Aihnss.154 net.columbia utzoo!decvax!ucbvax!ihnss!karn Wed Oct 7 06:48:44 1981 UoSAT/Oscar-9 Operating After some initial difficulties in getting modulation onto the 2-meter beacon, the command station in the UK has succeeded in getting Uosat-Oscar-9 to transmit 300 baud ASCII telemetry. I just heard a pass at my station in which the spacecraft did seem to be sending 300 baud ASCII, although I did not have a a modem connected to the receiver to decode it. The tones are 1200/2400 Hz, which can be received with a Bell 202 (NOT 103) modem. On the first orbit after launch yesterday, passing over the UK, command stations were able to turn the 2-meter beacon on and off, but were unable to get any telemetry modulation. Without this data, there was concern over the attitude of the spacecraft, in that it seemed likely that the sun was shining down on its top. Due to the thermal design of the spacecraft, this causes lower-than-nominal temperatures. Without positive control shortly after launch, it was not possible to attempt to command the spacecraft into a bottom-toward-earth attitude until the next series of passes over ground command stations in the UK. For those of you who asked, some Oscar-9 data follows. You need an amateur 2-meter receiver and, ideally, a tracking program using classical orbital elements as input. 2-meter beacon: 145.825 Mhz, 350 milliwatts, left hand circular polarization. This is strong enough to be recieved with a hand-held transceiver! 70-cm beacon: 435.025 Mhz, 650 milliwatts, LHCP. Has not been commanded on yet, to my knowledge. Orbit elements: Epoch time: Tue Oct 6 07:26:14 1981 CDT 81279.51821950 Element set: 127 Inclination: 97.4687 deg RA of node: 242.0175 deg Eccentricity: 0.0003192 Arg of perigee: 317.0446 deg Mean anomaly: 43.0536 deg Mean motion: 15.09377490 rev/day Decay rate: 0 rev/day/day Epoch rev: 1 Semi major axis: 6916.24 km Period: 95.40 min Apogee: 550.07 km Perigee: 545.65 km This is a sun-synchronous polar orbit with 3AM/3PM descending and ascending nodes, respectively. Passes are short: about 12 minutes, maximum, for an overhead pass. If you don't have a tracking program, then just put your receiver on 145.825 Mhz FM and squelch it. Connect it to an omnidirectional antenna and listen. Passes for today, October 7, for my station (near Chicago, IL) are 1:50-1:56pm CDT, to the east; 3:21-3:31pm CDT, almost overhead; and 4:57-5:03pm CDT, to the west. Listen during these times and you should hear something. Doppler is plus and minus several kilohertz. Phil Karn, KA9Q ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.