glints

Walter Nissen (dk058@cleveland.Freenet.Edu)
Tue, 9 Apr 1996 05:58:48 -0400

>I've got my own little theory.  What are the most notorious glinters?  UARS, 
>Tiros, DMSP.  What do they all have in common?  Single solar panels on a 
>single actuator arm.  My theory is that the simple arm is not a full helio- 
>stat and doesn't track the sun all the way down to low angles such as at 
>sunset.  So we get glints.  Theory (c)Jim Varney. 
 
Here are all of the "glints" from my list of bright objects, sorted by 
SPACECOM #, and hence, age: 
                                mag      glint mag 
Atlas Centaur 2  00694  63- 47A 3       *2 
M* 1- 4          04393  70- 37A 4       *1 
SeaSat 1         10967  78- 64A 2       *0 
Tiros N          11060  78- 96A 4 or 5  *2 
NOAA 7           12553  81- 59A 4       *2 or 3 
NOAA 8           13923  83- 22A         *2 
1515             14551  83-122A 4       *1 
1626             15494  85-  9A 3.5     *2 
1703             16262  85-108A         *0 or 1 
1908             18748  88-  1A 4 or 5  *3 or 4 
1933             18958  88- 20A 2       *1 
USA 32           19460  88- 78A 3       *1 or 2 
1975             19573  88- 93A 4 or 5  *3 
Lacrosse 1       19671  88-106B 1       *0 
1992 r           19770  89-  5B 4 or 5  *3 or 4 
HST              20580  90- 37B 2       *-1 or -2 
Lacrosse 2       21147  91- 17A 1       *0 
Nadezhda 3 r     21153  91- 19B 4       *2 
UARS             21701  91- 63B 1       *-1 
USA 81           21949  92- 23A 3       *2 
Topex            22076  92- 52A         *3 
 
C* 1515, 1626, 1703, 1908, 1933, and 1975 are all identified as Tselina 
objects by Rainer Kracht. 
 
My observational experience does not support the idea that the notorious 
glinters are UARS, Tiros and DMSP. 
 
When I think of glints, I think of HST, SeaSat, Tselina (including lately 
observed objects not yet in the list), Topex, SROSS-C2 = 23099 = 94- 27A, 
DMSP F3 = AMS 3 = DMSP B5D1-3 = 10820 = 78- 42A, STS, Mir, Lacrosse, USA 
32 and 81 and Tiros N.  These seem to divide into 2 categories, the active 
and the inactive.  HST, Topex, STS (at the times observed), Mir, Lacrosse, 
USA 32 and 81 are active.  The others appear to have been inactive at the 
times that glints have been observed (I'm still looking to confirm this; 
anyone who has dates of operation for the Tiros/NOAA and Tselina 
satellites will be gratefully received).  The active satellites I mention 
don't correspond well to UARS, Tiros, and DMSP.  I have seen UARS glint. 
Tiros may be ambiguous; despite many attempts, I haven't seen the older, 
smaller ones; the newer ones, including the NOAA's, I haven't seen glint 
until they are older (and no longer operating?). 
 
The active satellites I have seen glint all seem to have an excuse other 
than that offered by Bart and Jim.  HST has that very long tube.  Topex 
has been observed to glint off its large bottom surface (note to those 
trying to observe it: these glints have been observed when it is at a very 
unfavorable phase angle; as a result it is hard to see when "favorable" 
and occasionally bright when it is supposedly nearly invisible).  STS 
orbiters have the shiny payload doors.  Mir has a flock of solar panels at 
various (inoperative?) angles and lots of long tubes.  The Lacrosses 
emit(?) visible light described as red or yellow.  UARS could be glinting 
off its long boom or one of its large surfaces.  USA 32 and 81 sometimes 
flash (glint?) rapidly in a manner inconsistent with a deployed, 
stabilized, somewhat misdirected solar panel. 
 
I'm not saying Bart and Jim's theory is wrong (or theories if they are 
distinguished).  I'm merely saying I haven't seen (any? many?) glints 
that seem to be so caused, and I don't see a stream (any?) of such 
observations from others.

Cheers.

Walter Nissen                   dk058@cleveland.freenet.edu