Australia was spectacular, astronaut says

NASA astronaut Colonel Robert Shane Kimbrough has told Aussie students he wishes Earth could be as serene as it looks from space.

After gazing down on Australia from space, NASA astronaut Colonel Robert Shane Kimbrough has had a close encounter with Queensland university students.

Col Kimbrough logged a total of 15 days in space, including 12 hours of spacewalks.

Walking outside the International Space Station, on the frontier of exploration and in temperatures ranging from lows of minus 150C to highs of 200C, wasn't frightening, he told students at the University of Southern Queensland on Wednesday.

"You don't think about all the bad things that could happen," he said.

During his downtime, Col Kimbrough would find the closest window.

"About every time I looked out I saw Australia. I don't know why, but it just happened to work out that way.

"It looks lovely, you can see the vast expanses, it's kind of a brownish green from up there ... spectacular."

He grew up in the era when the Apollo astronauts walked on the moon and says he always wanted to go to space.

When he blasted off in the shuttle Endeavour for the first time on November 14, 2008, he remembers laughing uncontrollably.

"It was the greatest ride of my life," Col Kimbrough told AAP.

Col Kimbrough said seeing Earth from space had a powerful effect.

"When I was looking down at the planet one thing I noticed is that you don't see borders, you don't see all the war going on. It just looks really peaceful up there.

"You can see the thin layer of atmosphere that protects us and keeps us all alive.

"I really wish we could get to that sense of serenity on the planet, instead of just off the planet."