HOUSTON – As a computer programming analyst with NASA in the 1960s, Bernie Roush developed a software program that mathematically produced drawings of what the Apollo astronauts would see out of their spacecraft window at any given time in their missions.
“The bulk of this was for mission planning, for flight control orientation, and crew orientation before launch. It was a flight planning tool,” Rousch said.
But in April 1970, Rousch's program became mission-critical. Fifty-six hours into the Apollo 13 moon shot, an oxygen tank exploded, forcing the astronauts, Lovell, Swigert and Haise, to abandon the command module and use the attached lunar lander as a lifeboat.
“They were on the way to the moon, and they lost their electrical power, they’ve lost their oxygen, they can’t live in command module anymore, they have to use the LEM as a lifeboat, designed to maintain two people for two days, now it has to maintain three people for four to five day,” Rousch said.
With the onboard computers out, the crew was literally flying blind, but they could determine if the craft was in the right position by looking out its windows to see if the view matched Rousch’s digitally calculated drawings.
If they saw the sun and earth in the positions dictated by his program, the spacecraft was in the right place.
"It was not designed for that job. It turned out to be the only tool that was available,” Rousch said.
Rousch was called in at 2 a.m. to do the math and adjust the program so flight controllers could relay the information to the crew as they began reentry. One mistake and the spacecraft would burn up on hitting the atmosphere.
“It was a nail biter. A real nail biter. Until you saw the parachutes open, you didn’t know if they were coming back,” he said.
So it was high technology and high drama when the three astronauts safely emerged from the space capsule. And it was also, perhaps, the pinnacle of Rousch’s career.
“The rest of the 25 years were anticlimatic," he said.