Who checks the checker? I found a pesky error in my vector calcs. My independent calc is now in very close agreement with Rob Matson's numbers. It's a tedious exercise to subtract the sat-obs vector from the obs-sun vector to arrive at the sun-sat vector. Then you average the components of the obs-sun and sun-sat vectors to get the solar panel normals. The axis is the vector that is normal to the panel normals. What makes it tedious is that the RA and Dec's have to be transformed into i,j,k vectors and back again. I used my September 29 observation (0325 UT) and last night's observation (October 9 at 0340 UT). 20040 89 41A Superbird A 09/29 0325 17h19m00s -7d47.6m 10/09 0340 16h52m06s -7d08.1m Sun 09/29 0325 12h23.2m -2.50d 10/09 0340 12h59.6m -6.37d Normal to solar panel 09/29 0325 8h 52.3m +4d 23.8m 10/09 0340 8h 56.1m +0d 47.5m Rotation axis R.A. 14h 57.0m, Dec 14d 47m But correcting my error validates an earlier bit of guessing. On October 1 I wrote: >I think the axis is more or less in the plane of the orbit, and is pointing >a little to the "left" of the sun Which proves the maxim: If you give a monkey a keyboard, his keystrokes will, by random chance, eventually result in a correct deduction about satellites... :) ------------------------------------------------------------------------------ Jim Varney | 121^ 23' 54" W, 38^ 27' 28" N | Sacramento, CA Member, SeeSat-L | Elev. 31 ft. | Member, Sacramento Valley Astronomical Society |jvarney@mail2.quiknet.com ------------------------------------------------------------------------------