On July 20, 2002, the 33rd anniversary of the first moon walk, Thad and Tiffany - after driving all night from Houston - arrived in Orlando, where they expected to sell their loot. And just an hour before the sale, alone in their hotel room, they celebrated their crime.

"I take some of the moon rocks, and I put 'em underneath the blanket in the bed," recalled Roberts.

"You have sex on the moon rocks?" Rocca asked.

"Yeah. I never said anything, but I'm sure she could feel it. She never said anything directly, either, but it was more about the symbol of what we were doing - you know, basically having sex on the moon."

Thad Roberts ... desperate? delusional? Or just plain dumb? All kinds of questions come to mind, some more basic than others.

"By the way, is it uncomfortable to have sex on top of moon rocks?" Rocca asked.

"Yeah, it's more uncomfortable than not," replied Roberts. "But it wasn't about the comfort at that point. It was about the expression."

"And no one had ever had sex on the moon before."

"I think we can safely say that," Roberts said.

But the FBI doesn't buy that Roberts did it all for love. "My impressions of Thad are that, you know, he was a very bright, motivated student, one of his goals was to be an astronaut," said Nance. "And I think he had his foot in the door with NASA, was well on his way to reaching that goal. And then this one greedy event, you know, he threw his life away in one fell swoop."

The "buyers" in Orlando were FBI agents. Thad pled guilty and served six years.

He never again saw the woman he says he stole the moon rocks for. He says he doesn't know how he ever could have pulled the heist off ...

"I'm still trying to understand why you would do something so reckless," Rocca asked.

"Me, too, when you figure it out let me know," he laughed. "Me too, yeah. Because there's just no reason to do it, you know? No reason to go through with it. Sure, parts of it are exciting, parts of it are a good story. But yeah, I mean, your whole life, the chance of being an astronaut?"

But Thad Roberts is not looking back.

"I know your imagination may be part of what got you into trouble in the first place, but in your wildest dreams, what do you see for yourself in the future?" Rocca asked.

"Wildest dreams? Anything's possible," he said. "I think I'm gonna still make a run for space. The private industry is still maybe going on. This might be the big thing of our lifetime and if it is, I'm gonna try to find a way to go.

"Maybe I can go pick up a moon rock, legally this time!" he added. "One that I can keep, yep! Put on my mantle and not have to keep it a secret."

For more info: