Each plane fits one pilot and one tourist, who would pay 98,000 dollars for the experience of flying for one hour at altitudes up to 100 kilometers (62 miles).

"At the peak of its parabolic trajectory, passengers will experience several minutes of weightlessness and see the Earth from space," said the release.

The company said the space tourism market could "generate revenues of one billion dollars annually."

"We have already a hundred candidates who have put a deposit or even paid in full for those who want to be the first," said Eric Anderson, CEO of Space Adventures.

The plane, called Xerus, will be specially built to carry space tourists by XCOR Aerospace in Mojave, California. "We hope that it will be ready in three or four years," Anderson said, though the release noted that the completion of the plane depended on securing financing.

Then, after 18 months of testing, the Xerus would be ready for its first passenger.

It will be piloted, said Anderson, by former test pilots who have logged "thousands of hours" in the cockpit. "They are some of the best in the world," he said.

The Xerus will reach its sub-orbital heights using "XCOR's next-generation rocket engine and propulsion system using non-toxic propellants.

"XCOR's recent success with the EZ-Rocket had demonstrated their determination to push the envelope," said Anderson.

The public will get their first look at the EZ-Rocket, the Xerus prototype which flew its first test flight last week, at the AirVenture Air Show July 23-29 in Oshkosh, Wisconsin.

"Our experience building and flying the EZ-Rocket airplane has shown that we can fly rocket-powered vehicles multiple times per day with a small ground crew," said Jeff Greason, XCOR CEO.