ESA News
http://www.esa.int

21 June 2002

Stardust tests new ESA deep-space ground station in Australia

The spacecraft Stardust, which is on its way to meet the Comet Wild 2
in January 2004, last week helped ESA to carry out final testing of
the Agency's first deep-space ground station, situated just 140 km
north of Perth in New Norcia, Australia.

ESA's new 35-metre telemetry, tracking and command antenna has a
pointing accuracy of 0.01 degrees and will be a vital link in ESA's
Rosetta mission to the comet Wirtanen. This is one of the most
ambitious scientific missions ever to be launched and is scheduled
to take place early in 2003.

The 630-tonne antenna will be the main communications link between
Rosetta and Mission Control at ESA's European Space Operations
Centre (ESOC) in Germany. It will also be used to transmit and
receive data from other space missions sent to explore the Universe
beyond the Moon, such as ESA's Mars Express, also scheduled for
launch in 2003.

Stardust, which is a NASA Jet Propulsion Laboratory mission, was
selected for the tracking tests as it is on an interplanetary
trajectory currently more than 300 million km from the Earth. As
it passed over Australia on 8 June, at a maximum elevation of over
70 degrees, the New Norcia ground station successfully tracked the
spacecraft and received its signals.

The main objectives of the tests were to confirm the quality of
the pointing of the antenna and to see the downlink signal on a
spectrum analyser -- configured by a team from ESOC -- to catch
the low signals coming from the spacecraft. The characteristics
of the signal, together with precise orbital data, were kindly
provided by the Stardust team based at JPL. Their cooperation made
it possible to localise the spacecraft spectrum approximately half
an hour after the nominal downlink switch on.

Three days later additional tests were carried out to check the
pointing and to confirm the capability of the Intermediate
Frequency Modem System (IFMS) to track precisely the downlink
carrier for orbit determination purposes. All the objectives were
successfully achieved and the antenna has demonstrated that it is
working well. Everything is now ready for the official handover
to ESA in July 2002.