yee@trident.arc.nasa.gov (Peter E. Yee) (06/30/90)
Mark Hess
Headquarters, Washington, D.C. June 29, 1990
(Phone: 202/453-4164) 5:45 p.m. EDT
Ed Campion
Headquarters, Washington, D.C.
(Phone: 202/453-8536)
Lisa Malone
Kennedy Space Center, Fla.
(Phone: 407/867-2468)
RELEASE: 90-89
HYDROGEN LEAK DISCOVERED ON SHUTTLE ATLANTIS
A propellant loading test of the STS-38 Space Shuttle
vehicle, slated to conduct a dedicated Department of Defense
mission in mid-July, revealed a hydrogen leak. Although similar
to the leak that caused the postponement of the STS-35/Astro-1
mission, the leak appears to be smaller than the one detected
during the tanking exercise on the STS-35 vehicle prior to its
rollback to the VAB and demating.
Engineers today loaded the Shuttle's external fuel tank to
about the 5 percent level to check for leaks in the umbilical
between the orbiter Atlantis and the fuel tank. Instrumentation
located in the umbilical area detected hydrogen shortly after the
fueling process went from a slow fill to a fast fill mode.
Engineers believe the leak is in a cavity between the
orbiter and external tank umbilical plates. While the leak's
precise location is not known, tests today indicate the 17" line
between the orbiter and the ET used to feed hydrogen to the
orbiter's three main engines is contributing to the leak. The
leak appears to be both temperature and flow-rate dependent.
Columbia is currently in the Orbiter Processing Facility
(OPF). Its umbilical has been removed and is scheduled to be
shipped to Rockwell-Downey this weekend for installation in a
test stand for further leak testing. Tests of the ET side of the
STS-35 umbilical did not reveal any leaks large enough to account
for the leak seen during tanking of the STS-35 vehicle.
Leonard Nicholson, Deputy Director, Space Shuttle Program,
will lead the NASA/industry team charged with analyzing the cause
of the leak and determining corrective actions.
Until the cause of the leak has been determined, further
processing of the STS-38 vehicle has been suspended. When the
problem has been identified it is expected that STS-38 will be
brought back to the VAB and the orbiter demated from the tank to
make the necessary repairs. While a new target date is not known
for the STS-38 launch, it is expected the flight will be delayed
a minimum of two weeks.
Briefings to the news media updating the progress on the
investigations are tentatively planned for Tuesday, July 3 and
Friday, July 6 from NASA Headquarters, Washington, D.C.n8035388@unicorn.WWU.EDU (Worth Henry A) (06/30/90)
In article <52769@ames.arc.nasa.gov> yee@trident.arc.nasa.gov (Peter E. Yee) writes: > >HYDROGEN LEAK DISCOVERED ON SHUTTLE ATLANTIS > > > A propellant loading test of the STS-38 Space Shuttle >vehicle, slated to conduct a dedicated Department of Defense >mission in mid-July, revealed a hydrogen leak. Although similar >to the leak that caused the postponement of the STS-35/Astro-1 >mission, the leak appears to be smaller than the one detected >during the tanking exercise on the STS-35 vehicle prior to its >rollback to the VAB and demating. > Ok, I haven't seen anyone else asking, so I'll bite... Are these leaks REALLY something NEW or has NASA installed some new leak sensors that are detecting leaks that have existed all along? Perhaps some other change in the monitoring system or procedures? After all, in practice, monitoring systems are often more prone to problems than the systems they are suppose to monitor (need I mention HUBBLE? :-) ). Perhaps a decimal point was substituted for a comma in a DO statement of the latest version of the FORTRAN program that monitors the sensors? :-) HW 6/29/90