But Bass has yet to receive an official approval from the Russian space agency, Rosaviakosmos.
"I have not had a formal proposal. That's what we're waiting on," he said. "Nothing is certain, I think, with any mission, up to a week before it goes up, before they choose the final crew."
Bass, 23, shrugged off questions about dangers of space flight. ``I like to be positive, I'm an optimist,'' he told a news conference in Moscow. ``I know physically I can do it, I know mentally I can do it.''
Bass said he and another would-be space tourist, former NASA official Lori Garver, had spent weeks passing grueling tests to qualify for the mission with 48 doctors certifying their fitness at Russia's premier space medicine center, the Institute for Medical and Biological Problems.
Bass was found to have an irregular heartbeat, and although it was not necessarily a hindrance to a space mission, he had it corrected by a medical procedure back in the United States.
Bass said he had been dreaming about going to space since childhood and voiced hope that his mission would serve educational purposes through a documentary he would make in space.
"We're doing final negotiations right now with a major network to air this," he said. "It makes me feel like a great spokesperson for these space programs."
If given the stamp of approval, Bass will be the third man to pay his way into space aboard a Russian craft. Millionaire Dennis Tito became the first space tourist last year, followed in April by South African Internet magnate Mark Shuttleworth.
Both were widely reported to have paid $20 million, enough to cover the entire cost of a manned space launch.
Bass, the low voice of the five-member 'N Sync, said the space stint would not interrupt his recording schedule. The group finished their latest concert tour several weeks ago.
"It's amazing how perfect the timing was. We had just finished a tour and we were going to take the rest of the year off," he said, adding the other members had been supportive.
The band has proved one of the biggest pop sensations since 1998 when their debut album "'N Sync" sold 10 million copies.
Their March 2000 album "No Strings Attached" was the first in U.S. chart history to sell more than 2 million copies in its first week of sales.