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Apollo 13 was the third American manned lunar landing mission, part of the Apollo Program . Two days after launch, an explosion caused the Service Module portion of the Apollo Command/Service Module to lose its oxygen and electrical power. The crew used the Lunar Module as a lifeboat in space. The command module systems remained functional but were deactivated to preserve its capability to reenter earth's atmosphere upon return to the earth. The crew endured difficult conditions due to severe constraints on power, cabin heat and drinkable water, but successfully returned to earth. CREW
Backup crew
Support crew
Changes Ken Mattingly , who was slated to be command module pilot, was grounded shortly before launch due to exposure to Rubella , which he was not immune to (and never ended up contracting). He was replaced by John Swigert, for Apollo 13 and he later flew with Young and Duke (Apollo 13 back-up crew) as command module pilot on Apollo 16 . MISSION PARAMETERS
Oxygen tank explosion Closest approach to Moon
See also QUOTE Famous misquote: "''Houston, we have a problem''" Actual quote: "''Okay, Houston, we've had a problem here''" {Link without Title} , uttered by Swigert to ground. Lovell then uttered this similar phrase: "''Houston, we've had a problem.''" MISSION HIGHLIGHTS The Apollo 13 mission began with a lesser known malfunction which could have been equally catastrophic. During second stage burn the center engine shut down prematurely. Engineers later discovered that this was due to dangerous Pogo Oscillation s which might have torn the second stage apart; the engine was experiencing 68g vibrations at 16 hertz, flexing the thrust frame by 3 inches. Luckily the oscillations caused a low pressure reading to register, and the computer shut the engine down automatically. This was later traced to amplification of the pogo that had occurred on previous flights by an unexpected interaction with the cavitation in the turbopumps. Later missions had anti-pogo devices, as had already been planned since before Apollo 13, which solved the problem. Problem As the Spacecraft was on its way to the Moon, at a distance of 321,860 kilometers (199,990 mi) from Earth, the number two oxygen tank in the Service Module (SM) exploded when Mission Control requested that the crew perform a "cryo stir", in which the oxygen "slush" is stirred to prevent it from stratifying. Teflon insulation covering damaged electrical wires powering the stirrer motor caught fire when power was applied. The fire caused a pressure increase above the tank's nominal 1,000 lbf/in² (7 MPa), and the tank exploded. This explosion damaged other parts of the service module, including the number 1 oxygen tank. At the time of the explosion, however, the true cause was not known; one conjecture was a Meteoroid impact. The loss of both oxygen tanks in the service module and thus the oxygen required to create electrical power for the Command/Service Modules (CSM) meant that the CSM had to be completely shut down. The Command Module (CM) contained batteries for use during re-entry, after the Service Module was jettisoned, but these would only last about ten hours, and needed to be saved for re-entry. The crew survived by using the Lunar Module (LM, still attached to the CM) as a "lifeboat". The damage to the CSM meant that the Moon-landing mission (originally intended to land at the Fra Mauro Highlands) had to be aborted; a single pass around the Moon was made and the spacecraft returned to Earth in what is called a modified ''circumlunar'', '''''cislunar''''', or Free Return Trajectory , which goes completely around the moon in a Figure 8 geometry but is not considered a true orbit, as it is fleeting and there is no capture within the moon's gravity well. Considerable ingenuity under extreme pressure was required from both the crew and the Flight Controller s to figure out how to Jury Rig the craft for the crew's safe return, with much of the world watching the drama on television. One of the major stumbling blocks in this was that the LM "lifeboat" was equipped to sustain two people for two days, and it would now have to sustain three people for four days. One of the most critical problems was that the Lithium Hydroxide Carbon Dioxide filters in the LM would not last for all four days, and the CM's spare filters were the wrong shape for the LM's filter receptacle; an adapter had to be fabricated from materials in the spacecraft. To accomplish a safe return to Earth, a significant course correction to place the spacecraft on a Free Return Trajectory was required. This would normally be a simple procedure using the Service Module Propulsion engine. However, the Flight Controller s did not know the extent of the damage the service module had suffered and did not want to risk firing the main engine. Instead, the course correction would have to be performed by firing the lunar module's descent engine. After extensive discussion, engineers on the ground found it was possible. The initial maneuver to change to a free return trajectory was made within hours of the accident. The descent engine was fired again after passage around the Moon in order to accelerate the spacecraft's return to Earth, and later for a minor course correction. As re-entry to Earth's atmosphere approached, NASA took the unusual step of jettisoning the Service Module first, while the Lunar Module was still attached to the Command Module. The LM thrusters were used to maneuver the CM/LM stack to point its windows at the departing SM, and photos were taken. When the crew saw the damaged service module, they reported that the access panel covering the O2 tanks and fuel cells had been blown off. There was some fear that the extensive condensation in the CM, due to reduced temperatures during the return leg, might have seriously damaged the electronics of the Command Module, which would become apparent upon activation. But the equipment worked perfectly when activated, at least partly due to the extensive design modifications made to the CM after the Apollo 1 fire. The crew returned unharmed to Earth, although Haise had a Urinary Tract Infection resulting from the scarcity of potable water on the damaged ship and the difficulty of disposing of urine, and had to be treated in an infirmary. While the crew was unfortunate to have this kind of major malfunction, they were still extremely lucky that it occurred on the first leg of the mission when they had a maximum of supplies, equipment, and power to use in the emergency. If the explosion had occurred while in orbit around the moon, or on the return leg after the LM had been jettisoned, the crew probably would not have survived. After the completion of the mission, there was a full investigation of the incident and the craft was modified to prevent future occurrences of the fault. Jim Lovell and Jeffrey Kluger's book about the mission, '' Lost Moon '', was later turned into a successful movie, '' Apollo 13 '', starring Tom Hanks , Bill Paxton and Kevin Bacon as the Apollo crewmen. Cause of the accident The explosion on Apollo 13 led to a lengthy investigation of the underlying cause. Thanks to detailed manufacturing records and logs of mission problems, the failure of the faulty oxygen tank was tracked to multiple faults that were not problems individually, but nearly led to disaster on this mission. Liquid gases are very difficult to handle, and most storage containers holding them are unsealed so that pressure from expanding gas will not cause the container to fail (much like freezing water in even the strongest sealed container will shatter it). Apollo's liquid oxygen tank was a marvel of Engineering , able to hold several hundred pounds of highly pressurized liquid gas to supply the craft with oxygen, fuel for Electricity (along with hydrogen) and Water from the by-product of the Fuel Cells . Left alone, the tank was capable of safely holding liquid oxygen under high pressure for years before it evaporated because of its design and insulation. Unfortunately, the very characteristic that made the tank useful made internal inspection impossible. The tank was made of several basic components that were relevant to the accident:
These were the basic design, manufacturing and operational problems that led to the accident.
MISSION NOTES
INSIGNIA The Apollo 13 logo featured three flying horses of Apollo's chariot across the sky, and the motto ''Ex luna, scientia'' (from the Moon, knowledge), and the number of the mission in Roman numerals. It is one of two Apollo insignias (the other being '' Apollo 11 '''s) not to include the names of the crew (which was fortunate, considering one of the original crew was replaced not long before the mission began). It was designed by artist Lumen Winter . He based it on a mural he had done for the St. Regis Hotel in New York; the mural was later purchased by actor Tom Hanks , who portrayed Lovell in the movie Apollo 13 , and now is on a wall of a restaurant in Chicago owned by Lovell's son. RELICS The command module is currently displayed at the Kansas Cosmosphere And Space Center , Hutchinson, Kansas . It was formerly at the Musée De L'Air Et De L'Espace , Paris . The lunar module burned up in Earth's atmosphere 17 April , 1970 , having been targeted to enter over the Pacific Ocean to reduce the possibility of contamination from a Radioisotope Thermoelectric Generator (RTG) on board (had the mission proceeded as planned, the RTG would have been used to power the Apollo Lunar Surface Experiment Package , and then remained on the Moon). The RTG survived reentry (as designed) and landed in the Tonga Trench . While it will remain radioactive for approximately 2000 years, it does not appear to be releasing any of its 3.9 kg of radioactive plutonium. {Link without Title} NASA has expressed a wish that the RTG be recovered. DRAMATIZATION
GAMES
EXTERNAL LINKS
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