Kelly, who is of Irish-Catholic descent, thanked the pope for his kind words. His wife, U.S. Rep. Gabrielle Giffords, had surgery to repair her skull Wednesday, four months after being shot in the head at a political event in Tucson, Arizona. She was nearly killed, yet managed to attend her husband's launch last Monday.

Kelly told the pope that borders cannot be seen from space and noted that down on Earth, people usually fight for resources. At the space station, solar power provides unlimited energy, ``and if those technologies could be adapted more on Earth, we could possibly reduce some of that violence,'' he said.

Benedict asked about the future of the planet and the environmental risks it faces, and wanted to know what the astronauts' most important message would be for young people when they return home.

Space station astronaut Ronald Garan Jr. spoke of the paper-thin layer of atmosphere ``that separates every living thing from the vacuum of space.'' And shuttle crewman Mike Fincke described how he and his colleagues ``can look down and see our beautiful planet Earth that God has made.''

``However, if we look up, we can see the rest of the universe, and the rest of the universe is out there for us to explore,'' Fincke said. ``The International Space Station is just one symbol, one example, of what human beings can do when we work together constructively.''

Near the end of the 18-minute conversation, Benedict expressed concern for astronaut Paolo Nespoli, whose 78-year-old mother died in northern Italy at the beginning of May while he was serving on the space station.

``How have you been living through this time of pain on the International Space Station?'' the pope asked.

   ``Holy Father, I felt your prayers and everyone's prayers arriving up here where outside the world ... we have a vantage point to look at the Earth and we feel everything around us,'' Nespoli replied in Italian.

Nespoli will end his five-month space station mission Monday, returning to Earth aboard a Russian Soyuz capsule.

He will bring back with him a silver medal that shuttle astronaut Roberto Vittori took up with him on Endeavour, that was provided by the pope. It depicts Michelangelo's ``Creation of Man,'' the painting on the ceiling of the Sistine Chapel.

Vittori floated the commemorative coin in front of him, then gently tossed it to Nespoli, positioned on the opposite end of the front row of astronauts.

``I brought it with me to space, and he will take down on Earth to then give back to you,'' Vittori told the pontiff. The astronaut said he prays in space ``for me, for our families, for our future.''

The long-distance papal audience was arranged by the European Space Agency and the Italian Space Agency. NASA provided technical support from Mission Control in Houston.

Inside the ancient frescoed halls of the Vatican _ where email wasn't even in wide use until a few years ago _ the call was received with visible awe.

The 84-year-old German-born Benedict chuckled when one of the astronauts began floating up at the end of the transmission. He waved to the U.S., Italian and Russian crew at the beginning and end of the call.

The Vatican spokesman, the Rev. Federico Lombardi, said the call was evidence of the pope's desire to communicate with people however possible, be it sending a text message with a prayer of the day or a YouTube channel playing church teachings.

Pope Paul VI sent a greeting to the moon with Apollo 11's Neil Armstrong and Buzz Aldrin in 1969, but it was in a silicon disk that contained goodwill messages from numerous countries and was left on the Sea of Tranquility. ``I look up at your heavens, made by your fingers, at the moon and stars you set in place,'' said Paul VI, quoting from Psalms 8.

Mission Control, meanwhile, was glowing. Flight controllers watched on monitors as the pope got set up for the interview.

``It was just an amazing event, really a beautiful event,'' said lead flight director Derek Hassmann.

Before gathering for the extra-special VIP call, the astronauts conducted an hour-long survey of the gouge in Endeavour's belly, using a 100-foot (30-meter) extension boom.

Mission managers ordered the inspection as a precaution, saying there was no reason to be alarmed by the damage generated by Monday's liftoff on Endeavour's final voyage. Experts on the ground immediately analyzed the 3-D images beamed down, and concluded the shuttle is safe for re-entry.

The extra safety checks were put in place following the 2003 Columbia disaster.

The gouge _ spanning two or three tiles _ measures just 3 inches (7.6 centimeters) by 2.4 inches (6.1 centimeters), and is less than an inch (2.5 centimeters) deep.

Similar damage was seen on a flight by Endeavour in 2007, and that, too, required no repair. By coincidence, that mission was commanded by Kelly's identical twin brother, Scott.

Still ahead for Kelly and his crew are three more spacewalks, the next one on Sunday. Landing is scheduled for June 1.