Space Shuttle Shuttle orbiter fleet. Sources: NASA launch manifest, NASA Space Shuttle archive On January 28, 1986, "Challenger" disintegrated 73 seconds after launch due to the failure of the right SRB, killing all seven astronauts on board. The disaster was caused by low-temperature impairment of an O-ring, a mission critical seal used between segments of the SRB casing. Failure of the O-ring allowed hot combustion gases to escape from between the booster sections and burn through the adjacent external tank, causing it to explode. Repeated warnings from design engineers voicing concerns about the lack of evidence of the O-rings' safety when the
Space Shuttle Independence Space Center outside Houston, Texas. The replica shuttle was stripped of the name "Explorer" as part of the dismantling process. Upon arriving in the Houston area by barge on June 1, 2012, the shuttle was taken to the Johnson Space Center dock on Clear Lake, and preparations were made to move the shuttle to Space Center Houston during the early morning hours. As with Florida, several light poles along NASA Parkway were taken down and trees trimmed back to allow passage. The shuttle was moved by another 144-wheel trailer down the closed highway to the visitor center. Johnson Space Center