What began as a routine third lunar landing attempt to the Fra Mauro region became one of the most gripping episodes in the history of spaceflight. At 9:08 p.m. CST on April 13, 1970, some 205,000 miles from Earth, the crew — Commander James A. Lovell Jr., Lunar Module Pilot Fred W. Haise Jr., and Command Module Pilot John L. "Jack" Swigert — heard a sharp bang. An oxygen tank in the Service Module had exploded. Swigert radioed: "Houston, we’ve had a problem here." The blast crippled the Command Module Odyssey, venting the spacecraft’s oxygen and electrical power into space. With the lunar landing aborted, Mission Control and the crew improvised a survival plan: the Lunar Module Aquarius became a lifeboat, its descent engine used to steer the spacecraft around the Moon and back toward Earth. The crew endured freezing temperatures, minimal power, and a critical carbon-dioxide buildup that engineers on the ground solved by jury-rigging square Command Module canisters to fit the Lunar Module’s round openings — literally fitting a square peg in a round hole. After a harrowing six days, the crew jettisoned Aquarius, powered up Odyssey in the final hours, and splashed down safely in the Pacific on April 17. The mission was a "successful failure": it never landed, but it proved NASA’s ingenuity under extreme pressure and led to safety improvements that benefited the remaining Apollo flights.