Dan Deak wrote: >Following the recent discussion about the explosion of 1999-057C, I used >the available elsets (debris E to AH, #26118 to 26145) to generate a 3D >plot using SatSpy of the actual position of all these debris at 23:25 UT on >April 16. > >It shows most of the debris are already scattered all around the orbital plane. >Interestingly, all the orbits intersect roughly at the same point. >(Question to analysts :) Could this be the place where the breakup occured ? Yes. If an explosion occurs at a particular point, then all the resulting pieces will have orbits that pass through that point. However, those that have significant air drag will not pass through that point after a month has gone by. Also there will be slight differences in the amount of precession of the node and argument of perigee values since the different pieces have different eccentricities and inclinations. So what has been a rather easily identified point in space and time for similar events in the past may not be so easily identified this time since it happened a month ago. But if you take 2 or 3 or 4 elsets that have rather divergent values (but have nearly-zero air drag) and put them into a "closest approach" program, you might be able to identify the exact time and place that the explosive event occurred. Hmm... none of them really have near-zero air drag. The current elset for the original rocket has the lowest and still a fairly circular orbit. I would assume that it is still 90% of the original mass. So try to intersect one of the fragments with it. CBERS 1 LM4 r 6.0 2.5 0.0 5.0 d 14 1 25942U 99057C 00099.29961658 .00001536 00000-0 43474-3 0 818 2 25942 98.5324 175.8837 0011972 225.3371 134.1183 14.46955064 25616 The lowest air drags: 1 26119U 99057F 00104.23383080 +.00003572 +00000-0 +31883-2 0 00017 2 26119 099.3728 179.1749 0527633 159.4036 202.9202 13.35675658004034 1 26121U 99057H 00104.94449767 +.00007299 +00000-0 +12439-2 0 00020 2 26121 098.6939 183.5196 0096734 338.9167 020.7964 14.66280322004520 1 26123U 99057K 00104.89995683 +.00006702 +00000-0 +21298-2 0 00020 2 26123 098.5404 181.1216 0085235 190.0576 169.8908 14.38167943004424 1 26143U 99057AF 00105.16477439 +.00002567 +00000-0 +22722-2 0 00092 2 26143 099.0184 178.6627 0500566 143.9658 219.6331 13.40366526003356 Try for a closest approach about 35 days ago? Obtain an elset for 99 57C from just before and just after the event and run a closest approach for those two? March 9 ok: 1 25942U 99057C 00069.14898026 +.00001603 +00000-0 +45410-3 0 00803 2 25942 098.5373 145.5131 0012467 316.9224 043.0989 14.46866365021269 March 16 slightly changed orbit: 1 25942U 99057C 00076.13359437 .00001386 00000-0 39570-3 0 761 2 25942 98.5354 152.5501 0012289 295.8827 58.2073 14.46692961 22276 In fact, you can even play around with Quicksat (radio predictions!) and come up with: Lat: 80 Long: 90E *** 2000 Mar 11 Times are PM UT H M S Tim Al Azi C Dys F Hgt Rng 26119 99057F 12 21 1 1.2 89 206 C -33 6 931 932 26143 99057AF 12 22 6 .9 90 49 C -34 6 882 882 26123 99057K 12 23 17 1.5 86 26 C -33 4 523 524 25942 CBERS-1 Rk 12 23 56 .0 86 26 C 2 4 474 475 12 24 0 .4 86 27 C -28 4 474 475 12 24 41 .0 86 27 C -5 4 474 475 26121 99057H 12 25 21 1.6 87 26 C -33 0 389 390 And then: Lat: -65 Long: 50W *** 2000 Mar 11 Times are PM UT H M S Tim Al Azi C Dys F Hgt Rng 26119 99057F 13 7 56 1.2 62 285 C -33 0 465 522 26123 99057K 13 8 7 1.5 64 284 C -33 9 459 506 25942 CBERS-1 Rk 13 8 14 .0 64 284 C 2 8 465 513 13 8 18 .4 64 284 C -28 8 465 513 13 9 0 .0 63 284 C -5 8 466 516 26143 99057AF 13 8 17 .9 63 285 C -34 0 476 528 26121 99057H 13 8 57 1.6 63 284 C -33 5 470 521 So March 11 about 13:08 hours UT must be close. Mike McCants ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Mon Apr 17 2000 - 09:26:20 PDT