UTIAS - Bringing Apollo 13 Home

  • When an in-flight explosion damaged NASA’s Apollo 13 spacecraft en route to the Moon, the manufacturer of the craft’s lunar module turned to the University of Toronto Institute for Aerospace Studies (UTIAS) for critical advice.

    Houston, We’ve Had a Problem

    On April 13, 1970, an oxygen tank onboard the Apollo 13 spacecraft exploded and forced the astronauts to abandon their plans to land on the Moon. To return home safely, the crew would need to ration the damaged craft’s remaining oxygen and electricity and perform delicate in-space manoeuvres to survive the long trip home and successfully re-enter the Earth’s atmosphere.

    The Apollo 13 spacecraft was composed of three parts: a command module for re-entry into Earth’s atmosphere, a service module that provided life support and rocket thrust, and a lunar module meant to land on the Moon. The explosion had damaged the service module and had forced the astronauts to enter the lunar module and use it as a “lifeboat” while they circled the Moon en route back to Earth.

    The lunar module, however, was designed for use on the Moon – not as a lifeboat to ferry astronauts back to Earth. The lunar module could not survive re-entry into the Earth’s atmosphere so the astronauts would need to enter the command module shortly before reaching the Earth. They would then need to jettison the lunar module – something that had never been attempted so close to Earth.

    Answering the Call

    “A group of us at the University of Toronto Institute for Aerospace Studies (UTIAS) were having a routine staff meeting when a telephone call came from the company that manufactured the lunar module,” recalls Ben Etkin, a now-retired UTIAS professor. “The company needed to tell NASA how to safely detach the lunar module from the command module and they wanted our help.”

    NASA engineers had decided that they would pressurize the oxygen in the tunnel that connected the two parts of the spacecraft and use that pressure as a spring to separate the two components. They did not know, however, the correct amount of pressure to perform this manoeuvre safely. Using too much pressure could damage the re-entry hatch and threaten the lives of the astronauts. Using too little pressure could cause the two components to remain too close together during re-entry – another potentially fatal scenario.

    The lunar module’s manufacturer, Grumman Aerospace, contacted UTIAS because of its known expertise in shockwaves and aerospace dynamics. They asked for UTIAS to send them the most appropriate pressure values that evening for use on Apollo 13.

      “Our team got together and huddled up, did some theoretical analyses, used a little bit of guesswork and phoned them back with our answer,” says Etkin. “We assumed that they had called other experts as well, but it turned out that we were the only group that they had contacted! After Apollo 13 returned safely to Earth, we received a letter from Grumman Aerospace thanking us for our participation and stating that our estimates had been the main quantitative information used to separate the components.”

    With the help of the UTIAS calculations, the separation of the two Apollo 13 components was a success and the astronauts returned safely to Earth on April 17, 1970.

    In April 2010, during ceremonies marking the 40th anniversary of the accident, Apollo 13 astronaut Fred Haise sent the following message to the UTIAS team:

    Let me join others in congratulations to the University of Toronto Institute for Aerospace Studies as the recipient of this year’s Air & Space Pioneer Award. As the Lunar Module Pilot on Apollo 13, I would certainly vouch for their credentials. Their study and calculations provided a safe means to utilize pressure in the tunnel area between the Command & Service Module (CSM) and the Lunar Module (LM) to assure safe separation of the LM without damaging the hatch. This was another one of the new procedures that had to be implemented on Apollo 13 to assure our safe return. My sincere thanks and congratulations again on your well deserved award!"
     – Fred Haise, Lunar Module Pilot, Apollo 13

    To learn more about UTIAS, visit the UTIAS website.