STS-61-C STS-61-C STS-61-C was the twenty-fourth mission of NASA's Space Shuttle program, and the seventh mission of Space Shuttle "Columbia". It was the first time that "Columbia", the first space-rated Space Shuttle orbiter to be constructed, had flown since STS-9. The mission launched from Florida's Kennedy Space Center on 12 January 1986, and landed six days later on 18 January. STS-61-C's seven-person crew included the second African-American shuttle pilot, future NASA Administrator Charles Bolden, the first Costa Rican-born astronaut, Franklin Chang-Diaz, and the second sitting politician to fly in space, Representative Bill Nelson (D-FL). It was the last shuttle mission before
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