[sci.space.shuttle] Launch Advisory for 04/11/90

yee@trident.arc.nasa.gov (Peter E. Yee) (04/12/90)

STS-31/HST SCRUB TURNAROUND STATUS
Wednesday, April 11, 1990 - 3:00 p.m. EDT



NASA and contractor personnel continue processing of Space 
Shuttle Discovery and the Hubble Space Telescope following 
the launch scrub of the STS-31 mission at 8:46 a.m. EDT 
yesterday.

No new launch date has been determined.  Launch delay 
estimates continue to be approximately 7-14 days.  Engineers 
are looking at both APU #1 and its controller as part of their 
efforts to determine the cause of yesterday's problem.  All 
indications point to a problem in the APU but the controller 
will be checked to assure it is not the problem.  Procedures for 
APU removal and options for recharge of the HST batteries 
are being reviewed.

Immediate processing work will involve extending the 
Rotating Service Structure, installing access platforms and 
removal of the controller for APU #1.  The controller will 
be sent to the contractor to verify that it did not cause the
intermittent chamber pressure indication.

The decisions on whether or not to remove and replace the
APU and the procedures for HST battery recharge are 
expected either late tomorrow or Friday.