Allen, Dave Ransom puts out a disk (CD-ROM), if you call his BBS or write him mail I am sure hge could get you some info on the TLE archive CD.. ---- Josh R. Williams ** JRW Satellite Page ** E-Mail: sponge@nebula.net URL: http://www.nebula.net/~sponge/ --------------------------------------------------------- Latitude: 41 deg 59' 29" N -- Longitude: 83 deg 27' 41" W On Mon, 19 Feb 1996, Allen Thomson wrote: > Bart De Pontieu said: > > >A friend of mine is working on data obtained by the IRM-1 satellite, which > >was part of the AMPTE-project. IRM-1 was built at our institute (MPE) and > >she told me IRM-1 had burnt up in the atmosphere. But in the last Satellite > >Situation Report I found this entry: > > >15200 84-088B IRM 1 (AMPTE) FRG 2653.1 27.0 13808 402 > > >The original orbit was one with an apogee of 120000 km and apogee of 560 > >km. > > [snip] > > >Maybe it *did* decay without Spacecom knowing about it, since > >they don't track it frequently ?? > > >I could check this if I had access to older SSR's, but they do not seem to > >be available electronically before 1993/1994? Can anyone confirm this ? > > >More generally, I think it would be really interesting to have an archive > >of old elements of satellites available electronically. Old elements are very > >useful for research purposes, and I presume Spacecom has them stored > >somewhere. Maybe someone who has influence with Spacecom could persuade > >them to make old elements available ? > > >Maybe Spacecom or OIG are already working on this ? > > >Anyone know ? > > > This is weird, even for Spacecom, which isn't known for rigor in > its maintenance of orbital elements (I blush for my country ;) ). Here > is the "last five" download for 1984 88B from NASA Goddard, done today, > 19 Feb 1996: > > Element set number = 1 > 1 15200U 84088B 85165.07498243 -.00000353 +00000-0 +10000-3 0 05776 > 2 15200 027.0326 344.5409 8932020 038.8095 018.6999 00.54276908001640 > Element set number = 2 > 1 15200U 84 88 B 85165.07494771 -.00000323 00000-0 99999-4 0 1709 > 2 15200 27.0326 344.5409 8932020 38.8095 18.6999 0.54276908 1640 > Element set number = 3 > 1 15200U 84 88 B 95165.07498243 -.00000323 00000 0 99999-4 5778 <-- ! > 2 15200 27.0326 344.5408 8932020 38.8095 18.6999 0.54276909 1640 > Element set number = 4 > 1 15200U 84088B 85165.07493614 -.00000428 00000-0 10000-3 0 3640 > 2 15200 27.0326 344.5409 8932020 38.8095 18.6999 0.54276908 1640 > Element set number = 5 > 1 15200U 84 88 B 85165.07495928 -.00000327 00000-0 00000+0 0 347 > 2 15200 27.0326 344.5409 8932020 38.8095 18.6999 0.54276908 1640 > > > Objects in such highly elliptical orbits typically > experience strong lunar/solar perturbations which cause the > perigee to fluctuate significantly. I'd guess IRM is long dead, > despite the "95165" epoch in the third element set. > > As for historical data sets, it would be nice if Spacecom or > NASA would issue a CD ROM archive, but I know of no serious > effort to do so. The total volume of data isn't particularly > daunting: a ludicrous upper bound (LUB) can be estimated by > assuming that 1e4 objects have been tracked once per day since > 1958, generating one 140 byte element set per object per day: > 1e4*1.4e2*3.65e2*3.8e1 ~= 19 gigabytes. Compress this with > pkzip or similar to get ~7.5 Gbytes: a dozen current CD ROMs, > one or two of the new generation (I don't remember what they're > called). In reality, I'm sure the amount of data is less than a > quarter, quite possibly less than a tenth of this LUB estimate. > > One possibility for justifying a request for blanket release > of the element sets could be that time-series analyses of > satellite orbits can be used to monitor the upper atmosphere. > Global change studies might find this sort of information > useful. (Now that I've said that, the name "Al Gore" comes to > mind -- the US VP has pushed in the past to have other Cold War > data released for scientific use, and might do so in this case.) > > Short of the Vice President, Prof. Tom Kelso > (tkelso@afit.af.mil) of the Air University at Maxwell AFB in > Alabama is the person who seems best able to divine what is and > isn't possible at Spacecom, so I'd suggest asking him about a > Grand Archive project. > > Finally, It might be worthwhile to ask the Russian Space > Forces about their orbital element archives -- they have a home > page linked to IKI's. > >