OTV 3 elements

From: Ted Molczan via Seesat-l <seesat-l_at_satobs.org>
Date: Tue, 12 Aug 2014 12:04:42 -0400
This TLE is based on observations by Cees Bassa, Kevin Fetter, Alberto Rango and myself:

OTV 3                                                    319 X 382 km
1 39025U 12071A   14223.82863608  .00024143  00000-0  15546-3 0    04
2 39025  43.5037 153.7150 0046654  48.2396 312.2455 15.73630149    03
Arc 20140809.05-0811.85 WRMS resid 0.020 totl 0.009 xtrk

I received Alberto's observation of last night in time to include it in this analysis.

As of the latest observation, by Cees on Aug 11 at 20:20 UTC, OTV 3 had not resumed its usual frequent manoeuvres to
counteract the effects of drag. If it does so, then it will begin to run progressively late against these elements.

Brad Young reported OTV 3 a no-show on the pass predicted for Aug 12 at 02:25 UTC. He began observing 2 min earlier and
continued long afterward. It could conceivably have been unusually faint. It could also have manoeuvred. 

On the two previous missions, the lowest mean orbital altitude was about 285 km, and the manoeuvre to that altitude
occurred not long before landing (~a few weeks). In the case of OTV 2, the inclination was reduced from 42.8 deg to 41.9
deg.

There was plenty of time in the six hours after Cees observed it, to make the required pair of manoeuvres and for the >2
min. time difference to accumulate. The following example is based on a manoeuvre within range of AFSCN stations VAFB
and Colorado RTS on Aug 11 at 23:10:22 UTC, at perigee, to reduce the apogee by ~100 km, followed by a circularization
burn at 23:51:46 UTC, over 27.451 S, 47.385 E:

                                                         284 X 285 km
1 70000U          14223.99428241  .00024143  00000-0  15546-3 0    09
2 70000  43.5037 152.7158 0001000  49.3789 172.3913 15.97000000    09

I did not change the inclination. Of course, there are many other possibilities, including no manoeuvre. It may simply
have been much fainter than normal.

Ted Molczan


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Received on Tue Aug 12 2014 - 11:05:38 UTC

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