yee@ames.arc.nasa.gov (Peter E. Yee) (07/01/88)
Sarah Keegan
Headquarters, Washington, D.C. July 1, 1988
(Phone: 202/453-8536)
Ed Medal
Marshall Space Flight Center, Huntsville, Ala.
(Phone: 205/544-0034)
RELEASE: 88-86
FINAL SHUTTLE MOTOR JOINT TEST SCHEDULED AT MORTON THIOKOL
Morton Thiokol, NASA's prime contractor for the Space
Shuttle solid rocket motor, will conduct the seventh Joint
Environment Simulator (JES) test Sunday, July 3, 1988, at 3:00
p.m. EDT, at its Space Operations facility in Utah. The test is
part of the Space Shuttle solid rocket motor redesign program and
is the final such test required prior to resumption of Shuttle
flights.
JES tests are short-duration, ignition pressure tests using
full-scale motor hardware to form two field joints. The tests
are used to evaluate the redesigned joints.
This test article, designated JES-3C, will be extensively
flawed, including a wave-type defect in the J-seal bonded
insulation of joint A, plus intentional channel-like defects
through the J-seal in both joints. In addition, the capture
feature O-ring will be flawed in joint A and both the capture
feature and primary O-rings will be flawed in joint B. The
defects are intended to ensure hot gas flow reaches the primary
O-ring in joint A and the secondary O-ring in joint B. This will
allow engineers to verify the performance of the O-ring seals
under hot gas conditions.
The field joints also have both intentional and natural edge
unbonds, some of which have been repaired. The test will allow
engineers to evaluate the effect of existing unbonds and also to
evaluate the effectiveness of unbond repair procedures.
Deliberate flaws also will be introduced in some of the primary
seals in the motor igniter.
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About 385 pounds of live propellant are used in a JES test
to provide hot gas to duplicate the ignition pressure buildup of
a full-size motor. For this test, hot gas and pressure will be
retained inside the test article and not allowed to vent until
about 2 minutes after ignition. This simulates full-duration
motor conditions.
-end-
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