gamorris@lescsse.uucp (Gary A. Morris) (12/05/90)
Houston 4 Dec 90 - 17:00 UTC There have been some success and some problems with SAREX (Shuttle Amateur Radio EXperiment) on STS-35. On the first inflight test of the bridge system (2 Dec 90 0316 UTC) we were unable to make any contact with Ron. We have confirmed that he had a weak voice contact sometime before the bridge test time with a station in Florida. On the second bridge schedule, which was to be a realtime connection between Ron, WA4SIR, and a classroom of children on school, we were unable to establish two way contact with Ron during the pass over Sao Paulo, Brazil. We did hear him for about 10 seconds of the 10 minute pass but couldn't establish conact. The most likely cause of the weak signal is the orbiter attitude during the contact. The SAREX antenna is in the right side window on the flight deck and at the time of the Sao Paulo pass the orbiter was tail down. The orbiter attitude is determined by needs of the primary payload. A second bridge system test was scheduled for a pass over Australia but Ron was unavailable at the time of the pass (4 Dec 90 0205 UTC) and no contact was made. Ron was also asked to attempt direct contact with W5RRR on orbit 30. This contact was successful, Roy Neil talk to Ron for about 7 minutes as he passed south of Houston. Ron said that he had heard us full quieting on the pass over Sao Paulo but we couldn't hear him. The orbiter attitude was good for this pass which confirms that the orbiter attitude is important. This pass had only a 6 degree maximum elevation in Houston, we believe elevation and range are not significant factors in making a contact with the shuttle. The amateur radio voice contact with the Mir space station is uncertain at this time. The first close conjunction (53 km) with Mir was to occur today (4 Dec 90) but the Mir crew is unavailable for radio contact due to the docking with the Soyuz and arrival of the new crew. The next close conjunction (57 km) is about 4 hours after the SAREX stow time on Dec 11. This contact can only take place if mission controllers approve delaying the stow of SAREX and the mission is extended the extra day. Vance Brand has been brushing up his Russian language skills which he learned for the Apollo-Soyuz mission. The packet robot has been operating on schedule (included below). As of this morning (4 Dec 90 1600 UTC) over 400 contacts have been made with amateur radio operators using packet. If you experience weak signals on the downlink, it is likely that the orbiter is in an unfavorable attitude for you. It can improve or degrade as the orbiter passes depending on which side of the orbiter is facing you. The attitude is constantly being changed to support the telescopes, so if you experience weak signals, try again on later orbits. Packet Robot Operating Schedule 03 Dec 90 03:19 - 16:19 UTC 04 Dec 90 03:19 - 15:44 UTC 05 Dec 90 03:19 - 15:34 UTC 06 Dec 90 03:19 - 15:49 UTC 07 Dec 90 03:19 - 15:34 UTC 08 Dec 90 03:19 - 15:44 UTC 09 Dec 90 03:19 - 15:34 UTC 10 Dec 90 03:18 - 15:04 UTC 11 Dec 90 02:49 - 14:34 UTC (only if mission is extended one extra day) The element set (below) is from JSC based on orbiter state vector, the NORAD data is different by about 7 seconds on equator crossing times. The JSC 2 line set has 00035 for the object number, whereas the NORAD set has 20980. If you had set JSC-012, there is really no need to update to this one, the difference is small (about 10 seconds). Keplerian Element Set STS-35 1 00035U 90337.58101852 .00031000 00000-0 22174-3 0 130 2 00035 28.4623 355.6417 0008957 294.4128 292.2542 15.72222895 229 Satellite: STS-35 Epoch time: 90337.58101852 (03 Dec 90 13:56:40.000 UTC) Element set: JSC-013 Inclination: 28.4623 deg Space Shuttle Flight STS-35 RA of node: 355.6417 deg Keplerian Elements Eccentricity: .0008957 from NASA Tracking Ephemeris Arg of perigee: 294.4128 deg Mean anomaly: 292.2542 deg W5RRR Mean motion: 15.72222896 rev/day NASA Johnson Space Center Decay rate: 3.10E-04 rev/day^2 Epoch rev: 22 -- Gary Morris Internet: lobster!lescsse!gamorris@menudo.uh.edu Lockheed (LESC), A22 UUCP: lobster!lescsse!gamorris Space Station Freedom NASAmail: gmorris/jsc/nasa Houston, Texas Internet: gmorris@nasamail.nasa.gov