New amateur satellite transponder
project announced

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

Professor Sir Martin Sweeting G3YJO

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 by 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.

A launch from Plestek

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 G0MRF and Jason Flynn G7OLD with Graham Shirville G3VZV assisting.

Click here for larger image

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 emphasised that AMSAT-UK is delighted to have been entrusted with such an important task and that development team will have the organisation's full support.

Membership of AMSAT-UK is just £15 a year and all members receive the publication Oscar News.

For further information contact the AMSAT-UK secretary

Jim Heck G3WGM
Tel: 01258 453959
E-mail: g3wgm@amsat.org
Website: www.uk.amsat.org

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