape at contractor facilities
across the continent, before undergoing final
integration and extensive testing at ESTEC in the
Netherlands. Then it crossed the Atlantic to its
current resting place, the satellite preparation
complex at Kourou. Here it is undergoing final
preparations for its mission, its Ariane 5 rocket
waiting nearby. Envisat was built to investigate the
environment, but it must be kept safely cocooned from
the outside world.
| | Worked in a controlled environment | |
It is located inside a 'clean' room, accessible only
by airlocks. Inside this space, temperature, humidity
and dust are all controlled within strict limits. "You
could compare it to a surgical unit for a patient in
intensive care," Gilles said. "Except it isn't
bacteria we're worried about. "Temperature has to be
fixed, because the instruments have been very
precisely calibrated. Condensation from air humidity
could short out electronics, dry air may cause static
charging, while any dust the spacecraft collects could
spoil the reliability of the satellite."
| | The Ariane 5 launcher for Envisat | |
Human beings are another potential source of
contamination. "We give off all sorts of organic
compounds, in our breath, sweat or perfume," Gilles
said. "These can condense on delicate optics and
degrade them." Envisat engineers wear all-in-one coats
that cover from the tip of their shoes to the top of
their heads. They also put on masks and gloves if
working in really close proximity to the satellite,
while the most sensitive instruments have inert
nitrogen gas blown inside them as an extra precaution.
"The team rarely directly touch Envisat in a given
day," Gilles said. "I myself have only ever touched it
perhaps five times in total."
That doesn't mean Gilles isn't going to miss Envisat
when it's gone. He'll continue working on it right up
to launch. But for him and his team, the moment
Envisat leaves Earth will be a bittersweet moment.
"The time after the launch will be the difficult bit,"
Gilles said. "That's when responsibility for the
satellite hands over to the flight controllers at
ESOC. For us engineers at Kourou, it will feel like a
divorce."
| | Holland says "Tot ziens Envisat" | |
Envisat - the Story so far
Envisat first arrived in French Guiana on 16 May,
2001. It flew inside an Antonov 124, as two separate
modules: the service module and the payload module.
The two modules were then mated together after being
checked to confirm they had not been damaged by the
transport. Since then, large components like the
antenna of the radar and the solar array were fitted
onto the satellite. Since then, smaller components
were also integrated, such as the laser
retroreflector. Envisat began looking like a real
satellite.
| | Envisat Growth | |
Unfortunately the launch campaign had to be
interrupted in Mid-July because of the failure of the
Ariane 5 flight 142, with Artemis on board. With
Envisat due to fly the next Ariane 5, checks had to be
made. The campaign was resumed on 3 January 2002.
Arianespace had, by this time, an explanation for the
failure and validated corrective measures to ensure it
would not happen again.
Envisat was once again checked to ensure that it had
not been affected by the six-month storage period. The
preparation for the satellite for flight is, since
then, progressing according to schedule. The two main
activities so far were to prepare the mechanisms for
the storage and release of the solar array and the
antenna of the radar for the flight. Both have now
been completed. You can follow the preparations to
come by reading Gilles Labruyere's daily postcards.
"I try to send one postcard on each day we work. They
are always short and contain text only. They can be
about work, our life here or French Guiana in general.
I try to write these cards to be understandable by
all. But they also go to the Envisat team in the
Netherlands and acronyms and incomprehensible pieces
of jargon are sometimes the best manner to communicate
between us! Forgive me for this, please."
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