STS-76 Mission Control Center 
Status Report # 15

Friday, March 29, 1996, 6:00 a.m. CST

With the Mir Space Station some 60 nautical miles behind them, the
Atlantis astronauts are preparing for tomorrow's return to Earth.

Overnight, Commander Kevin Chilton, Pilot Rick Searfoss and Mission
Specialist Rich Clifford performed a routine checkout of Atlantis'
flight control surfaces, using a circulation pump instead of an
auxiliary power unit to route hydraulic fluid to the ailerons,
elevons, speedbrake and rudder used during reentry. Mission Managers
elected not to power on the APUs prior to entry to preserve them for
use during Atlantis' return to Earth.

Auxiliary Power Units 1 and 2 will be powered on as they normally are,
with APU3, the system associated with the leaking hydraulic unit,
turned on late in reentry and run in a low pressure, low speed mode
for use only as a backup system if needed.  All three hydraulic
systems are expected to be in good working order to support
Atlantis' landing.

During a hot-fire test of the orbiter's reaction control system
jets early this morning, three of the 38 primary jets failed, with one
leaking fuel. The crew closed the left aft manifold and stopped the
leak.  The loss of these three jets has no effect on tomorrow's
planned landing since each has at least two jets in the same positions
that can perform the same functions.

Today, the astronauts will continue stowing some of the final transfer
items received from the Mir-21 crew and the equipment and checklists
they have used during their seven days on orbit as they ready Atlantis
for landing. Mission Specialist Linda Godwin will continue to work
with the European Space Agency Biorack located in the Spacehab module
before closing out the module for the final time tonight.

Atlantis is now scheduled to land at 6:57 a.m. CST Saturday at the
Kennedy Space Center. A second opportunity to land at KSC also exists
on Saturday, with an 8:33 a.m. CST touchdown.  Edwards Air Force Base
in California is not being called up to support tomorrow's landing
attempts, but should weather preclude a Saturday landing at KSC, both
sites will be available for a Sunday landing.

Weather conditions Saturday at KSC are expected to be good for
landing, with only a slight concern for early morning ground fog.
High winds and thunderstorms are expected to move into the area on
Sunday. Weather at Edwards Air Force Base is predicted to be
acceptable on Sunday.  A total of five opportunities are present for a
Sunday landing, two to KSC and three to Edwards.

All systems on board Atlantis are continuing to perform well.