The first privately owned passenger spaceship is on track for a test flight beyond the atmosphere this year, and nearly 500 people have signed up for rides.

Another company just closed on $5 million equity financing, enough to finish building a two-seater rocketplane called Lynx.

Both firms -- and a half-dozen more -- are looking at flying not just people, but experiments and payloads owned by research laboratories, businesses and educational institutes.

"There are fascinating businesses that may come that would be tremendously exciting," said Carissa Christensen, managing partner of the Tauri Group, which is working on a commercial space market study to be released in May. "There also are tremendous financial challenges, requiring enormous capital, and there are risks," she said.