NASA viewing predictions

Fri, 8 Aug 1997 07:41:57 -0500

In some part I am responsible for the current criteria used to generate
the shuttle viewing predictions. The NASA PAO office at MSFC, then later
JSC, generated the initial predictions at the beginning of the program
which were often out of date and unreliable. I pointed out numerous
errors as each mission flew.  Around 1984, as a long time satellite
observer, I offered to generate predictions for them on the side.  I
developed a national and international cities list and began to provide
those predictions until around 1988. At that time I changed jobs and the
Flight Dynamics folks offered to pick up the prediction generation task
at JSC. The JSC PAO office was reluctant for this transition, but the
NASA Flight Director office that I supported required me to hand it
over, since I work for a contractor company here.  We had a long meeting
in which I outlined my criteria for the general public and they adopted
it. As P. Chien stated earlier, the goal here was to meet the viewing
critieria of the average person on the street, not the serious satellite
watcher. That is still the objective. However in the last 7 years or so
they have modified the criteria as they saw fit and I have stayed out of
the loop.

Anyway, the criteria were a bit wider than Craig noted and the minimum
elevation was indeed around 30 degrees, the bandwidth of time was 45
minutes from sunrise and sunset as latest/earliest view times. The
bottom line is that if SEESAT-L subscribers are interested in
predictions that allow them to push the limits (minimum elevation,
viewing in daylight, etc.) they should not expect NASA to provide them,
but rather use their own prediction programs and set their own criteria.
Judging from the observations reported here, people are doing just that
and it is a pleasure to see so many Shuttle observations being
successfully made.

Paul D. Maley
DO5/Cargo Operations
NASA Johnson Space Center
Houston TX 77058 USA
phone: 281-244-0208
fax: 281-244-7622
latitude 29.5378 north; longitude 95.0868 west; altitude 6 m