Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!cs.utexas.edu!wasatch!ch-tkr
From: ch-tkr@wasatch.utah.edu (Timothy K Reynolds)
Newsgroups: sci.space.shuttle
Subject: Re: Shuttle Status for 06/23/89 (Forwarded)
Summary: new version of cryogenic circulation pumps
Message-ID: <2087@wasatch.utah.edu>
Date: 23 Jun 89 18:35:29 GMT
References: <27454@ames.arc.nasa.gov>
Organization: University of Utah CS Dept
Lines: 34

In article <27454@ames.arc.nasa.gov>, yee@trident.arc.nasa.gov (Peter E. Yee) writes:
> 
>              KSC SPACE SHUTTLE PROCESSING REPORT - FRIDAY, JUNE 23, 1989
>                      STS-28  -  COLUMBIA (OV 102)  -  OPF BAY 1
> 
>                Yesterday, technicians replaced the liquid hydrogen
>           recirculation pump package with a new version designed to guard
>           against shorting out. The first launch attempt for the STS-30
>           mission was halted because of an electrical short in one of the
>           recirculation pumps. These pumps, one for each engine, circulate
>           liquid hydrogen through the main engines to condition them prior
>           to start.

It seems to me that this redesign/replacement occured very rapidly (for a
Gov't agency, that is).  It has only been a few months since the shorting
of one of these pumps scrubbed the STS-30 launch.  Did NASA already know about
this problem an have a fix in the works?

It appears to me that this is the only way that such a 'redesign'  could have
happened so quickly.  This is especially true for a man rated system.  I
imagine that the amount of QC and testing would be considerable even though
these pumps are not used during flight (just on the pad to keep things cool).
A catastrophic failure of a recirculating pump on the pad would still cause
lots of havoc.

Does anybody out there have any specifics on these pumps and their new design?
I would like to believe NASA _did_ complete the redesign and certification in
the short time since the launch of STS-30, but I'm skeptical.

ch-tkr @wasatch.utah.edu		c/o Center for Micro-Analysis
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_	    214 EMRL Bldg 61
Remember: if you aren't recycling     |	    University of Utah
you're just throwing it all away.     |	    SLC, Utah   84112
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_     801-581-8431