CAPE CANAVERAL, Fla. -- NASA has again delayed shuttle Endeavour's nextopportunity to launch, this time to Wednesday, June 5.
NASA managers made that decision during a Sunday meeting to review theprogress made in replacing a faulty part inside one of the shuttle's twoorbital maneuvering engines.
The original repair schedule called for technicians to replace the partby late Saturday and complete tests of the newly installed part by Sunday;however, the unique nature of the repair work and the requirements to testthe new component in Endeavour's rear engine compartment forced NASA to slipthe next launch attempt out to Wednesday.
Liftoff of the 12-day mission to the International Space Station isscheduled between 4 and 8 p.m. EDT (2000 and 2400 GMT) Wednesday. An exactlaunch window will be announced about 5 p.m. EDT (2100 GMT) Tuesday, saidKennedy Space Center spokesman Bruce Buckingham.
The weather outlook for Wednesday is slightly more optimistic than seenduring the past few days, but still indicates the chance of afternoon andevening thunderstorms and rain showers during the launch period.
The part in question is a regulator that controls the pressure of gaseousnitrogen in the left hand Orbital Maneuvering System engine, which is usedafter launch to circularize the shuttle's orbit, make changes to the orbitduring the mission and to brake the shuttle so it falls out of orbit forlanding.The regulator momentarily failed during Endeavour's launch attempt onThursday, but after passing some last minute tests was considered safe tofly.
Then during additional tests of the regulator on Friday, engineers sawthe same problem crop up again and the decision was made to replace thefaulty hardware, said KSC spokesman Bill Johnson.
The regulator is key to safely operating the maneuvering engines becauseit helps manage the inert gas used to open valves which control the amountof propellant flowing into the engines.
The seven-member team making up the STS-111 and Expedition Five flightcrews will remain in Florida to wait out the delay in their mission. Theywill continue to enjoy a light schedule, study their flight plans andparticipate in some training.
Endeavour originally was set for launch Thursday but bad weather scrubbedthe attempt.
The stormy weather persisted into Friday, prompting officials to call offa second attempt even before it started.
With a gloomy forecast for the next few days, mission managers decided tostand down for the weekend to top off some of Endeavour's onboard supplytanks and shoot for a Monday launch attempt.
This technical problem bumped the shot at least another 48 hours.
Managers will meet again Tuesday to assess their readiness for aWednesday launch attempt.
advertisement
