``The International Space Station is a wonderful example of cooperation among nations, all of whom have the future of our planet at heart. More and more we realize that we are all interlinked, all interdependent,'' said Mandela, a Nobel Peace laureate.

Shuttleworth, who repeatedly addressed Mandela by his clan name, Madiba, said watching Earth from space made him realize how fragile and beautiful the planet was.

``Looking at Africa from space is truly inspirational,'' Shuttleworth told Mandela. ``It's clear to me that there is much work to be done but much hope for the future.''

Shuttleworth said the most breathtaking site he's seen so far was the Southern Lights, which he described as ``great green waves in the sky.''

``It was the most exquisite thing,'' he said.

Shuttleworth was surprised when a 14-year-old South African girl, a guest of Mandela's for the interview, "popped the question" to the high-flying mogul.

"I was wondering if you would like to marry me," Michelle Forster asked.

Forster was diagnosed with cancer two years ago and one of her legs has been amputated. She uses a wheelchair.

Shuttleworth politely dodged the query, telling Forster he was "very honored at the question" before inquring about her future interest in space.

"I hear that you would like to be an astronomer one day, you would love it in space," Shuttleworth said before moving on to discuss his space experiences.

Shuttleworth, the first African citizen in space, has already spoken to President Thabo Mbeki from the space station. He is hoping his flight will encourage more African children to study science and math.