AMSAT-Phase 5-A


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AMSAT P5-A ground station successfully receives ESA's MARS-EXPRESS Probe

Since June 2nd 2003 the European probe MARS EXPRESS has been on it's way to the "red planet" scheduled to arrive on Christmas Day and to deploy the lander BEAGLE toward the Mars surface.

Joint preparations by the IUZ (Institut für Umwelt- und Zukunftsforschung / Institue for Environment and Future research) and the AMSAT-DL for this event have started months ago, because the 20 metre parabolic antenna is also deemed to be used as ground station for the AMSAT-DL for the future P5-A Mars Mission.


On Sunday, Nov. 16th, Germany saw a first event when a strong (40 dB Hz ~ 6 dB s/n at 2.4 kHz bandwidth) 8.4 GHz signal of the MARS EXPRESS - at that moment 102 million kilometer distant - was directly received at Bochum over a number of hours. The receive equipment was a horn, low noise downconverter to 1270 MHz and a Yaesu FT736R radio plus power meters . Although travelling through space with the speed of light it took about 6 minutes for the signals to be received on earth!

It was probably the first time that such a signal was received by amateur radio operators.

Bochum Random

The above picture shows the facilities in Bochum/Germany. The groundstation of ESA with a 35-m parabolic antenna is situated in New Norcia / near Perth, Australia.

Bochum Spiegel

For the project team (all radio amateurs), under the leadership of AMSAT-DL P5A Project Leader Prof. Dr. Karl Meinzer (DJ4ZC) and the director of the IUZ Thilo Elsner (DJ5YM), this is a decisive breakthrough for the AMSAT P5A Mars mission, due for launch in 2007.

This success was only possible after intensive renovation of the whole antenna installation. Dismantling, building and re-assembling much of the electrical and mechanical systems for command and control have been performed by the IUZ, (Bochum observatory) with support from companies "Eurotherm Deutschland" and "Mach4 Automatisierungstechnik". AMSAT-DL in particular was responsible in this cooperation for planning and implementing the control engineering for antenna pointing as well as for the RF techniques for receiving and converting of the signal. Thanks to these new systems, positioning of 1/100° was achieved for the 20 m parabolic antenna.

The IUZ staff involved were:

  • Guido Elsner/DL9DBP,
  • Werner Klein/DL5DAA,
  • Stefan Keidel/DB4QW,
  • Stefan Schröer/DH1DAC,
  • Ralf Höinghaus/DG5DAT
  • Thilo Elsner/DJ5YM.

The participating amateur radio personnel from AMSAT were:

  • Hartmut Päsler/DL1YDD - drive engineering and liaison with AMSAT-DL,
  • Freddy de Guchteneire/ON6UG - Feed system and RF-integration
  • James Miller/G3RUH - Tracking and antenna control software
  • Karl Meinzer/DJ4ZC - System design and AZ/EL-servo design
  • Michael Kuhne/DB6NT - 8.4 GHz-preamplifier and downconverter

The next highlight on the agenda will be the live observation of MARS EXPRESS when it arrives to the "red planet", which is expected for Christmas Day, December 25th  2003. Prior to that - on December 19th - a further test of the facility is scheduled to take place when the lander Beagle will be deployed from the probe.

With this successful test the general functional and operational readiness of the 20 metre parabolic antenna in Bochum to serve as AMSAT-DL command station for the P5A Mars Mission has been proven. It will then be used to navigate the P5-A Satellite safely towards Mars and to enter a Mars orbit. When AMSAT P5-A has left the Earth vicinity its signal will be too weak to enable reception for most of the amateur radio operators. Therefore it's intended to connect the Bochum ground station via the internet with the terrestrial amateur radio packet radio net to have telemetry data available on a broad and permanent basis. This will enable our "martians" (actively in the project participating people) as well as all amateur radio operators to have a permanent view on the advance the project is making. The command stations will then have the opportunity to enjoy the comfort of controlling the 20 metre parabolic antenna as well as the satellite via the internet

AMSAT P5-A is further expected to deploy a balloon from the "Mars Society Deutschland" onto Mars and P5-A will then be used as communication satellite to forward data signals from Mars to Earth. Some of the techniques required for this purpose will be tested on AMSAT- DL's new satellite AMSAT P3-E in the year 2005.

More sensational news from Bochum: The receiving system was improved with additional more than +4 dB from further testings on 22nd November. MARS-EXPRESS was received again with a stronger signal than before. In addition, the AMSAT/IUZ team succeeded in receiving the American probe MARS ODYSSEY on 8407 MHz. Since October 2001 MARS ODYSSEY has been orbiting the red planet, and the large doppler effect of approx. ± 100 kHz of the Mars orbit could easily be observed. This web page shows how MARS ODYSSEY sees the Earth from above.

Naturally this is one more good day, but it is still very early, and further optimisation will be performed on the system. However, we now know that we have a high grade and precise instrument available in Bochum of which we are all proud of. These are the best indications for success with the future AMSAT P5-A Mars mission.


AMSAT-DL Projektleiter P5-A Mars-Mission
Prof. Dr. Karl Meinzer
Ernst-Giller-Str. 20
D- 35039 Marburg
Tel. +49 6421 684112 Fax. 6421 2825665

Institut für Umwelt-und Zukunftsforschung
Direktor Thilo Elsner
Blankensteiner Straße 200a
D- 44797 Bochum
Tel. +49 0234 47711 Fax 234 461504

preliminary information, © AMSAT-DL