CAPE CANAVERAL, Fla. – United Space Alliance technicians remove and replace all the hub tiles on space shuttle Discovery before its STS-119 mission targeted for Feb. 12. Hub tiles, heat protection tiles, are difficult to install because of their location on the inboard side of the inboard elevons. On the STS-119 mission, Discovery will carry the S6 truss segment to complete the 361-foot-long backbone of the International Space Station. The truss includes the fourth pair of solar array wings and electronics that convert sunlight to power for the orbiting laboratory. Photo credit: NASA/Dimitri Gerondidakis

CAPE CANAVERAL, Fla. – United Space Alliance technicians remove and replace all the hub tiles on space shuttle Discovery before its STS-119 mission targeted for Feb. 12. Hub tiles, heat protection tiles, are difficult to install because of their location on the inboard side of the inboard elevons. On the STS-119 mission, Discovery will carry the S6 truss segment to complete the 361-foot-long backbone of the International Space Station. The truss includes the fourth pair of solar array wings and electronics that convert sunlight to power for the orbiting laboratory. Photo credit: NASA/Dimitri Gerondidakis

CAPE CANAVERAL, Fla. – United Space Alliance technicians remove and replace all the hub tiles on space shuttle Discovery before its STS-119 mission targeted for Feb. 12. Hub tiles, heat protection tiles, are difficult to install because of their location on the inboard side of the inboard elevons. On the STS-119 mission, Discovery will carry the S6 truss segment to complete the 361-foot-long backbone of the International Space Station. The truss includes the fourth pair of solar array wings and electronics that convert sunlight to power for the orbiting laboratory. Photo credit: NASA/Dimitri Gerondidakis

CAPE CANAVERAL, Fla. – United Space Alliance technicians remove and replace all the hub tiles on space shuttle Discovery before its STS-119 mission targeted for Feb. 12. Hub tiles, heat protection tiles, are difficult to install because of their location on the inboard side of the inboard elevons. On the STS-119 mission, Discovery will carry the S6 truss segment to complete the 361-foot-long backbone of the International Space Station. The truss includes the fourth pair of solar array wings and electronics that convert sunlight to power for the orbiting laboratory. Photo credit: NASA/Dimitri Gerondidakis

CAPE CANAVERAL, Fla. – United Space Alliance technicians remove and replace all the hub tiles on space shuttle Discovery before its STS-119 mission targeted for Feb. 12. Hub tiles, heat protection tiles, are difficult to install because of their location on the inboard side of the inboard elevons. On the STS-119 mission, Discovery will carry the S6 truss segment to complete the 361-foot-long backbone of the International Space Station. The truss includes the fourth pair of solar array wings and electronics that convert sunlight to power for the orbiting laboratory. Photo credit: NASA/Dimitri Gerondidakis

CAPE CANAVERAL, Fla. – A closeup of hub tiles replaced on space shuttle Discovery before its STS-119 mission targeted for Feb. 12. Hub tiles, heat protection tiles, are difficult to install because of their location on the inboard side of the inboard elevons. On the STS-119 mission, Discovery will carry the S6 truss segment to complete the 361-foot-long backbone of the International Space Station. The truss includes the fourth pair of solar array wings and electronics that convert sunlight to power for the orbiting laboratory. Photo credit: NASA/Dimitri Gerondidakis