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.
MARCH 7, 1986 SESSION (part 2 of
2)
[1206] [Ref. 3/7-76 1 of
2] Failure Scenario 4D.
FAILURE SCENARIO 4D
FAILURE MECHANISM
- PRIMARY O-RING BLOW-BY/LEAKAGE AND O-RING
ACTIVATION DELAYED DUE TO LOW TEMPERATURE
ASSESSMENT METHOD
- LABORATORY TESTS TO FURTHER QUANTIFY
RESILIENCE OF O-RING VERSUS TEMPERATURE
- ANALYSES AND TESTS TO ESTABLISH AMOUNT OF
JOINT ROTATION FOR STS 51-L CONDITIONS INCLUDING EFFECTS OF
PROPELLANT
- DYNAMIC TESTS TO DETERMINE SEALING
CAPABILITY WITH COMBINED EFFECTS OF O-RING PRESSURE ACTUATION,
JOINT ROTATION AND RESILIENCY
FINDINGS TO DATE
- RESILIENCY TESTS SUBSTANTIATE INCREASED
O-RING RESPONSE TIMES AS O-RING TEMPERATURE IS REDUCED
- TESTS SHOW THAT COLD O-RINGS (-10°F)
WILL SEAL WHEN SUBJECTED TO
- MOTOR IGNITION TRANSIENT PRESSURES UNDER
STATIC CONDITIONS
- ANALYSES AND TESTS TO SIMULATE RIGHT HAND
SRM AFT FIELD JOINT DYNAMIC PERFORMANCE UNDER STS 51-L CONDITIONS
ARE REQUIRED
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