yee@ames.arc.nasa.gov (Peter E. Yee) (07/30/88)
KSC SPACE SHUTTLE PROCESSING REPORT FPR - Friday, July 29, l988,
11:00 a.m.
STS-26 - DISCOVERY (OV 103) - PAD 39-B
T-0 for the Wet Countdown Demonstration Test (WCDDT) has
been tentatively set for 7:00 a.m. Monday morning, August 1. The
additional time is needed for troubleshooting and repair of
recirculation pumps in the Liquid Oxygen storage farm at Pad 39-
B, and the leak in the eight-inch liquid hydrogen feedline in the
tail service mast.
The T-0 for the WCDDT was targeted for 5:30 a.m. this morn-
ing but had to be terminated when console operators in the Firing
Room detected an unacceptable level of hydrogen in the tail serv-
ice mast 8-inch quick disconnect, and when one of the liquid
oxygen recirculation pumps would not start during chilldown of
the liquid oxygen delivery lines on the pad. Although there are
two recirculation pumps in the liquid oxygen system, the other
one was exhibiting possible RPM control problems.
The NASA Test Director originally determined a 48 hour tur-
naround would be necessary and later extended that to 72 hours.
The delay in the WCDDT means an equal delay in the Flight
Readiness Firing, which could be no earlier than 7:30 a.m.
Thursday morning August 4. However, this would be based on no ad-
ditional problems occuring between now and then.
At present, Pad 39-B is in a cleared condition for the
drainback and purge of the liquid hydrogen tank which was par-
tially filled during the test. The pad is scheduled to reopen at
4:00 a.m. Saturday morning. At that time engineers and tech-
nicians will be able to trouble shoot the hydrogen disconnect.
Although the pad itself is off limits due to the hazardous
nature of the detanking operation, workers will have limited
access to the liquid oxygen storage site and will begin work on
the recirculation pumps today.
The Rotating Service Structure will not be placed around the
shuttle vehicle until early Saturday morning.
The final determination of resumption of the WCDDT will in-
clude weather forecasts. At present a weather advisory for
lightning within 5 miles of the launch pad is in effect which
precludes any work in the pad area. Continuation of the advisory
and subsequent poor weather conditions could hold up work for ad-
ditional periods.