[sci.space.shuttle] Shuttle Status for 09/19/90

yee@trident.arc.nasa.gov (Peter E. Yee) (09/21/90)

            Wednesday September 19, 1990                   11:00 a.m. EDT


                     KSC SPACE SHUTTLE PROCESSING STATUS REPORT

          -----------------------------------------------------------------

                     STS-35  --  Columbia (OV 102)  -  Pad 39-A


               The orbiter Columbia's Power Reactant and Storage
          Distribution System tanks have been drained of their liquid
          hydrogen and liquid oxygen reactants. A purge of the system is
          complete and the pad is open for extended scrub turn-around
          operations.

               Work is currently underway to gain access to the aft
          compartment. Aft inspections will be halted later this afternoon
          for pad clear operations to off load hypergolics from the shuttle
          vehicle OMS/RCS system. This will be followed by vehicle ordnance
          disconnect operations.

               The payload bay doors are scheduled to be opened shortly
          after 12:00 noon today. Payload standdown operations will begin
          once the pad is reopened for general work tomorrow morning.

               Engineers continue to make preparations for a liquid
          hydrogen tanking test on Columbia, however, no specific date has
          been established for the exercise.



                      STS-41 -- Discovery (OV 103)  -  Pad 39-B


               Work at pad B is underway for a planned main engine flight
          readiness test. Call to stations for the test will occur at 8:00
          a.m. Thursday. This operation will allow technicians an
          opportunity to test the main propulsion system aerosurfaces and
          cycle the main engines in the manner used for flight.

               Today at the pad, workers are in the process of removing the
          high pressure fuel duct and bleed valve on main engine number 2.
          Operations should be complete by end of shift tonight in time for
          the flight readiness test tomorrow.

               Engineers are currently planning a helium signature test on
          the shuttle's liquid fuel feed lines on Saturday.

               The Launch Readiness Review is on going this morning at KSC
          to discuss the readiness of the STS-41 launch team. The Flight
          Readiness Review is scheduled for next Monday and Tuesday.
          Following this review, release of a specific launch date is
          expected.


                      STS-38 -- Atlantis (OV-104)  -  OPF Bay 2


               Freon coolant loop number 1 vacuum and moisture checks are
          in work today. The orbiter is scheduled to be transported to the
          Vehicle Assembly Building at the end of this month.

tif@doorstop.austin.ibm.com (Paul Chamberlain) (09/21/90)

In article <1990Sep20.192923.5119@news.arc.nasa.gov> yee@trident.arc.nasa.gov (Peter E. Yee) writes:
>               Engineers are currently planning a helium signature test on
>          the shuttle's liquid fuel feed lines on Saturday.
>...

I hope they intend to do lots of leak tests _before_ they get
to the deadline.

Paul Chamberlain | I do NOT represent IBM         tif@doorstop, sc30661@ausvm6
512/838-7008     | ...!cs.utexas.edu!ibmaus!auschs!doorstop.austin.ibm.com!tif

n8035388@unicorn.wwu.edu (Worth Henry A) (09/22/90)

In article <3614@awdprime.UUCP> tif@doorstop.austin.ibm.com 
   (Paul Chamberlain) writes:
>In article <1990Sep20.192923.5119@news.arc.nasa.gov> yee@trident.arc.nasa.gov 
    (Peter E. Yee) writes:
>>               Engineers are currently planning a helium signature test on
>>          the shuttle's liquid fuel feed lines on Saturday.
>I hope they intend to do lots of leak tests _before_ they get
>to the deadline.

    Unfortunately, the current leaks were detected after the systems had been
cold-soaked at cryogenic temps. If the helium is not cold enough, the 
physical size of the leaks not large enough, the humidity is not just right,
the lead engineer's biorythm not in sync, ... these and perhaps other leaks 
will not show up until they fill her up with H2 (and perhaps even O2 as 
well), and maybe not even then. And, as someone else has pointed out, if 
they have to go to that much trouble, it might as well be a launch attempt
(they might just get lucky). 

    Of course, a trial run might be worthwhile in the case of missions with 
tight launch windows. But then again, what new problems will be created by 
the thermal (and other) stresses of a trial run? This is hardly non-
destructive testing. 

    Additionally, the shuttles are not being stored in a stasis field
(the unused Saturns are not be the only spacecraft that birds and 
insects are building nests in ;-) ), the longer this goes on and the more 
NASA has to tinker, the worse it is going to get. :-(