Jerry Elliott High Eagle served with NASA and played a key role in the Apollo 13 rescue. Here’s more from Transportation History:

During his time at that agency to date, Elliott has worked extensively on the Gemini, Apollo, and Space Shuttle spaceflight programs. One of his highest-risk and best-known contributions to NASA efforts took place in 1970 during the flight of Apollo 13 to the Moon for a landing there.

After the explosion of an oxygen tank on board Apollo 13 had severely damaged its service module, Elliott worked feverishly with his NASA colleagues back on earth to rescue that spacecraft mission’s crew from a life-threatening situation. As the lead retrofire officer at the NASA Mission Control Center at the time, Elliott played an instrumental role in computing the spacecraft trajectory that allowed those endangered astronauts – James A. Lovell, John L. “Jack” Swigert, and Fred W. Haise – to return safely to earth.

From his personal journals, published in an article in Winds of Change:

“Actual landing coordinates for Apollo 11 to Apollo 15. The ones entered for Apollo 16 were predicted, since the mission had not yet been launched”:

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