yee@ames.arc.nasa.gov (Peter E. Yee) (08/01/88)
KSC Space Shuttle Processing Report -- Monday, August 1, l988
7:15.am
STS-26 -- Discovery (OV 103) -- Pad 39B
The Wet Countdown Demonstration Test of the Space Shuttle
Discovery was concluded with a T-0 at 6:56 a.m. this morning.
Drainage of propellants from the external was scheduled to begin
shortly after T-0, a process that will take about 18 hours to
complete. When drainage is completed, engineers will enter the
pad and begin troubleshooting a hydrogen leak discovered last
night early in the countdown in the tail service mast. The leak
caused suspension of hydrogen tanking at the 67 per cent mark.
There are conflicting indications as to whether this leak is the
same one which was manifested in the first tanking attempt or if
it is a different one.
Liquid oxygen loading was completed during the test, but problems
were detected in the recirculation pumps which also will be
investigated.
During the final minutes of the countdown, the count was halted
momentarily by the ground launch sequencer at the T-1 minute, 57
second mark when it detected less than the full liquid hydrogen
load. Engineers inserted a by-pass instruction into the computers
and the count resumed.
A number of special tanking tests scheduled during the countdown
were postponed and will be re-scheduled for the Flight Readiness
Firing. Turnaround for the FRF is expected to take between 72 and
96 hours. FRF could occur on either Thursday or Friday.