New NEAR glint UTs - 16:02:52 & 21:28:03

Dunham, David W (
Fri, 09 Jan 1998 11:44 -0500 (EST)

     In the message I sent about half an hour ago, I made an error in
the light-time correction, and a typographical error in the text.  The
expected times as seen from the Earth for the NEAR sunglints should be
16h 02m 52s (now past - sorry, but at least it's within the time I
stated in my original message) and 21h 28m 03s U.T., probably accurate
to a few seconds.  The rest of my earlier "NEAR sunglints - 16:02 . ."
message is copied below so that it can just be replaced with this one.
The S/C slew rate at the possible glint times will be about 0.4
deg./sec., so the duration of any glint will be about a second.  Note
that the 2nd glint will occur nearly 2 hours earlier than information
that I distributed earlier, so that a new view of the Earth, and new
topocentric calculations, will be needed for it, and will be posted
later on NEAR's Web site.  The predictions also show that the sunglint
will miss the Earth by about 1.2 deg. for both events, but especially
the 2nd one has several tenths of a deg. of uncertainty, at least. In
addition, Sun sensor data indicate that the perpendiculars of NEAR's
solar panels may very well be tilted over a degree from the S/C's "Z"
axis, so a glint, possibly 1/4th as bright as the 12.4 mag. that I
predicted (that is, one solar panel instead of all four), or maybe even
2 glints like that, are possible.  Also, the 91% sunlit waxing Moon is
inconveniently located only 8 deg. west and a little south of the field.
     Courtney Ray supplied the details for the information above.
Good luck with your observations - in spite of the problems, I hope
someone sees, and perhaps records, something.
       David Dunham, NEAR Mission Design