NASA TV/collectSPACE.com

Apollo 17 moonwalker Gene Cernan, left, gives a thumbs up to the astronauts on the International Space Station from Mission Control in Houston on Tuesday, Feb. 5, 2013.

By Robert Z. Pearlman, collectSPACE.com Editor

HOUSTON The last man to walk on the moon made an unexpected call to the most recent men to live in space this week during a visit to NASA's Mission Control room.

Gene Cernan, who in December 1972 commanded Apollo 17, the sixth and final lunar landing mission, was touring the Johnson Space Center here with some friends when he was invited by flight controllers to talk live with Expedition 34 commander Kevin Ford and flight engineers Chris Hadfield and Tom Marshburn in the U.S. Destiny laboratory on the International Space Station, 260 miles above the Earth.

"I didn't know I was going to be able to do this," Cernan told the station's crew during the visit on Feb. 5. The moonwalker, who was using a phone receiver to talk with the astronauts in space, could see Ford, Marshburn and Hadfield on the large screens at the front of the control center room.

The ISS residents were in turn able to see Cernan via live streaming video on one of their laptop computers.

"I'm personally proud," Cernan commented. "I'm at the age now where most of you were probably in diapers or knee pants when I went to the moon, but at least what we did worked because it inspired you to do what you're doing." [Apollo 17 Moonwalker Calls Space Station (Video)]

"I think I was 12 when you came home from the moon for the last time," Ford responded, "and you did inspire us for sure, just like whole world, frankly. Every place I go in the world, they know NASA because what you guys did back then that long ago."

Elbow room in space The space-to-ground conversation, which aired on NASA's television channel and was streamed through the space agency's website, showed Ford, Marshburn and Hadfield floating inside the orbiting laboratory with room to spare. And they were inside just one of the space station's dozen modules, which they share with three other crewmates, Russian cosmonauts Oleg Novitskiy, Evgeny Tarelkin and Roman Romanenko.

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Last moonwalker calls space station