Re: Mix-ups about Mars '96 decay(s)

Alan Pickup (alan@wingar.demon.co.uk)
Wed, 10 Sep 1997 20:58:57 +0100

My understanding is that the object which re-entered over Chile and/or
Bolivia was, indeed, the Mars 96 probe but that it was never tracked by
USSPACECOM. From memory only, it may have re-entered early on November
17 UT, only a few hours after launch. This could have placed the local
date as November 16, consistent with the popular reports.

The object which was picked up by USSPACECAM was the Mars 96 Block D-2.
I posted predictions to SeeSat-L for it at the time (when at first I
guessed it to be Mars 96 itself). USSPACECOM catalogued it as #24656 =
96- 64 A and, as such, its decay date was reported as November 18 in the
Weekly Satellite Situation Report issued on November 21 (calling it Mars
96).

My own analysis suggested that the re-entry had occurred at about
November 18.041, ie at about 00.59 UTC on that day. As I reported in a
SeeSat-L posting on November 23 (probably still in the archives), my
SatEvo evolution over the final few orbits agreed remarkable well with
the OIG elsets and the state vectors published by the Russian Space
Surveillance Center. On the MARS96_5.HTM WWW page, the decay is given
(or was when I last looked) as atmospheric entry at Nov 18
01.13 UTC (ie November 18.051) and splashdown at 01.20 UTC (November
18.056).

I thought that that was the last we would hear of Mars 96. Until, out of
the blue, the Weekly Satellite Situation Report of 1997 March 20
announced that #24656 = 96- 64 A = Mars 96 had (also!) decayed on March
18 - maybe the Bolivians had thrown it back. I have checked every elset
issued by OIG since the beginning of 1997, but I can find no other
elsets for #24656. If USSPACECOM did, indeed, track a second object from
this launch to its decay on March 18 (and I don't believe they did) then
where in the catalogue is the object they and their Russian counterparts
tracked to its decay last November 18?

Alan
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