Why did Apollo 13 go to the moon?

Answer 1

Apollo 13 crew did NOT go to the moon. The third lunar landing attempt was aborted after the rupture of service module oxygen tank. Classified as "successful failure" because the crew was not lost . Spent upper stage successfully impacted on the Moon thus part of Apollo 13 did land on the moon.

Apollo 13 was supposed to land in the Fra Mauro area. An explosion on board forced Apollo 13 to circle the moon without landing. The Fra Mauro site was reassigned to Apollo 14.

The crew of Apollo 13 was James A. Lovell, Jr. , John L. Swigert, Jr. and Fred W. Haise, Jr. Ken Mattingly was on the original crew as the Command Module Pilot but was replaced by Swigert once it was learned that he had been accidently exposed to the infectious disease measles, which he had no immunity to as the other two crew members did.

Apollo 13 story in brief: After a conference with contractor and NASA personnel, the test director decided to "boil off" the remaining oxygen in No. 2, which had been previously installed in the service module of Apollo 10, by using the electrical heater within the tank. The technique worked. Due to an oversight in replacing an underrated component during a design modification, this turned out to severely damage the internal heating elements of the tank. Nine minutes after saying "good-night" in an untelevised "open house" from the spacecreaft oxygen tank No. 2 blew up, causing No. 1 tank also to fail. The Apollo 13 command modules normal supply of electricity, light, and water was lost, and they were about 200,000 miles from Earth. Warning lights indicated that one oxygen tank appeared to be completely empty, and that the oxygen in the second tank was rapidly being depleted. It was after the blackout period that Swigert reported, "Houston, we've had a problem here." Thirteen minutes after the explosion, Lovell looked out the window of the spacecreft on the left-hand side and noticed the very important vapor escaping into the atmosphere. "We are venting something out into the- into space," he reported to Houston. Lovell said, "It's a gas of some sort." It was oxygen gas escaping at a high rate from the second, and last, oxygen tank. At 1 hour and 29 seconds after the bang, Jack Lousma, then CapCom, said after instructions from Flight Director Glynn Lunney: "It is slowly going to zero, and we are starting to think about the LM lifeboat." Swigert replied, "That's what we have been thinking about too." So the crew, with great mathematical skills brought up the computers and life support of the LM. With only 15 minutes of power left in the CM, CapCom told the crew to make their way into the LM. Fred and Jim Lovell quickly floated through the tunnel, leaving Jack to perform the last chores in the CM. The first concern was to determine if there were enough consumables to get home. Oxygen wasn't the main problem, power was. As Gene Kranz told his sleep-deprived staff, "Failure is NOT an option". Ground controllers, specifically John Aaron, carefully worked out a procedure where the CM batteries were charged with LM power. All non-critical systems were turned off and energy consumption was reduced to a fifth of normal, which resulted in having 20 percent of our LM electrical power left when Aquarius was jettisoned. Removal of Carbon Dioxide was also a concern. There were enough lithium hydroxide canisters, which remove carbon dioxide from the spacecraft, but the square canisters from the CM were not compatible with the round openings in the LM environmental system. After a day and a half in the LM a warning light showed that the carbon dioxide had built up to a dangerous level. Mission Control devised a way to attach the CM canisters to the LM system by using plastic bags, cardboard, and tape- all materials carried on board. One of the big questions was, "How to get back safely to Earth?" The LM navigation system wasn't designed to help us in this situation. A most remarkable achievement of Mission Control was quickly developing procedures for powering up the CM after its long cold sleep. Flight controllers wrote the documents for this innovation in three days, instead of the usual three months. Four hours before slashdown, the crew shed the service module which had been kept in hopes of protecting the heat shields. The crew left the Lunar Module Aquarius and then splashed down gently in the Pacific Ocean near Samoa. After an intensive investigation, the Apollo 13 Accident Review Board identified the cause of the explosion. In 1965 the CM had undergone many improvements, which included raising the permissible voltage to the heaters in the oxygen tanks from 28 to 65 volts DC. Unfortunately, the thermostatic switches on these heaters weren't modified to suit the change. During one final test on the launch pad, the heaters were on for a long period of time. "This subjected the wiring in the vicinity of the heaters to very high temperatures (1000 F), which have been subsequently shown to severely degrade Teflon insulation. The thermostatic switches started to open while powered by 65 volts DC and were probably welded shut." Furthermore, other warning signs during testing went unheeded and the tank, damaged from 8 hours overheating, was a potential bomb the next time it was filled with oxygen. That bomb exploded on April 13, 1970 -- 200,000 miles from Earth.

-adapted from NASA website and James A. Lovell, Apollo Expeditions to the Moon