Aihnss.184 net.columbia utzoo!decvax!ucbvax!mhtsa!ihnss!karn Thu Nov 12 15:48:54 1981 Shuttle orbital parameters I have derived a set of orbital elements for the Columbia based on the sketchy information I previously put on the net, plus the actual launch time, which was 15:10:02 UTC by my watch. Epoch time: Thu Nov 12 00:11:42 1981 UTC (actually a phony time, since the launch hadn't occurred yet) 81316.00812500 Inclination: 38.0000 deg (from AW&ST) RA of node: 159.7950 deg (from actual launch time, plus given equator crossing data) Eccentricity: 0.0000000 (assuming perfect circular orbit) Arg of perigee: 0.0000 deg (meaningless for circular orbit) Mean anomaly: 0.0000 deg (") Mean motion: 16.12541993 rev/day (based on given period of 89.3 min) Decay rate: 0 rev/day/day (hopefully insignificant for short mission) Semi major axis: 6618.02 km Period: 89.30 min (from AW&ST) Apogee: 239.88 km (calculated) Perigee: 239.88 km (") While the Columbia is making several passes that are above my horizon (Chicago), they are all during daylight which rules out optical sighting. It appears that the orbit is oriented such that Columbia is crossing the equator going north (the ascending node) at about the morning terminator, and crossing the equator going south at about the evening terminator. Except during midday, the shuttle passes our longitude too far south to be above the horizon here (or in NJ). Observers farther south (e.g., Texas, Fla) should be able to see it. Anybody down there wanna give me your coordinates? I could try running them through my program. Phil ----------------------------------------------------------------- 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.