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)
[1208] [Ref. 3/7-77 1 of
3] Failure Scenario 5.
FAILURE SCENARIO 5
FAILURE MECHANISM
- INDUCED LIFTOFF OR FLIGHT LOADS DAMAGED
JOINT:OR PRODUCED EXCESSIVE JOINT ROTATION RESULTING IN
FAILURE
ASSESSMENT METHOD
- DETERMINE LOADS EXPERIENCED BY STS 51-L
FOR ALL FLIGHT EVENTS
- COMPARE STS 51-L LOADS WITH DESIGN
CONDITIONS
- CONDUCT SPECIAL JOINT DYNAMIC ANALYSIS TO
EVALUATE INDUCED LOADS
FINDINGS TO DATE
- STS 51-L INDUCED LIFTOFF LOADS ARE LESS
THAN DESIGN LOADS BASED ON:
- CAMERA OBSERVATIONS OF TWANG
MOVEMENT
- HOLDDOWN POST STRAIN GAUGE DATA
- RECONSTRUCTED LOADS BASED ON THRUST
BUILDUP, WINDS, THRUST MISMATCHES AND VEHICLE DYNAMIC
MODEL
[1209] [Ref. 3/7-77 2 of
3] Failure Scenario 5 (continued).
FAILURE SCENARIOS 5 (CONT'D)
- LIFT-OFF AND MAX "Q" LOADS WERE WITHIN
DESIGN LOADS
- AN OVERLOAD ON STRUCTURE DID NOT
OCCUR
- ANALYSIS CONTINUING TO DETERMINE EFFECT OF
ACTUAL MAX "Q" LOADS ON GAP OPENING WITH POTENTIAL OF DEGRADED
SEAL
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