STS-77 Mission Control Center
Status Report #17

Monday, May 27, 1996 -- 7 a.m. CDT

The third rendezvous with the small aerodynamically stabilized
satellite went by the book this morning as Commander John Casper and
Pilot Curt Brown guided Endeavour to just under 2,000 feet from the
cylindrical shaped PAMS-STU satellite.

While the orbiter's payload bay was pointed carefully toward the
satellite, payload controllers at NASA's Goddard Space Flight
Center sent commands to an on- board Attitude Measurement System (AMS)
to try to calculate the satellite's attitude to within a tenth of a
degree of accuracy.

The crew was given permission to move within 1,650 feet and
controllers verified the laser was hitting the reflectors on the
satellite, confirming that the Shuttle was pointed correctly.

The mechanism which swivels the AMS to the proper position was slowly
moved through various positions to lock on to the satellite to gather
attitude data.  The PAMS-STU (Passive Aerodynamically Stabilized
Magnetically Damped Satellite - -Satellite Test Unit) was deployed
from a small canister in Endeavour's payload bay Wednesday in an
unstable, slightly tumbling attitude to observe how or whether it
could stabilize itself without using satellite lifetime-limiting
propellants.

The technology demonstration experiment has, according to engineers,
proven the concept of propellent-free satellite stabilization based on
comments from the crew during three separate rendezvous.

Endeavour's close encounter with the PAMS-STU is scheduled to last
until about 9 this morning before a final separation maneuver is
conducted. The satellite is expected to reenter the Earth's
atmosphere and burn up in about a month.

Casper was scheduled to take time out during the final phase of the
rendezvous to talk to fellow astronaut Shannon Lucid and her two
cosmonaut crewmates aboard the Russian Space Station Mir at about 8:25
this morning.  The conversation was scheduled as the two vehicles
passed within about 900 miles of one another over New Guinea and the
Philippines.

Late today and tomorrow the crew will wrap up science investigations
and begin shutting down experiments and packing up the orbiter for
Wednesday's planned return to Earth.  Landing is currently
scheduled for 6:12 a.m. Central time at the Kennedy Space Center in
Florida.

Endeavour's eleventh mission is in the homestretch with all systems
in excellent shape.  The crew will go to bed at 1:30 this afternoon
and will be awakened at 9:30 tonight.

The JSC newsroom is open around the clock throughout Endeavour's
STS-77 mission.