Report of the PRESIDENTIAL COMMISSION
on the Space Shuttle Challenger Accident
Volume 5 Index
Hearings of the Presidential
Commission on the Space Shuttle Challenger Accident: February 26,
1986 to May 2, 1986.
FEBRUARY 26, 1986 SESSION (part 1 of
2)
[908] [Ref. 2/26-5]
General Conclusions.
General Conclusions
- All O-ring erosion has occurred where gas
paths In the vacuum putty are formed
- Gas paths in the vacuum putty can occur
during assembly, leak check, or during motor pressurization
- Improved filler materials or layup
configurations which still allow a valid leak check of the primary
O-rings may reduce frequency of O-ring erosion but will probably
not eliminate it or reduce the severity of erosion
- Elimination of vacuum putty in a tighter
joint area will eliminate O-ring erosion if circumferential flow
is not present - if it Is present, some baffle arrangement may be
required
- Erosion in the nozzle joint is more severe
due to eccentricity; however, the secondary seal in the nozzle
will seal and will not erode through
- The primary O-ring in the field joint
should not erode through but if it leaks due to erosion or lack of
sealing the secondary seal may not seal the motor. Data obtained on resiliency of the O-rings indicate
that lower temperature aggravate this problem
- The igniter Gask-O-Seal design Is adequate
providing proper quality inspections are made to eliminate
overfill conditions
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