By Jeff Olson
America’s space program has been a mixture of successes and failures over the past 60 years, but such is the nature of any scientific endeavor in which progress is made. This week we highlight an event which is considered both a failure and a success. Each aspect proved beneficial to America’s future in space and combined to be one of NASA’s finest hours.
Space missions involve many more people than just the astronauts. Engineers, technicians and specialists of various disciplines, medical personnel and even those who actually manufacture the components of the spacecrafts all have integral roles in the outcome of a project and mission. To my knowledge, no better example of this exists than Apollo 13. Many of us still remember how much this event captured the attention of the world. Afterward though, as time went on for the next 25 years, most Americans probably gave it little thought anymore. However, that changed 25 years ago with the release of the motion picture Apollo 13. This film not only shed light on the events of this mission and featured what some consider to be the greatest real-time engineering feat in history, but it also reminded us of many of the people that it took to bring James Lovell, Fred Haise and Jack Swigert back home alive.
On August 6, 1969, NASA formally announced the crews for Apollo 13 and 14, the third and fourth Moon landing missions. At the time of the announcement, Apollo 13 was planned to launch in March 1970 and to land at the Fra Mauro region in the lunar highlands. The plan was for Lovell and Haise, after landing, to conduct geologic surveys and set up scientific experiments during two space walks while Mattingly remained in lunar orbit conducting photographic surveys of the Moon. Days before the mission, backup lunar module pilot, Charles Duke, inadvertently exposed the crew to German measles. Command Module Pilot Ken Mattingly had no immunity to measles and was replaced by backup command module pilot, John Swigert.
Fifty years ago this week, 2:13 pm. EST. April 11, 1970, Apollo 13 launched from the Kennedy Space Center. Although there were some minor issues during the first two days of flight, things generally went pretty smooth. At 46 hours, 43 minutes Joe Kerwin, the capsule communicator on duty, said, “The spacecraft is in real good shape as far as we are concerned. We’re bored to tears down here.” Well, they wouldn’t be bored for long. At nearly 56 hours into the flight on April 13, Mission Control asked Apollo 13 to run through some standard checks, one of which was to stir up the cyro tanks. The purpose of this was to give more accurate readings of how much oxygen and hydrogen gas was left. Right after the stir, oxygen tank No. 2 blew up, causing the No. 1 tank to also fail. The command module’s normal supply of electricity, light and water was gone. At 9:08 pm, Swigert responded to a warning light that accompanied the explosion. “Houston, we’ve had a problem here.” The warning light indicated the loss of two of three fuel cells, which were the spacecraft’s prime source of electricity. One oxygen tank appeared to be completely empty and there were indications that the oxygen in the second tank was rapidly depleting.
Thirteen minutes after the explosion, Lovell noticed the final evidence pointing toward potential catastrophe. “We are venting something out into the… into space,” he reported to Houston. It was oxygen gas escaping at a high rate from the second and last oxygen tank. At this point the crew started preparing to move their operations to the Lunar Module (LM) which would become a lifeboat.
For the next four days, the ground controllers in Houston faced a formidable task. Many new procedures had to be written and tested in the simulator before being conveyed to the crew. The list of problems to solve far exceeded what can be addressed here but, when it was all said and done, it came down to American ingenuity and, I believe, thousands of prayers from all over the world.
After an intensive investigation, the Apollo 13 Accident Review Board identified the cause of the explosion. In 1965, the Command Module had undergone many improvements that 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. Other warning signs during testing went unheeded and the tank, damaged from eight hours of overheating, was a potential bomb the next time it was filled with oxygen. That bomb exploded on April 13, 1970.
The Apollo 13 Mission was considered “A Successful Failure” for two reasons: While the original mission failed to be realized, the rescue of the crew was successful and perhaps a much a more consequential success than completion of the mission would have been. Also, the knowledge and experience gained in rescuing the crew would improve equipment design and quality and refine troubleshooting and quality control procedures. These would contribute towards better safety and more success in future missions.
The day after the splashdown, President Richard Nixon awarded the Presidential Medal of Freedom to the crew and the Apollo 13 Mission Operations Team for their unyielding efforts during the mission.