Aboard The Space Station, It's A Beautiful World

Enlarge this image toggle caption NASA NASA

The space shuttle Endeavour launched its final mission this week, a 16-day mission at the International Space Station. It's the second-to-last mission scheduled for the space shuttle program before it comes to an end later this year.

This trip has added significance for shuttle commander Mark Kelly. His wife, Arizona Rep. Gabrielle Giffords, is continuing her recovery from a gunshot wound received in an attack in January. She traveled to Florida to watch the launch before returning to Houston for more surgery.

On what may be his last trip into space, Kelly tells Weekend Edition Saturday host Scott Simon that it's sometimes hard to understand all the conflict on such an "incredibly beautiful planet."

Enlarge this image toggle caption Geoffrey Bennett/NPR Geoffrey Bennett/NPR

"This is a really hard thing to give up," he says of his time in Earth's orbit. "Just looking down, we've got a very fragile and beautiful place to live. We need to take care of it."

Expedition 27 flight engineer Cady Coleman arrived at the space station last December. "You would think that after six months that I might even be tired of it," she tells Simon. "I will tell you that it's always changing."

"During my time up here, we've had the earthquake and tsunami in Japan, the conflict in Libya, and the flooding in the South," she says. It's hard to reconcile how hard life is on the planet with the angelic view she has from above. "I'm not looking forward to giving that up."

Time Flies – That Is, It Orbits

Yet life on board the International Space Station speeds the time along. "It's a very busy place," Coleman says. "We've got, like, 130 experiments running — almost at the same time, some of them — up here on the space station."

In fact, the crew just installed a $2 billion cosmic particle detector called the Alpha Magnetic Spectrometer, which will hunt for dark matter, cosmic rays and antimatter galaxies.

"[It's] really a premier physics experiment that's supported by 16 different countries, 600 physicists," Kelly says. "They've been working on this thing — a lot of people — for a long time." Finally having it aboard the space station, Kelly says, is a "great day for science."

The astronauts stay busy keeping themselves in shape, too. "Just to maintain your bone mass, you need to exercise about two hours a day up here," Coleman says.

"So I would say every day is a busy day — and a great day — up here."

Shuttles Grounded, But NASA Can Still Take Off

Those great days are coming to a close — for the shuttle program, at least. Some wonder if the end of the program is NASA's final frontier, too. Not so fast, Kelly says.

"NASA is leading the way and will continue to do so," he says. "We are the lead partner on the International Space Station, and when humans go back to the moon and on to Mars, I'm sure it's going to be the United States and NASA that's leading that as well."

That includes the commercialization of launch vehicles so humans can still travel into orbit after the space shuttle program ends. "That's still NASA that's leading that project," he says, and hopefully it will expand space exploration efforts even more.

"So we're pretty excited about the future of NASA."