This is what Buzz Aldrin was thinking when he left the moon

As the second man to walk on the moon, Buzz Aldrin has described what it was like to take his historic first steps.

But what was he thinking when he left?

When Business Insider asked this question, he started singing a song:

"'Oh man, I wanna go home,'" he sang. "Now that's not the right tune. 'I wanna go home.'"

It sounded a bit like "Sloop John B," which the Beach Boys released in 1966. This would make sense, since they touched down on the moon July 20, 1969 - 48 years ago this week.

"We were successful doing what we were sent there to do," Aldrin said. "And so when we were cleared for liftoff, I said, 'Roger, Houston, we're No. 1 on the runway.' Now that's a humorous absurdity, but that was the state of mind I was in because we had fixed the circuit breaker problem."

The circuit breaker on the lunar module turned the ascent engine on, so Aldrin and Neil Armstrong would need it to get back to Apollo 11 orbiting around the Moon so they could return to Earth.

At some point, the circuit breaker broke, but Aldrin was able to activate it (and the engine) with a felt-tip pen.

And then they were ready for liftoff. "I wanna go home," Aldrin said.