FOR IMMEDIATE RELEASE Number 94-02 March 22, 1994 AMSAT PHASE 3-D INTERNATIONAL SATELLITE BUILDERS MEET IN MARBURG--PROPELLANT TANKS DELIVERED During the week of February 10-16, 1994, Dr. Karl Meinzer, DJ4ZC, AMSAT-DL President and Project Leader for the International AMSAT Phase 3-D satellite, and Werner Haas, DJ5KQ, Vice-President of AMSAT-DL hosted a working meeting in Marburg, Germany to discuss recent progress on the project. Agenda items centered primarily around the spacecraft's electronic systems including the on-board computer (IHU) and RUDAK systems, as well as the progress now being made by team members on the spacecraft's other electronic modules. Also during the meeting, the team took delivery of P3-D's main propellant tanks. The tanks were manufactured in Russia under contract from AMSAT-DL and in accordance with AMSAT specifications. Seven tanks were delivered, although one had been subjected to a destructive pressure test by its Russian manufacturer. Not only have all the propellant tank specifications been fully achieved, but they've actually been significantly surpassed. Each tank can accommodate almost 50 liters of propellant. Favorable conditions for the purchase and delivery of these tanks was arranged through the efforts of AMSAT-UA (Russia). Following a brief inspection, the tanks were immediately shipped to Orlando, Florida, where integration of the satellite is now slated to begin this summer. Dick Jansson, WD4FAB, AMSAT-NA Vice-President for Engineering, also attended the meeting, principally to discuss various aspects of the satellite's structure with Dr. Meinzer and Konrad Mueller, DG7FDQ. He reported on the good progress of the flight model structure's construction, currently underway at Weber State University in Utah. Also in attendance were Lyle Johnson, WA7GXD, Peter Guelzow, DB2OS, and Gerhard Metz, DG2CV. Lyle is known through his work with the Tucson Amateur Packet Radio (TAPR) group (which he co-founded) as well as for his work on the MICROSATs and on the P3-D GPS project. After much discussion, the team decided to again employ a cable wiring harness arrangement for Phase 3-D, similar to that used on AO-10 and AO- 13, rather than an AART-based LAN design. However, the team decided to also fly a CAN bus and DB2OS's experimental LAN controller as part of the spacecraft's digital (RUDAK) transponder. In a related decision, the group concluded that the AO-10/AO-13 1802-based Internal Housekeeping Unit (IHU) computer design would still be adequate for P3-D with some minor modifications. Lyle Johnson announced his willingness to redesign the IHU and to construct a flight unit. His offer was gratefully accepted. Other meeting items centered on P3-D's RUDAK work now being done by Peter Guelzow, Gerhard Metz, and Dr. Stefan Eckart, DL2MDL. This team has now decided to build two RUDAKs. The first will be a user-oriented digital communications module constructed by Lyle Johnson, in close cooperation with Peter Guelzow. This RUDAK, which has yet to be formally named, will be the one most P3-D satellite users will operate. A second, more experimental RUDAK (called RUDAK-E), will be built in Germany. It will promote experiments with advanced high speed modems, Digital Signal Processing (DSP) techniques, and new communications protocols. In a host of other issues, Daniel Orban, ON4AOD, discussed details of the 24 GHz transmitter. Konrad Hupfer, DJ1EE, reported his progress in building the 250 watt U-Band (70 cm) final amplifier. Werner Haas displayed his first flight hardware consisting of two command receivers, a digital section, and the 70 cm exciter that will drive Konrad's 70 cm final amplifier. Freddy De Guchteneire, ON6UG, reported his progress on the construction of dual V-Band and U-Band receiver "front-ends". Dr. Matjaz Vidmar, S51MV, reported he has now begun construction of the HF-Band, C-Band and S-Band receivers. He expects to deliver working prototypes in May. While much work still remains to be done, Dr. Meinzer expressed his approval and sincere thanks to all participants for their superb work and close cooperation on this vitally important AMSAT international project. A complete text of this meeting's minutes has been prepared by Peter Guelzow, and has since been translated by Don Moe, DJ0HC/KE6MN. The text will be made available to the various international AMSAT Journals for possible inclusion in their upcoming editions [Peter Guelzow, DB2OS, Don Moe, DJ0HC/KE6MN, Lyle Johnson, WA7GXD, and Keith Baker, KB1SF, contributed to this News Release.] For more information contact: Keith C. Baker, KB1SF 1324 Fairgrounds Road Xenia, Ohio 45385-9514 USA "kb1sf@amsat.org"