On July 20, 1969, astronaut Jim Lovell watches with family and friends as Neil Armstrong’s first steps on the Moon are televised. Lovell, who took part in the National Aeronautics and Space Administration’s (NASA) Moon-orbiting Apollo 8 mission the previous year, vows to complete a moonwalk, himself. He is initially scheduled to take part in the Apollo 14 mission; however, he and his crew, including Ken Mattingly and Fred Haise, are called on to replace Alan Shepard’s team for the upcoming Apollo 13 mission. When Mattingly is exposed to German Measles, Jack Swigert must take his place. Lovell frets over losing Mattingly but agrees to move forward. On April 11, 1970, the Saturn V rocket launches the Apollo 13 spacecraft out of the Earth’s atmosphere. Three days later, the crew films a television transmission from inside the command module Odyssey. Shortly after, a liquid oxygen tank explodes when Swigert turns it on, and its contents are lost. The crew discover that another oxygen tank is leaking, which requires two fuel cells to be shut off. In the face of these technical difficulties, the Moon landing must be aborted. The lunar module Aquarius is used to power an emergency return to Earth. Meanwhile, at a command station in Houston, Texas, NASA flight director Gene Kranz works with his team to bring the men home safely. Tensions rise among Lovell and his team, as the command module’s cabin loses heat due to power restrictions. Haise suffers a urinary tract infection which leads to fever. He argues with Swigert, whom he blames for the oxygen tank malfunction, but Lovell steps in to mediate. With carbon dioxide levels spiking inside the cabin, Kranz’s team in Houston works frantically to save the astronauts. They engineer a way for Lovell’s team to release the damaged Aquarius module just before re-entry to the Earth’s atmosphere via the Odyssey. Ground control loses communication with the Apollo 13 team longer than expected, but they land safely in the Pacific Ocean. They are rescued and brought aboard the U.S.S. Iwojima, where they are received as heroes. As an older man, Lovell recalls that, following an investigation, it was determined that a minor defect caused the oxygen tank explosion. Apollo 13 marked the final mission into space for his team. Mattingly, who never contracted Measles, orbited the Moon via the Apollo 16 mission in 1972. Ten years later, Swigert was elected to Congress but died of cancer before he could take office. Lovell continued to follow NASA’s work, and watched other astronauts fulfill his dream of walking on the Moon.