Report of the PRESIDENTIAL COMMISSION
on the Space Shuttle Challenger Accident
Volume 4 Index
Hearings of the Presidential
Commission on the Space Shuttle Challenger Accident: February 6, 1986
to February 25, 1986
FEBRUARY 13, 1986 SESSION. [Part 2 of
2]
[543] [Ref 2/13-38] 51-L FAILURE ANALYSIS STATUS
REPORT
FAILURE SCENARIO (A) - EXTERNAL TANK HYDROGEN LEAK (FIRST EVENT)
EVENT (A2) - LH2 COOLS RIGHT HAND SRM AFT FIELD JOINT
- 51-L OBSERVATIONS/DATA
(A2.1) DOES NOT EXPLAIN ANOMALOUS "SMOKE" AT (OR NEAR LIFT OFF)
- ANALYSES/DATA
(A2.2) 4 LB/SECOND LEAK (0.81" HOLE) WOULD NOT BE DETECTABLE BY
TANK ULLAGE PRESSURE MEASUREMENTS
(A1.3) STRUCTURAL INTEGRITY OF LH2 TANK IS
MAINTAINED WITH A HOLE >0.81" DIAMETER
(A1.4) FILM ENHANCEMENT FOR H2 LEAKING/FLOW
[543] [Ref 2/13-39] 51-L FAILURE
ANALYSIS STATUS REPORT
FAILURE SCENARIO (A) - EXTERNAL TANK HYDROGEN LEAK (FIRST EVENT)
EVENT (A4) -JOINT OVERCOOLED AND O-RINGS FAIL
- 51-L OBSERVATIONS/DATA
(A4.1) SRM HOT GAS BLOWING LEAK EVIDENT AT RIGHT HAND AFT FIELD
JOINTS (58.315 SECONDS)
(A4.2) RIGHT HAND SRM Pc STARTS DIVERGING (59.000
SECONDS)
(A4.3) SRB AND SSME THRUST VECTOR CONTROL EXCURSIONS (61 -
63 SECONDS)
- ANALYSES/DATA
(A4.4) COOLING RATE/TEMPERATURE AT JOINT BY 58.315 SECONDS
(A4.5) CORRELATION OF JOINT LEAK WITH TVC EXCURSIONS
- TESTS
(A4.6) O-RING "FAILURE" AT LOW TEMPERATURE
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