Apollo 13

Apollo 13 (April 11th 1970 - April 17th 1970) is an inhabited lunar mission of the Programme Apollo. Cancelled following the explosion of a tank of Oxygen of the CSM during the way outward journey due to an attempt at mixing of this same tank. Its crew was obliged to continue the voyage to the economy, using the effect of sling of the Moon to ensure the way of return. The main issues were the remaining little of energy on board spaceship, the small quantity of water and the quantity of carbon dioxide in the LEM, which was planned for the survival of 2 team members and not 3 as it was the case. The engineers of NASA had to find a means of making pass a square object (a cartridge of Hydroxyde of lithium being used to filter the CO2) in a round conduit with the material present, which they made a success of. The Lem was used as lifeboat.

the survival of the 3 astronauts held as much the human exploit and engineering that miracle .

Course of the mission

Crew

Holders

Jim Lovell: commander;
Ken Mattingly : pilot of the Module of order (replaced by Swigert Jack because exposed to the Measles, that it had never had, before the mission);
Fred Hates: pilot of the lunar module.

Substitutes

John W. Young: commander;
Jack Swigert: pilot of the module of order, which will replace Ken Mattingly;
Charles Duke: pilot of the lunar module.

Anecdotes

On the official photograph of the crew (opposite), the astronauts appear in costume of city (and not in spacesuit) because of the change of pilot of the module of order at the last minute and of the lack of time (to put and remove the combinations took much time)
During launching, one of the 5 engines of the first stage of the Fusée Saturn V died out prematurely. The combustion of this stage was slightly prolonged to compensate for the loss of power.
Fred Haise developed a urinary Infection and arrived on Earth with Fièvre.

Causes of the accident

A meticulous investigation after the mission made it possible to determine the cause of the explosion of one of the tanks of Oxygène O₂:

This tank of oxygen number 2 had been originally assembled on another Module of Service. During its disassembling by a crane, the lapse of memory of loosening of one of the four attaching bolts distorted one of its conduits of draining.

During the preparation of the flight, it was envisaged to fill the tanks of the Module of Service in order to test them. These tanks were then drained, but the tank number 2 refused to be emptied.

the deviation of the conduit of draining was then detected but the tank was left in place because the waste pipe was to never be used in vol.

It was decided to overheat the tank number 2 in order to make leave oxygen by boiling. For that, heating resistances of the tank number 2 were lit during 8 hours to 65 Volt S, which was the electric standard for the tests of materials on the ground.

All the Apollo modules had been revised in order to function electrically under 65 volts for the ground tests, and under 28 volts once in vol. Malheureusement, the Rupteur S of the Thermostat S of the tanks of O₂ were forgotten: they were precisely two contactors which had as a function to cut the power supply of resistances of heating when the temperature exceeded 26° C in the oxygen tank.

During the draining of the tank number 2 of Apollo 13, the two interrupters melted while being welded, and were not any more able to fulfill their role.

Made worsening, the dial of the thermometer of monitoring of the temperature of the tank was graduated only until 26° C… since beyond the thermostatic interrupters were to fulfill their function and to stop the heating.

Ainsi during draining one estimated, a posteriori , that the temperature went up well beyond 600° C in the tank what vaporized insulators in Téflon wiring inside the tank.

When unhappy Jack Swigert actuated the mixing of the tank number 2, with the 55e hour, 54e minute and 53e second of the flight with: 321860 kms of the ground, it did not know that it was going quite simply to make spout out sparks starting from wiring maintaining with naked inside the tank.

the mixture of Teflon and oxygen, highly flammable, exploded the tank number 2 which damaged in the passing the conduits of the tank number 1, blocked the valves of engines of positional checking, and left the crew with very little electricity and water (manufactured starting from combustible batteries supplied with O₂).

Sources

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