As a satellite observer since 1958, (about 32000 obs) here are some past and present reasons for observing. I speak as an observer, who occasionally determines orbits. I am a UK citizen, ex rocket scientist, who has worked on military contracts in the UK and USA. I like seeing newsworthy satellites. Mostly just for fun, but also to get info maybe not otherwise available. For example from watching the early Russian Salyut and Soyuz satellites you could tell if a Soyuz had docked. was close to Salyut, or nowhere near. If things were not going well, the Russians said nothing; the US military probably knew but said little. Magnitude variation of some satellites would tell if it was spinning, suggesting a failure. The fuel dumps from the Apollo moon launches were fascinating. Currently I watch ISS/Soyuz/Shuttle, Gorizonts and secret satellites. Up to about 1985 observations of selected satellites were used for: (a) determining air density (b) determining high altitude winds (c) determining harmonics in the earth's gravity (d) looking at how the spin of rotating satellites slows down. Satellites with orbits suitable for these purposes were given high priority for observers. The observations were analysed by UK universities and others. These studies stopped because of lack of money to pay for people to do the studies. None of these studies have any immediate practical use. They contribute to a general understanding of the earth and its atmosphere, which may be useful in the future. There may still be some analysis going on. It would be easier for someone to do such studies now (computers are cheaper), using either TLEs or observations or both. (c) above would benefit from lots of observations of a satellite near resonance. I used to observe a mixture of priority satellites, and any satellite I had not seen before. I still do this, but my priority satellites are now mostly US secret satellites. After 9/11 I followed the custom of not posting my observations of US military satellites on seesat. I still archived the obs to heavens-above, but at least a month later. How useful are our observations and orbits to rogue nations or terrorist groups? Clearly a static site can be seen anytime, so up-to-date obs/orbits would only be useful to avoid detection of events, If I (as a rogue dictator) wanted to conceal my missile test I might worry about spy satellites. One source of info would be seesat, but this would miss the satellites that seesat had not spotted. Could I be sure that unclassified satellites did not carry spy cameras? Probably some do. Cameras and radio receivers could be put into upper stage rockets used to launch non-military payloads. There are maybe 100 satellites that are operational spy satellites (all sorts and all nations). I (dictator) would not have a tracking system comparable to US or Russia, and could not trust that military data leaked by a friend in US/Russia was complete or accurate. I suspect that I would not bother to try to find a time when no spies were above, but would choose to do my tests under cover of darkness/cloud/ thunderstorm. My (real me) conclusion is that amateur obs & orbits are of limited value to dictators/terrorists. I support the view that space belongs to no nation, and ideally there should be no restrictions on publishing obs or orbits. In the real world I accept that my knowledge is incomplete, so some restrictions may be necessary. If a few tens of observers+analysts can maintain orbits on about a hundred objects, then a thousand people could track almost everything of significant size, using simple equipment. I predict that in a few years there will be several automated large field-of-view CCD or similar devices staring at the sky all night, sending what they see to PCs which will update orbits of expected satellites, and calculate orbits of unexpected ones. Finally I know (in the UK at least) secrecy is commonly used to prevent embarrassment to politicians, or to enhance the status of an official, rather than to prevent information being used by a potential enemy. Mike Waterman ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Wed Aug 11 2004 - 17:41:30 EDT