Superbird rotation axis

ROB MATSON (ROBERT.D.MATSON@cpmx.saic.com)
5 Feb 1997 19:30:06 -0800

I've taken a look at Rainer Kracht's observations of Superbird A (Norad
#20040, 1989-041A) and have computed a solar-panel normal vector at the time
of his first flash, as well as at the time midway between his first and last
flash:

(All times UTC)

2/1/97 17:28:30.00  16h 20m 54s   -7d 02' 50"
2/1/97 17:39:01.02  16h 26m 28s   -6d 49' 31"

(Note that since Rainer's last flash was flash #54, 17:39:01.02 corresponds to
a time halfway between flash #27 and #28.  The actual solar-panel normal
should be close to the 2nd line above, since this should theoretically be the
time when the sweep of the specular reflection centroid was closest to
alignment with Rainer's location.)

When compared with previous values (from Sept/Oct '96), it appears that the
satellite rotation axis has changed.  Further observations are needed to pin
down the current rotation axis.  --Rob