The latest civilian to join a space station crew is U.S. businessman Gregory Olsen. He  launched on a Russian Soyuz spacecraft from Baikonur, Kazakhstan Saturday with cosmonaut Valery Tokarev and U.S. astronaut William McArthur.

Gregory Olsen during news conference at Baikonur Cosmodrome in Kazakhstan

Mr. Olsen is the third non-professional astronaut to make the trek to the space station, following American Dennis Tito in 2001 and South African Mark Shuttleworth in 2002. There is a phrase for such adventurers - space tourist. Mr. Olsen admits that he will spend considerable time looking at Earth from aloft.

"I'm looking forward to getting up there and being weightless and looking at the Earth from a higher vantage point and doing whatever observation I can from the space station," he said.

But Mr. Olsen will do more than just tour and look casually out the window. The U.S. space agency NASA, which calls him a space participant, says that for the week he will be aboard the space station, his observations will have a scientific purpose - remote sensing and infrared astronomy. That is befitting for his background as an electrical engineer who founded a New Jersey company called Sensors Unlimited, that produces electronic optical devices for fiber optic communications systems.

"I have a lot of scientific and engineering experience, but none in space yet," he said. "Whatever I do, there will be some observation, whether it's in the optical or near-infrared."

US astronaut William McArthur, center, Russian cosmonaut Valery Tokarev, right, and US space tourist Gregory Olsen, left, wave after news conference at Baikonur Cosmodrome

Mr. Olsen has trained for two years in the United States and Russia for this chance, for which he paid the Russian space agency $20 million. His mission was to have taken place last year, but was delayed because of an undisclosed medical problem, which he describes as minor.

"That has subsequently gone away and I have been evaluated many, many times and given a clean bill of health," he said.

Gregory Olsen is a grandfather old enough to remember the beginning of the space age. He says he always wanted to go to space, inspired by the Russian Sputnik launch of 1957 and the subsequent U.S. Apollo moon landing program. After Dennis Tito and Mark Shuttleworth went to the space station, he contacted the Washington, D.C.-area company Space Adventures, which brokered the deal with Russian space officials, as it did for the others.

"I thought, 'This is something I could do.' It was the right time of my life," he said. "I've sold my company, my daughters are grown up and have children of their own. I was looking for the next chapter in my life and this looks like it's going to be a really big one, so I'm just happy to be there."

Mr. Olsen's adventure ends after eight days in orbit when he returns to Earth with the outgoing crew of the space station, astronaut John Phillips and cosmonaut Sergei Krikalev.