Mission summary STS-26

1 mission summary

1.1 payloads , experiments
1.2 list of payloads

1.2.1 primary payload
1.2.2 secondary payloads


1.3 damage thermal protection

mission summary

space shuttle discovery lifted off pad b, launch complex 39, kennedy space center, @ 11:37 am edt on 29 september 1988, 975 days after challenger disaster. launch delayed 1 hour , 38 minutes due unseasonable , unusual light winds, , need replace fuses in cooling systems of 2 crew members flight suits. suits repaired, , waiver issued wind conditions after officials determined there sufficient safety margin wind loads on orbiter s wing leading edges. @ t-1:30, proposed launch delayed @ t-0:31 due cabin air pressure issue. determined cabin pressure had been increased activation of oxygen systems in crew s flight suits, , launch conducted without further delay. shuttle crew, veteran astronauts, included commander frederick h. rick hauck, pilot richard o. covey, , mission specialists john m. mike lounge, george d. pinky nelson , david c. hilmers.

the primary payload sts-26 mission, tracking , data relay satellite (tdrs), deployed, , 11 scheduled mid-deck scientific , technological experiments carried out. orbiter sustained minor thermal protection system tile damage, , redesigned post-challenger solid rocket boosters showed no signs of leakage or overheating @ of joints.

two minor problems occurred during flight. after ascent, flash evaporator system cooling orbiter iced , shut down, increasing crew cabin temperature approximately 87 °f (31 °c). problem resolved on flight day 4 , cooler temperatures resulted. ku-band antenna communications deployed on flight day 2, failed respond , had stowed remainder of mission.

during sts-26, discovery became first spacecraft fly in space equipped vcu (voice control unit), computer capable of recognising , responding human speech. vcu created sci systems in huntsville, alabama, , based on technology licensed votan company. speech recognition system controlled cameras , monitors used crew monitor canadarm mechanical arm mounted in cargo bay. because of experimental nature of speech recognition @ time, system not used critical operations. initial problems sidelined tests when voice templates created prior liftoff found have less 60% recognition 1 crew member , less 40% recognition another. problem corrected retraining templates. retested , found operational recognition success rate of on 96%. concluded weightless conditions caused fundamental change in human speech, making templates created prior liftoff virtually useless.

besides conducting mission s various experiments, crew members practiced suiting in new partial-pressure launch-and-entry flight suits, , practiced unstowing , attaching of new crew escape system. on 2 october, day before mission ended, five-man crew paid tribute 7 crew members lost in challenger disaster.

discovery landed on runway 17, edwards air force base, california, @ 12:37 pm edt on 3 october 1988, after mission duration of approximately 4 days , 1 hour. capsule communicator blaine hammond jr. welcomed crew, saying great ending new beginning.

payloads , experiments

tdrs-3 after deployment.

tdrs-c, became tdrs-3 in orbit, , attached inertial upper stage (ius), deployed discovery s cargo bay 6 hours , 13 minutes flight. first stage of ius placed tdrs-3 in transfer orbit, , second stage placed in geosynchronous orbit on 30 september. tdrs-3 moved position on pacific ocean south of hawaii @ 171 degrees west longitude. joined tdrs-1 in tracking earth-orbiting spacecraft; sister satellite, tdrs-b, lost in challenger accident. in payload bay orbiter experiments autonomous supporting instrumentation system (oasis). oasis recorded environmental data on orbiter , tdrs payload during various inflight phases.

all mission s mid-deck experiments deemed have been performed successfully. however, there glitches 2 of 5 materials science experiments. in protein crystal growth experiment, 2 of 11 proteins processed – including enzyme believed key replication of aids – did not produce crystals suitable analysis. also, there equipment problems automated directional solidification furnace, experiment investigate melting , solidification of various materials in zero-gravity.

the materials processing experiments included 2 shuttle student involvement projects, 1 on titanium grain formation , other on controlling crystal growth membrane. materials science experiment, physical vapor transport of organic solids, joint project of nasa s office of commercial programs , 3m company.

three life sciences experiments conducted, including 1 on aggregration of red blood cells, intended determine if microgravity can play beneficial role in clinical research , medical diagnostic tests. 2 further experiments involved atmospheric sciences, while 1 in communications research.

list of payloads

the tdrs prepared deployment.


primary payload

nasa s tracking , data relay satellite-3 (tdrs-3), attached inertial upper stage (ius), became second tdrs deployed. after deployment, ius propelled satellite geosynchronous orbit.

secondary payloads

physical vapor transport of organic solids (pvtos)
protein crystal growth (pcg)
infrared communications flight experiment (ircfe)
aggregation of red blood cells (arc)
isoelectric focusing experiment (ife)
mesoscale lightning experiment (mle)
phase partitioning experiment (ppe)
earth-limb radiance experiment (elrad)
automated directional solidification furnace (adsf)
two shuttle student involvement program (ssip) experiments
voice control unit test , evaluation (vcu)

damage thermal protection

discovery suffered severe damage thermal protection tiles in underwing area. post-flight analysis showed impact of 12-inch long piece of cork insulation during ascent culprit. origin of debris forward field joint on right-hand srb. damage such that, during re-entry, thermal protection tile eroded completely.