Re: Incorrect Chandra TLE?
Tony Beresford (starman@camtech.net.au)
Thu, 19 Aug 1999 13:59:33 +0930
At 11:41 19/08/1999 , Ron Lee wrote:
>CXO
>1 25867U 99040B 99219.38932609 -.00000028 00000-0 00000+0 0 137
>2 25867 28.4718 194.5545 7750893 272.2645 23.4010 0.94210851 189
>CXO
>1 25867U 99040B 99216.69385420 -.00000056 00000-0 00000+0 0 110
>2 25867 28.4570 194.5520 8468509 270.6770 180.2770 0.39254669 134
>
>Maybe I am missing something but how did the mean motion go from 0.392
>to 0.942? I suspect the top TLE is in error.
The set with meanmotion .392.. is in fact a later elset if you look at
the appropiate column. Its just that SPACECOM had to set the epoch
at the ascending node, which was unfortunately earlier the last one.
I have already pointed this problem out.
An additional problem is that the TLE is not current. It doesnt represent
the position of the CXO, because it doesnt include the effect of the final
burn. The final orbit state vector was posted to Seesat by Jonathon Mcdowell,
and Ted Molczan posted the converted TLE a few hours later
Chandra 15.0 4.0 0.0 4.2 d
1 25867U 99040 B 99219.45833333 .00000000 00000-0 00000-0 0 05
2 25867 28.4518 194.1107 8016020 271.0755 180.3370 0.37800574 01
Obviously USSPACECOM hasnt tracked it for the last 12 days or 4.5 revs, which
is a bit surprising as it is only mag 15.5 at apogee according to highfly
Tony Beresford