We are preparing to enter environmental testing. The spacecraft is scheduled for completion the end of next week. After that we will move to the EMI (electromagnetic interference) chamber for testing the week of March 23rd. The earth sensor is on the spacecraft. The star tracker will be installed tomorrow. The star tracker safe-to-mate and functional have already been performed, but we removed the tracker earlier in the week to perform some bench tests.
The left photo shows Mike Rodriquez inspecting the star tracker
shade with a special green light which makes the dust show up better.
Mike was cleaning the tracker prior to installation on the
spacecraft. The right two photos show Gary Cooper working on the
spacecraft last week. The star tracker has a star simulator on the
top of the shade, with some material over that to block stray light.
We use the simulator to check the functionality of the star tracker.
Both of the solar panels have completed thermal vacuum cycling.
The flash tests before and after cycling were virtually identical--the
solar array output power did not change. The solar arrays were temporarily
installed on the spacecraft this week for a deployment test. All went
well. The arrays will be installed on the spacecraft with flight
hardware next week. The photo shows Giulio Rosanova and John Lyons
with the -x solar array just prior to the flash test. The test is
performed in a special booth where we can heat the array to near its
expected operating temperature. The small solar cell
on the tripod in front of John is a reference cell used to measure the
output of the flash. We flash the arrays rather than using a
continuous source so that we don't overheat them.
We completed evaluation of the WIE electromagnetic emissions and found them acceptable. The WIE is on the spacecraft and ready for environmental testing.
Next week, we will install the thermal blankets and the transponder.
Previous updates:
August 18, 1997
October 20, 1997
October 31, 1997
November 7, 1997
November 14, 1997
November 21, 1997
December 5, 1997
December 23, 1997
January 9, 1998
January 16, 1998
January 23, 1998
January 30, 1998
February 6, 1998
February 20, 1998