Thank you to all who reported observations. I enjoyed reading every one of your reports. It was a nice way for Titan IV to end its east coast career, and I am pleased that quite a few list members were able to see it. This preliminary elset is derived from 6 of 9 positional observations by Russell Eberst, Alan Pickup, Bjoern Gimle and myself, over about a 15 minute arc immediately following orbit insertion: Lacrosse 5 1 71001U 05016A 05120.05269919 .00001335 00000-0 10000-3 0 09 2 71001 56.9932 133.2207 0153942 13.3598 97.7461 14.93250618 09 WRMS residuals = 0.114 deg Perhaps some of the outliers can be salvaged with the aid of he preliminary orbit: 0501501 2420 20050430 010932.04 100900+324200 1.0 1.0 0 S 71001 05 620A 5919 G 20050430011441090 17 25 1649682+041623 29 S 71001 05 620A 5919 G 20050430011553210 17 25 1818182-044451 29 S I allowed all elements to vary except for drag; epoch is that of the final observation in the arc. This orbit will be revised somewhat with further observations, but it is very believable. Without a doubt, this is the initial orbit of a Lacrosse in a 57 deg inclination orbit. The argument of perigee results in apogee passes at the latitude of Diego Garcia, which is where I expect the orbit to be circularized about 48 h after launch, early on 2005 May 02, probably at 01:50 UTC (perhaps one rev earlier). That would be in keeping with the pattern established by Lacrosses 2, 3 and 4. Finally, I note that Lacrosse 5's plane is about 59 deg east of Lacrosse 3's, similar to Lacrosse 4's initial plane spacing 69.3 deg east of Lacrosse 2. One month ago, I argued that this approximate spacing was optimal, and expressed doubt that this mission was a Lacrosse, because the April 7 UTC launch period would not have supported it: http://satobs.org/seesat/Mar-2005/0294.html But then Lacrosse 3's planar precession during the subsequent 23 day launch delay brought about the optimal spacing (at least my idea of it) apparently by chance. The delay was due to problems with ground support systems, as reported in detail by Spaceflight Now: http://spaceflightnow.com/titan/b30/050420fixes.html This is a great example of how easy it is to read meaning into relationships that are merely coincidental. Ted Molczan ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Sat Apr 30 2005 - 03:43:39 EDT