STS-125/HST SM-4 Status Report No. 21 (Forwarded)

STS-125 MCC Status Report #21
Mission Control Center, Houston, Texas
Thursday, May 21, 2009, 5 p.m. CDT

As Atlantis' crew prepares for landing Friday, mission managers are closely
monitoring a low pressure system that has brought 16 inches of rain in three
days to the Shuttle Landing Facility at Kennedy Space Center in Florida.

Forecasters report the system is slowly moving away but it could still bring
more rain, possible thunderstorms and winds that could violate the shuttle's
flight rules into the Florida spaceport area. The two Friday landing
opportunities are at 9:00 and 10:39 a.m. CDT.

Should mission managers wave off landing the next four opportunities will be
Saturday with two at Kennedy and two at Edwards Air Force Base in
California. The opportunities at Kennedy are at 8:16 and 9:54 a.m. With a
favorable California forecast, the opportunities there are at 9:46 and 11:24
a.m.

In another first for spaceflight, the STS-125 crew testified before the
Senate Appropriations Committee, Subcommittee on Commerce, Justice, Science
and Related Agencies, chaired by Senator Barbara Mikulski of Maryland. She,
and former astronaut Sen. Bill Nelson of Florida, talked with the crew.

The STS-125 crew is the first to testify live from space in a Senate
hearing. Astronaut John Phillips gave the first congressional testimony live
from space on June 14, 2005, during Expedition 11, when he testified before
the House Science Committee, Subcommittee on Space and Aeronautics.

The crew also talked with reporters from ABC, FOX, CBS, NBC and CNN.

In preparation for landing, Atlantis' crew tested the ship's flight control
surfaces and reaction control system thrusters. Both systems functioned well
and are ready to support entry activities.

Tomorrow, the crew should begin deorbit preparations at 3:50 a.m. and close
the payload bay doors at 5:10 a.m. Here are predicted times for tomorrow and
Saturday's landing opportunities (all CDT):

ORBIT SITE D/O BURN LANDING

FRIDAY 165 KSC 7:49:16 a.m. 9:00:31 a.m.
166 KSC 9:33:41 a.m. 10:39:18 a.m.

SATURDAY 180 KSC 7:02 a.m. 8:16 a.m.
181 EDW 8:29 a.m. 9:46 a.m.
181 KSC 8:46 a.m. 9:54 a.m.
182 KSC 10:12 a.m. 11:24 a.m.

The crew is due to go to sleep at 5:01 p.m. and will wake at 1:01 a.m. to
begin the procedures for landing. The next status report will be issued at
the beginning of the crew's day or earlier if events warrant.