21667 / 91 59B / Cosmos 2154 Rk continues to accelerate

Mike McCants (mike@comshare.com)
Mon, 12 Feb 1996 01:25:07 -0600

I observed 91 59B on Feb. 8 (1:09UT) at 17.0 seconds and this evening,
Feb. 12 (1:16UT) at 12.5 seconds, so I believe it is still accelerating.
I think it will still be visible in the evening sky from northerly
latitudes for a while.

Here are the last 5 elsets from OIG:

1 21667U 91059B   96037.07632945  .00000402  00000-0  40915-3 0  7713
2 21667  82.9029  56.2438 0025248  28.9641 331.2972 13.74311364223673

1 21667U 91059B   96038.09558278 +.00000707 +00000-0 +73165-3 0 07779
2 21667 082.9026 055.4848 0025183 026.5682 333.6796 13.74315664223816

1 21667U 91059B   96039.04202502 +.00001204 +00000-0 +12584-2 0 07782
2 21667 082.9020 054.7797 0025216 023.2474 336.9883 13.74322450223943

1 21667U 91059B   96039.11482757  .00001209  00000-0  12637-2 0  7731
2 21667  82.9020  54.7255 0025192  23.0402 337.1887 13.74322679223955

1 21667U 91059B   96040.42528453 +.00001627 +00000-0 +17057-2 0 07758
2 21667 082.9026 053.7519 0025039 020.2231 339.9928 13.74330601224133

The change in mean motion indicates a "drag" term that would be about
twice as high as what appears on the elsets.  The change is largest
between the last two elsets.

------- different subject hiding in the same message:

In early January, Bart posted:

>It would be interesting to have recent observations of 75- 82 B and 75- 82 A.
>If NORAD hasn't switched them by now, I would be willing to bet a lot of
>money on it that 75- 82 A will be faint and steady, and 75- 82 B will be
>flashing with a flash period well below 10 s. 

I observed 8352 / 75-82B / ??? this evening.  When I first spotted it, it
gradually grew in brightness to about 5th magnitude.  It was orangish.
Then it faded down to close to my limit - about 9.5.  It stayed there
for about a minute, then gave a "slow" flash to about magnitude 3.
This flash was white.  It went back down to 9.5 and stayed there for
another minute.  Then it came up to about magnitude 5.5 for about 6 seconds.
It was again orangish.  Then it went down so faint I couldn't track it.
(Shadow entry was to occur soon, so perhaps that's why I lost it.)

So, my opinion is that this is ETS-1, the payload, not the rocket.
But it appears to have a period of about 128 seconds, so Bart owes me
a beer next October.  :-)

I also observed UME 2 (78-18B) and UME 2 Rk (78-18A) later this evening
and I believe the flashes and faintness between flashes for 75-82B
are much more consistent with its being the payload instead of the
rocket.

Mike McCants
mike@comshare.com