The first private manned rocket reached space Wednesday after an unexpectedly bumpy ride in a bid to earn a $10 million prize.

During its 81-minute flight, SpaceShipOne (search) climbed to an unofficial altitude of more than 330,000 feet — about 2,000 feet above its target altitude of 62 miles. The craft made more than two dozen unexpected rolls during its ascent, corkscrewing upward.

"Now that was fun," astronaut Michael Melvill (search) said after the ship landed safely at Mojave Airport. "I thought I really nailed it."

Melvill said he shut down the engine 11 seconds earlier than planned after determining the ship would reach its target altitude.

The ship glided back to the airport and landed at 8:33 a.m. PDT. Official confirmation of the altitude reached was expected about two hours after landing.

SpaceShipOne designer Burt Rutan (search) said controllers had asked Melvill to shut the engine down early because of the rolling problem, but Melvill kept going until he was certain he would reach the target altitude.

Rutan said the roll problem would be studied and a determination made about delaying a second flight set for Oct. 4 that is also required to win the Ansari X Prize (search).

"We actually had the roll that we didn't expect late in the game there," Rutan said. "We actually were asking him to go ahead and abort, to shut it off to where he wouldn't have gone the (62 miles)," Rutan said. "He stayed in there just for a handful of seconds more."

Melvill said he may have caused the rolling himself.

"You know, you're extremely busy at that point," he said. "Your feet and your hands and your eyes and everything is working about as fast as you can work them, and probably I stepped on something too quickly and caused the roll. But it's nice to do a roll at the top of the climb."

SpaceShipOne soared into space moments after dropping away from its mothership above Mojave Airport, fired its rocket and pulled into a vertical climb. The specially designed jet with the ship under its belly took off at 7:12 a.m. from the airport in the desert north of Los Angeles.

At 47,000 feet, SpaceShipOne was released into a brief glide before Melvill fired its rocket motor and pointed the nose up toward space.

A crowd of invited of VIPs watched from below the airport control tower, while news media watched from bleachers along the runway. Spectators, some wrapped in blankets to ward off the early morning chills, erupted in cheers as the spacecraft and its chase planes taxied down the runway.

Among those watching was Adam Smith, 14, of Vienna, Va., who has earned $1,000 this summer toward a down payment to a company called Space Adventures, which is taking reservations for future space travel. Smith said he's had an interest in space "as far back as I can remember." He committed to raising the money after finding the company's Web site earlier this year.

"It was just one of those things — I want to do this," the 9th-grader said.

Melvill earned the nation's first commercial astronaut's wings by piloting SpaceShipOne's history-making flight in June.

The Ansari X Prize will go to the first craft that safely completes two flights to an altitude of 328,000 feet, or 62 miles, in a 14-day span.

During the ship's first flight in June, history and the record books were on the line. Now it's about the money — a $10 million payoff for years of secret work.

SpaceShipOne was flying with a pilot and the equivalent weight of two passengers aboard in accordance with rules requiring X Prize contenders to be capable of carrying three people on a suborbital hop into space.

The Ansari X Prize was modeled after the $25,000 Orteig Prize that Charles Lindbergh (search) won in his Spirit of St. Louis for the first solo New York-to-Paris flight across the Atlantic in 1927.

The St. Louis-based X Prize Foundation, noting the rapid development of air travel after Lindbergh's feat, hopes to inspire an era of space tourism in which spaceflight is not just the domain of government agencies such as NASA.

The idea appeared to be working far faster than might have been expected.

Maverick aerospace designer Burt Rutan, with more than $20 million in funds from Microsoft billionaire Paul Allen (search), secretly developed SpaceShipOne and is well ahead of two dozen teams building X Prize contenders around the world.

And already the ultimate goal of the X Prize appears in sight.

Richard Branson (search), the airline mogul and adventurer, announced in London on Monday that his Virgin Group (search) plans to offer passenger flight into space aboard rockets based on SpaceShipOne by 2007.

Branson believes he will fly some 3,000 people into space in the first five years that Virgin Galactic spaceline is operating.