yee@trident.arc.nasa.gov (Peter E. Yee) (08/01/90)
Lisa Malone July 31, 1990
(407) 867-2468
KSC Release No. 133-90
MISHAP INVESTIGATION BOARD COMPLETES REPORT ON IMPROPER RAISING
OF DISCOVERY'S PAYLOAD BAY DOOR
Movement of an overhead access bridge while connected to a
payload bay door was the primary cause cited by an investigation
board for the improper raising of a payload bay door on the Space
Shuttle Orbiter Discovery on June 4, 1990. Contributing causes to
the improper raising included failure to follow the approved pro-
cedure, deficient work control systems to preclude bridge move-
ment while connected to a payload bay door, and deficient work
scheduling.
Discovery was located in Orbiter Processing Facility bay 1
undergoing pre-launch preparations for its next mission, STS-
41/Ulysses, when the incident occurred. The aft portion of
Discovery's right hand payload bay door was raised improperly ap-
proximately 31 to 33 inches. The right hand payload bay door
Zero-G system, which is attached to overhead access bridges, was
configured to support a scheduled door closing operation when an
overhead access bridge was moved for another use, causing damage
to support equipment and improper raising of the payload bay
door.
A pulley and wire cable used in the Zero-G system were
damaged in the process. The cost of the mishap, including inspec-
tion of the payload bay door and repair of the support equipment,
was estimated at $120,000.
The board, which was chaired by Paul Myers, technical assis-
tant to KSC's director of Engineering Development, was not
charged with determining any damage to flight hardware. However,
thorough inspections have been performed and it has been deter-
mined that there was no damage to Discovery's payload bay door
from this mishap.
Board members included Hector Delgado, Systems Assurance Of-
fice, Reliability and Quality Assurance Directorate, who served
as deputy chairman; Charles Stevenson, chief, Orbiter Mechanical
Systems Branch, Vehicle Engineering; Tim Yang, facilities systems
engineer, Mechanical and Electrical Systems Branch, Center Sup-
port Operations Directorate; and Laurie Walls, orbiter ground
support equipment and facilities engineer, Structures, Handling
and Access Systems Section, Vehicle Engineering. Elliot Kick-
lighter of the National Space Transportation System Operations
office was the appointed Level II observer. Ex-officio Board mem-
bers included Elizabeth Gruhler, safety advisor; Douglas G.
Hendriksen, legal advisor and Lisa Malone, public affairs ad-
visor.
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Editor's Note: A copy of the board's report is available for
review in the newsroom at the Kennedy Space Center.