RE: OTV 5 search elements

From: Ted Molczan via Seesat-l <seesat-l_at_satobs.org>
Date: Sun, 5 Nov 2017 16:03:27 -0500
The search orbit I posted for the 63.6 deg inclined OTV 5 suspect is too far
in plane from the estimated 43 deg parking orbit of OTV 5, to have been
manoeuvred there by the Falcon 9 second stage. The burn angle would have
been nearly 45 deg, requiring an orbital manoeuvre with delta-V in excess of
5800 m/s.

Falcon 9 v1.2 is said to be able to send 5500 kg to GTO, with first stage
recovery. Delta-V to GTO is ~2400 m/s. 

The mass of X-37B is believed to be about 5000 kg, and OTV 5's Falcon 9
first stage was recovered. Performance to a 43 deg parking orbit would be
less than to 28.5 deg, so I doubt that the available delta-V in parking
orbit would be much more than the 2400 m/s of a GTO launch. Therefore, I do
not believe that a 5800 m/s plane change was feasible. I recall that OTV is
believed to have considerable delta-V of its own, but I doubt it would be
sufficient to make up the ~3400 m/s shortfall of Falcon 9.

Russell Eberst and David Hopkins report that the OTV 5 suspect was a no-show
in the search TLE that I posted, which casts serious doubt on the
reliability of that orbit.

Russell has suggested that his Nov 02 UTC sighting may have been of an old
NOSS object. NOSS 1-7 (E) (86014E / 16624) appears to correlate. I offer the
following search TLE:

1 77777U 77777A   17306.79899306  .00000911  00000-0  10280-3 0    06
2 77777  63.3235 189.6500 0900000  59.0987  43.7000 13.45667686    01

Ted Molczan


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Received on Sun Nov 05 2017 - 15:04:14 UTC

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