Other than the launch itself, scheduled for early 2003 Dec 02 UTC, the only suspense relates to the number of NOSS satellites to be deployed. Though the 2001 launch deployed only two NOSS, I have always believed that three were on board, and that one of them failed to separate from the Centaur stage. The eleven previous NOSS successfully launched between 1971 and 1996, all consisted of three satellites orbiting in a close triangular formation. They are believed to detect radio transmissions from ships at sea, and analyze the signals to triangulate on the precise location of the transmitter. This enables the U.S. Government to locate and track foreign vessels of interest. Although I have no expert knowledge of the operation of the NOSS, it is my belief that three satellites are required to most accurately determine the position of transmitters, so the unprecedented deployment of only two NOSS after the 2001 launch was a great surprise. Hobbyists closely tracked both NOSS as they manoeuvred into their final orbits. During the first couple of months after launch, both made several small manoeuvres that varied the distance between them. For a short time, they were 1500 km apart, then gradually moved to within the normal 60 km distance. I speculate that the changes in distance may have been experiments to determine the optimal spacing of the two spacecraft, to salvage as much ship-locating accuracy as possible, after the loss of the third spacecraft. US News & World Report published an article on 2003 Aug 11 (abstract below), reporting problems with the NOSS and the KeyHole satellite launched in 2001: http://www.usnews.com/usnews/issue/archive/030811/20030811041138_brief.php From my copy of the article, the quotes relevant to NOSS: "Not long after launch on Sept. 8, 2001, the satellite initially failed to operate once in orbit. "We had a problem shortly after launch," a company spokesman told U.S. News." "In fact, an electronic circuit on the satellite had failed to work. Says a Lockheed Martin spokesman: "We fixed the problem. There was no impact to mission ops." Still, he acknowledges, "It didn't work perfectly."" "Three current and former government officials tell U.S. News that the satellite is still not up to par. Soon after it failed, Lockheed Martin engineers were able to save the satellite by tinkering with its software. The officials say Lockheed Martin was able to recover about 80 percent of the satellite's capability. But the satellite's crippled performance has resulted in many boardings of cargo ships that Navy officials mistakenly believed were controlled by suspected al Qaeda terrorists, says one of the sources." I interpret, "electronic circuit on the satellite had failed to work" as the failure of the deployment mechanism of the 3rd satellite. The recovery of "about 80 percent of the satellite's capability" "by tinkering with its software", also seems consistent with the loss of one of the three satellites. In any case, the upcoming launch should settle the question of the intended number of satellites. The probability of a second consecutive deployment failure must be incredibly small, so if once again we see only two NOSS, then that must be the intended number. I expect three, but we'll know soon enough. Ted Molczan ----------------------------------------------------------------- To unsubscribe from SeeSat-L, send a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@satobs.org List archived at http://www.satobs.org/seesat/seesatindex.html
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