Wednesday, April 13, 2011
Apollo 13 was the seventh manned mission in the American Apollo space program and the third intended to land on the Moon. The craft was successfully launched toward the Moon, but the landing had to be aborted after an oxygen tank ruptured, severely damaging the spacecraft's electrical system. The flight was commanded by James A. Lovell with John L. "Jack" Swigert as Command Module pilot and Fred W. Haise as Lunar Module pilot.
The mission was launched on April 11, 1970. Two days later an (April 13) explosion crippled the service module. To conserve its batteries and the oxygen needed for the last hours of flight, the crew instead used the Lunar Module's resources as a "lifeboat" during the return trip to Earth. Despite great hardship caused by limited power, loss of cabin heat, shortage of potable water and the critical need to jury-rig the carbon dioxide removal system, the crew returned safely to Earth on April 17. NASA called the mission a "successful failure".
The mission began with a little-known smaller incident: during the second-stage boost, the center engine shut down two minutes early. The four outboard engines burned longer to compensate, and the vehicle continued to a successful orbit.
En route to the Moon, approximately 200,000 miles from Earth, Mission Control asked the crew to turn on the hydrogen and oxygen tank stirring fans. Approximately 93 seconds later the astronauts heard a loud "bang", accompanied by fluctuations in electrical power and firing of the attitude control thrusters. The crew initially thought that a meteoroid might have struck the Lunar Module (LM).
In fact, the number 2 oxygen tank, one of two in the Service Module (SM), had exploded. The resulting pressure inside the compartment popped the bolts attaching an outer aluminum skin panel, which as it blew off probably caused minor damage to the nearby high-gain S-band antenna used for translunar communications. Communications and telemetry to Earth were lost for 1.8 seconds, until the system automatically corrected by switching the antenna from narrow-band to wide-band mode.
The damage to the Service Module made safe return from a lunar landing impossible, so Lead Flight Director Gene Kranz immediately aborted the mission. Considerable ingenuity under extreme pressure was required from the crew, flight controllers, and support personnel for the safe return.
If you do not know the story, I suggest seeing "Apollo 13" directed by Ron Howard and starring Tom Hanks. It has been noted as one of the most historically accurate films ever made. Even though the real phrase was "Ok, Houston, we've had a problem here." not "Houston, we have a problem.".
The incredible determination and ingenuity to get these brave men home is, in my opinion, the perfect example of what makes the United States great.
Dan Emplit WBFD