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Conference 7.286::space

Title:Space Exploration
Notice:Shuttle launch schedules, see Note 6
Moderator:PRAGMA::GRIFFIN
Created:Mon Feb 17 1986
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:974
Total number of notes:18843

393.0. "Shuttle Manufacturing Flaws?" by MILVAX::SCOLARO () Tue Jan 26 1988 13:38

    This morning (1/26/88), NPR quoted the Washington Post as saying
    there were flaws in shuttle manufacturing, not design.  These flaws
    were not spelled out and I was wondering if anyone knew what they
    were and how serious a threat they pose to a launch this year.
    
    Tony
T.RTitleUserPersonal
Name		DateLines
393.1MONSTR::HUGHESTue Jan 26 1988 17:154
    The comments I heard were around the SRB (I think to do with the
    last static test failure) and some flaws in one or more of the SSMEs.
    
    gary
393.2in the orbiter...SHAOLN::DENSMORELegion of Decency, RetiredWed Jan 27 1988 07:408
    I heard that there were flaws in the main engines, specifically
    in the turbines.  (Hmmm, haven't I heard that somewhere else?) 
    I believe that they must now replace the units in all three orbiters.
    And, yes, it is apparently an manufacturing problem.
    
    Any more details available?
    
    						Mike
393.3Ultra Sonic Welding Checker Pays OffIMGAWN::BIROWed Jan 27 1988 08:5719
    The problems reported today on NPR (27 wen JAN 88) were for
    two faulty welds
    
    1st) a crack in the weld of a pump motor, this is a serious problem
         but a replacement one can be installed without any change in
         the Shuttle Schedule.  This is a serious problem and has to
         be corrected.
    
    2nd) a 3/4 inch crack in the skirt around then eng, this skirt is
         used to hold the rocket down.  This may be a don't care but
         it will have to be evaluated first.
     
    I was interested and glad  that these welding faults were detected 
    by a new ultrasonic detector.  This is one of the new safety
    measures that have been added and is paying off.  The reporter
    went on to say that it was unknown if previous shuttles had these
    problems or not as this ultrasonic detector was not in use then.
393.4ASS-U-ME (assume)RANGLY::BARNABY_GALESun Feb 21 1988 21:063
    I new they used ultrasonics on blades in the windtunnel and checking
    models run in windtunnels, I ASSUMED they would check something
    as important as a shuttle.
393.5Replacing 72 bolts on the SRB nozzlesDICKNS::KLAESThrough the land of Mercia...Thu Mar 10 1988 15:5636
From: [email protected] (markf)
Newsgroups: sci.space
Subject: NASA News Release
Date: 8 Mar 88 00:33:29 GMT
Organization: Alpha Comm. Dev. Corp., Aurora, Colo.
  
    NASA NEWS - NASA Examines 72 Nozzle Bolts
 
    NASA and Morton Thiokol are examining 72 bolts in the interior of
the Space Shuttle solid rocket motor nozzle. The bolts, which measure
3/4" by 2 1/2", attatch the nozzle fixed housing to the nozzle's flex
bearing assembly. 
 
    Replacement is being considered because the bolts are threaded all
the way to the bolt head instead of having a smooth bolt shank. A
smooth shank may be preferred to assure that special Stat-O-Seal
washers located under the bolt heads seal properly. The washers form a
secondary seal intended to prevent gas leakage past the attachment
bolts should there be a leak past the primary o-ring seal in this
joint. The washers were added as part of the overall SRM redesign for
additional seal redundancy, even though the previous single seal
design has never experienced any difficult or distress in any previous
ground test or flight motor firing. 
 
    Preliminary tests at the equivalent of full motor pressure have
shown no external leakage with the current bolts. As a precaution,
however, further special tests and analyses are being conducted to
determine if replacement of the bolts and seals is necessary. 
 
-----------------------------------------------------------
NASA News Release 88-18 - Reprinted with permission for 
electronic distribution -
Article by Sarah Keegan, Headquaters, Washington, D.C.
and Ed Medal, Marshall Space Flight Center, Huntsville, Ala.
Feb 9, 1988