ISS Astronauts Invite Pope to Space on NASA-Streamed Live Call

Life as an astronaut is full of challenges: grueling physical trials; mind-bending experiments conducted in conditions like nothing on Earth; eating that weird dehydrated ice cream you get at the NASA gift shop.

But for 60-year-old Paolo Nespoli, an Italian national aboard the International Space Station (ISS), Thursday brought a new kind of test—a hardball philosophical discussion with one of the religious world's greatest minds: Pope Francis himself.

In a 20-minute conversation streamed live by NASA and the Vatican and marred only by one brief loss of communication, the pontiff spoke with each of the six astronauts currently aboard the orbital research center.

Nespoli acted as a translator between Pope Francis, who spoke in Italian, and his colleagues, as the Argentine priest asked a series of questions about the crew's reflections on their time off the Earth and each responded.

The Italian astronaut answered the first question from Francis, "In light of your experiences in space, what are your thoughts regarding the place of man in the universe?"

The Italian said that as an engineer "among experiments and machinery and equipment," he remained "rather perplexed" over "internal" questions. "The more we know, the more we realize how little we know," he said.

"I would like so much that people like yourself," Nespoli continued, giving the example of poets, writers, philosophers and theologians, "could also come into space, this certainly is what the future will provide."

He told the pontiff, "I'd like to see you here to explore what it means to have a human being in space."

Randy Bresnik, a 50-year-old American, said that space travel allows one "to be able to look outside and see God's creation maybe a little bit from his perspective."

"People cannot come up here and see the indescribable beauty of our Earth and not be touched in their souls," he added.

"There are no borders, there's no conflict, it's just peaceful, and you see the thinness of the atmosphere. It makes you realize how fragile our existence here is," Bresnik continued.

The pope agreed: Earth, he said, "Is a very fragile thing…a very fine and thin atmosphere, and that is so capable of destroying itself, of doing bad things."

Mark Vande Hei, another American, age 51, answered a question from Pope Francis on what had surprised him during his time on the ISS.

"What surprised me is how approaching something from a different perspective can make something that's very familiar seem unrecognizable," Vande Hei said.

He said he was yet to grow used to the process of moving in zero gravity. "To get my bearings, I still have to decide which direction to perceive as up in order to make sense of things," he said.