[HamSat] New amateur satellite transponder project announced

[Timothy Pickett]

The Chairman of AMSAT-UK, Professor Sir Martin Sweeting G3YJO
announced a new amateur transponder project to be launched as part of the
ESA SSETI Express satellite.

Speaking at the opening of the 2004 AMSAT-UK Colloquium at the University of
Surrey in Guildford, he expressed his delight that AMSAT-UK has been able to
work with the European Space Agency to provide, at very short notice, an S
band (2.4GHz) transmitter.

The SSETI Express project is believed to be the first ever pan-European
student satellite with over 100 students from more than nine different
countries working on it. The project is being coordinated and managed buy
the Education Office of ESA.

It is intended that this transmitter will be available for use as the
downlink of a single channel FM U/S transponder. The 437MHz receiver is also
being provided to ESA by another radio amateur - Holger Eckart DF2FQ.

These frequencies will enable the many amateurs who already have Oscar 40
equipment to use it in an exciting new way.

After integration of the spacecraft, which is due to start at the ESTEC
laboratories in the Netherlands next month (August), SSETI Express is
intended to be launched into a sun synchronous 680km orbit from Plestek in
Russia in April 2005.

The satellite is in the 80kg class and is being designed and constructed by
a number of European University teams which include students and teachers.
The onboard experiments include attitude control, a camera and a cold gas
propulsion unit.

It is intended that the 2.4GHz downlink transmitter will transmit satellite
telemetry and data at 38k4 data rate before being switched over to voice
transponder operation after the onboard experiments have been completed.

ESA will shortly be announcing a worldwide competition for radio amateurs
who download the data from the satellite and forward it to a website which
is under construction. There will be a valuable award for the amateur who
provides the largest amount of verified data over the first few weeks/months
of operation.

The 2.4GHz downlink exciter, the switched mode power supply and control
interfaces are being developed by an AMSAT-UK team comprising of Sam Jewell
G4DDK, David Bowman G0MRFand Jason Flynn G7OLD with Graham Shirville G3VZV
assisting.

The 3 watt 2.4GHz power amplifier is completed and has been provided by
Charles Suckling G3WDG and this unit is already space qualified as it is
identical to the one flying in the recently launched Oscar 51 spacecraft.

The S band antennas are three flat plate patches that have been developed
and produced by the Wroclaw University of Technology in Poland.

Professor Sir Martin Sweeting emphasized that AMSAT-UK is delighted to have
been entrusted with such an important task and that development team will
have the organization's full support.

Those interested in finding out more about Amateur Satellites may like to
know that AMSAT-UK produce an excellent newsletter called Oscar News which
is sent to all members. For further information contact the AMSAT-UK
secretary Jim Heck, G3WGM

Tel: +44 (0)1258 453959
E-mail: g3wgm at amsat.org
Website: www.uk.amsat.org