ty was 223 feet per second lower than planned. Again, the guidance computer attempted to correct this by causing the third stage, the S4B, to burn it's single engine 9 seconds longer than programmed."Two hours and 35 minutes after launch, the crew fired the S4B a second time for a translunar injection." Once out of Earth orbit, Lovell performed a transposition maneuver. He moved the command module away from the S4B, turned it around, and docked nose first with the lunar module, still encapsulated in the forward section of the S4B. Once the maneuver was complete and the Lunar Module was secured to the Apollo command module, the crew activated springs that pushed the LM-Apollo stack away from the S4B. As the stack moved away from the S4B, controllers at Houston directed it to its predetermined lunar crash site. At this point, all was well and the crew went on as planned.At 9 p.m. on April 13th, Mission Control asked the crew to roll the spacecraft to the right about 60 degrees and try to photograph a comet named Benntt was supposed to be visible. They were also asked to stir the liquid oxygen and liquid hydrogen in the service module tanks in order to ensure proper feed to the fuel cell batteries, in which oxygen and hydrogen were mixed to produce electricity and as a by-product, water.Then suddenly, Haise asked Houston to stand by a moment and then he said: "Hey, we've got a problem here." There had been a main bus B interval, meaning, the amperage on the bus that distributed power to the ship had suddenly surged up and dropped back down.The crew then reported that the main bus A was showing abnormally low voltage. A moment later, it was discovered that liquid oxygen Tank No. 2 supplying the fuel cells power system was reading zero. "We are venting something out into space," Lovell said. "It's a gas of some sort." It was oxygen. The number 2 tank had ruptured. Two of the ships three fuel cell batteries were dead, leavin...
