MISSION CONTROL CENTER
STS-67 Status Report #4

Friday, March 3, 8 a.m. CST

Science operations continued overnight as the Astro-2 instruments
collected information on supernovas and white dwarfs from Endeavour's
payload bay.

The Instrument Pointing System continues to perform well. The
preliminary assessments of IPS stability and accuracy show that the
system is operating well. Control loop software, gyro and
accelerometer response have been good, and Optical Sensor Package
performance has been excellent with two of three trackers slightly
exceeding performance expectations. IPS controllers in Houston are
currently tracking no problems or issues, and team members do not
anticipate a change in the IPS's performance.

The payload control team at the Marshall Space Flight Center,
Huntsville, Ala., however, is looking at several reported excursions
in ASTRO-2's pointing abilities that have required the crew to
repeatedly fine tune the instruments after establishing the platform's
reference point for celestial observations. Controllers in Houston and
Huntsville are working on procedures that will reduce the number of
calibrations needed.

Throughout today, crew members will continue their ASTRO-2
observations and will set up the Middeck Active Control Experiment for
the first time. MACE is designed to measures and control the dynamics
of complex systems in the microgravity environment of space.

Endeavour is in excellent condition with no mechanical problems in an
orbit of 190 by 188 nautical miles, completing one orbit every 91
minutes.

--end--