Flashing USA 33?

Thu, 16 May 96 14:11:48 PST

Last Thursday, May 9, about 21:25 PDT, I observed USA 33 (KH-11, 88-099A).  It 
was flashing with a period of about 12 sec.  This was kind of surprising, since 
I had observed this object several other times, and I hadn't noticed any 
flashing.  In fact, this was the first time I'd ever seen a satellite flashing 
at all.  Unfortunately, I wasn't expecting it to vary, so I don't have a very 
accurate estimate of the period - just by counting.  Not being very good at 
estimating magnitudes of stars, let alone moving satellites, I would hesitate to 
hazard a guess at the magnitude variation (maybe between 2 and 5?).

Anyway, I though that was kind of neat.  I went out the next night all set to 
measure the period and hopefully get a decent magnitude estimate - but this time 
it was totally steady.

The PPAS lists about 25 observations, most of which are steady.  There are 3 
observations of variable magnitude, with periods of 10, 15, and 78 seconds.

Does anybody know what's going on here?  Are there any other satellites which 
exhibit this kind of behavior?

Stu Huston                 
There is no great genius without a tincture of madness.
-- Seneca: De Tranquillitate Animi, 15.