Plot

US Space mission culminates in Apollo 11 mission with Neil Armstrong walking on the moon. It's July 20, 1969. Astronaut Jim Lovell (Tom Hanks) is having a party at his house to celebrate the Apollo 11 Moon landing. Astronaut Jack Swigert (Kevin Bacon) is Jim's colleague & a smart mouth. Astronauts Ken Mattingly (Gary Sinise) and Fred Haise (Bill Paxton) are scheduled to fly on Apollo 14 with Lovell. The space program is under budget constraints once the US citizens realize that they have beaten the Russians to the moon.

But then the primary Apollo 13 crew is sidelined when Allen Shepard develops an ear infection. Jim & his crew are moved up 6 months & will fly Apollo 13. Three months before the launch, Lovell, Haise and Mattingly spend time in the simulator and practice docking with the lunar excursion module (LEM). The technicians shut down some of the Thrusters without warning to see how Mattingly would handle this during an actual flight. Mattingly is caught off guard for a moment, but he manages to complete the procedure successfully.

Marilyn, Jim's wife is suspect of the unlucky # 13, but Jim shrugs her off. He is too determined to walk on the moon. Its his childhood dream. Two days before the launch, Lovell is approached by Deke Slayton and the Flight Surgeon (Christian Clemenson) who tell him that backup crew member Charlie Duke has been diagnosed with measles; this means all the astronauts have been exposed. Lovell says he's had the measles. Slayton says, "Ken Mattingly hasn't.". Flight surgeon predicts that Mattingly will get sick in flight & Jim's choice is to fly without Mattingly (with Swigert) or not at all. Jim decides to take his shot at the moon.

When Mattingly finds out he is upset. He is sure he is not going to fall sick. Swigert enters flight simulations and can't get the re-entry right. The crew synchronization is all shot up. April 11th is launch day & Swigert is very nervous. At Mission Control in Houston, lead Flight Director Gene Kranz (Ed Harris) also gets suited up for the mission. As the leader of the White Team, it's a NASA tradition for him to wear a white vest with the mission insignia. Kranz goes through the Pre-flight checks and launch readiness as the astronauts are strapped into the Command Module Odyssey. Apollo 13 lifts off on time at 1:13 as the crowd applauds. Mid-flight, engine 5 develops a snag and Jim consider the abort button, but then gets the go ahead from Mission Control to continue. Jim thinks that the mission snag.

Swigert then performs a complicated maneuver to dock the service module to the lunar module & does do flawlessly. Jim doesn't have a lot of faith in him. After a routine mid-flight broadcast, CapCom gives Swigert some "housekeeping procedures" to do, including stirring the oxygen tanks. Swigert does so. There's an explosion in an oxygen tank. The spacecraft is violently shaken. Several alarms go off. Lovell asks what he did. He says he just stirred the tanks. In Mission Control, EECOM and Guidance are surprised when their computer screens flicker. CapCom exchanges a confused look with Kranz and says, "This is Houston, say again please?" Lovell says, "Houston, we have a problem."

The explosion has caused the oxygen tanks to suddenly empty. Tank 2 is gone & Tank 1 supply is falling rapidly. It's a quadruple failure with fuel cells 1 and 3 failing as well. Jim looks out the window and can see oxygen spewing out of the tanks. In Mission Control Kranz is stunned & calls each team to call in their support crews. He knows it will be a tough task to bring the crew home with no oxygen. At this point Kranz receives recommendations to shut down the errant fuel cells to isolate the fuel leakage. Cells shut down cannot be revived & module can't land with one fuel cell. This effectively means no Moon landing on this mission.

The leak is in the command module, so Jim orders the Lunar Module to be powered up. CM is down to 15 mins of O2. The CM will be powered down & if the flight guidance data is not transferred to LM before the power down, Apollo 13 will effectively be flying blind & will be lost. Working swiftly, LM is powered up & guidance data transferred in time. LM was not designed to fly with the CM on its back.

Kranz holds a staff meeting to discuss options to bring the module home. The CM engine is considered out of action. CM will only be used for re-entry (although no one knows if the shield is intact). The LM engine will thrust the craft slingshot around the moon and head home. The only issue is that O2 runs out at the halfway mark.

At this point Mattingly is informed about the disaster on Apollo 13 & he heads to Mission Control to help out. His job is to figure out how to power up the CM with 8 amps of power. Kranz uses the rest of the team to design a air filter with only material that Apollo 13 has in the spacecraft. Meanwhile LM has limited power, so everything is shut down the radars, cabin heater, instrument displays, guidance computer, the whole smash.

Swigert thinks the CM is coming in towards Earth too fast & will skip right off. He thinks Mission Control is not telling them this. Jim agrees but says that's a problem for the future. In the face of death, the astronauts have a heated argument, with Haise practically blaming Swigert for all their troubles. Meanwhile the CO2 levels inside the modules keep rising. The engineers at mission control finish the filter & relay the instructions to Jim. The Astronauts build the filter & immediately the Co2 levels start to go down. At least they won't die because of lack of air. Mattingly is still in the simulator trying to figure out the power-up procedure. He uses too much power and has to start over.

Haise falls sick in the CM & has 104 fever. The CM is freezing cold. Kranz receives news that the spacecraft trajectory is too shallow & a course correction is required, but CM cannot be powered up yet. So, it's a blind burn. Jim figures out that they can use the Earth as a reference and steer the engines manually. Mattingly describes the sequence he wants to use for re-entry. Aaron says they don't have enough power, and they have to trade off some of the systems. Mattingly says they need all the systems he's mentioned. They argue about it, and Mattingly says he'll find more power. Jim begs Mission Control to get the procedure up to them because they "can't throw things together at the last minute." He says, "We're all a little tired up here. The world's getting awfully big in the window." Mattingly says that since the LEM draws back-up power from the CM, they should reverse the flow to get more power to the CM. There's no procedure for this, but Young and Aaron agree to try.

Mattingly and Aaron work out the procedure and rush to flight deck to relay the same to Jim. Swigert looks at the condensation on the instrument panels and worries about them shorting out. He says, "It's like trying to drive a toaster through a car wash." Swigert successfully powers up the CM. He says, "We got her back up, Ken. Boy, I wish you were here to see it." Mattingly says, "I'll bet you do." Haise says, "Way to go, Jack." Swigert smiles. The crew jettisons the Service Module, getting their first look at just how much damage the explosion caused. Lovell exclaims, "One whole side of the spacecraft is missing!" He reports that a panel is blown out right up to the heat-shield.

A news anchor on TV says that the heat builds up to 4,000 degrees Fahrenheit on a lunar re-entry flight. "If the heat-shield is even slightly cracked, the extreme cold could have split it wide open. Worst of all, if the pyrotechnics that control the parachutes have been damaged, the chutes may not open at all, causing the spacecraft to hit the water not at a gentle 20 miles per hour, but at a suicidal 300." The team moves from the LM to the CM. They jettison the LEM; Lovell stares after it. Haise swallows hard and says, "She sure was a good ship." Mattingly says, "Farewell, Aquarius, and we thank you." The crew of the aircraft carrier USS Iwo Jima is shown getting ready for the recovery operations.

The Mission Control room is extremely crowded with people waiting for the re-entry. RETRO tells Kranz the trajectory is still slightly shallow and asks if they should tell the crew. Kranz asks if there's anything they can do about it. RETRO says not now. Kranz says, "Then they don't need to know, do they?" It's almost time for entry interface. Lovell says, "Gentlemen, it's been a privilege flying with you." The CM flies toward Earth in a fiery cloud.

Mattingly keeps trying to talk to the crew. INCO says it's been three and a half minutes, then four. Everyone else is quiet and solemn. Then they see the CM on the screen. The parachutes have deployed successfully. The next second, they hear Lovell say, "Hello, Houston? This is Odyssey. It's good to see you again." There's loud applause in Mission Control. After splashdown, Lovell shakes hands with Haise and Swigert. Before a Navy diver comes to retrieve them from the CM, he says, "Houston, we're at stable one, the ship is secure. This is Apollo 13, signing off." Kranz exclaims, "Good job!" in a choked voice and gives a thumbs-up with both hands. Other people in the room continue to applaud.

In the following months, it was determined that a damaged coil built inside the oxygen tank sparked during our Cryo stir and caused the explosion that crippled the Odyssey. It was a minor defect that occurred two years before