[Dick Linn]

From Wikipedia on Duct Tape:

NASA engineers' faith in duct tape as an emergency tool was rewarded in 1970, when the square carbon dioxide filters from Apollo 13's failed command module had to be modified to fit round receptacles in the lunar module, which was being used as a lifeboat after an explosion en route to the moon. Engineers designed a workaround using duct tape and other items on board Apollo 13, relaying directions to the spacecraft's crew. The lunar module CO2 scrubbers started working again, saving the lives of the three astronauts onboard.

Ed Smylie, one of the NASA mission control engineers who designed the scrubber modification in just two days, said later that he knew the problem was solvable when it was confirmed that duct tape was on the spacecraft: "I felt like we were home free" he said in 2005. "One thing a Southern boy will never say is 'I don't think duct tape will fix it'."