Aihnss.2628 net.space utzoo!decvax!ucbvax!ihnss!karn Sat Mar 27 19:16:00 1982 Shuttle Visibility; Communications query After the launch of STS-3, I derived an approximate set of orbital elements and ran them through a program I have that checks for visibility for my location. It has been making 4 or so passes daily, all during daylight, past my location (Chicago). Unfortunately, none of the passes occur during twilight, which is the only time the shuttle can be optically sighted. This checks with an AP news story I saw which has the shuttle being visible only twice from the USA during the STS-3 mission: once from Honolulu and once from New Orleans. The problem is the time of launch (middle morning) and the low orbital inclination (38 degrees). The orbital inclination is kept low to maximize the payload capacity, and the time of launch is fixed by daylight requirements at the launch and abort landing sites. I'm sure that when Vandenburg starts up, there should be some opportunities for sighting the shuttles, since they'll be launched into polar orbits from there. On another subject: does anybody have a DETAILED description of the communications gear aboard the shuttle? I have a list of S-band and UHF frequencies, but I don't know the modulation schemes used and which channels carry voice, data, TV, etc. Phil Karn