'N Sync star Lance Bass' bid to become the world's third space tourist could be in jeopardy because of wrangling over the fee for his trip.

The pop idol is due to fly to the International Space Station (ISS) with the Russian space agency on 28 October at a cost of about $20m.

He's doing beautifully, he's kicking butt in every way

David Krieff Television producer

But the deadline for a payment to secure his spot was Tuesday, according to a Russian space agency official who spoke on condition of anonymity, and no payment was made.

The singer is currently training in Star City, outside Moscow, and Nasa is already planning for Bass and his cosmonaut crew to visit the Johnson Space Center in Houston later this month for a full week of training.

"We have a contract, but we don't have any money," Russian Aerospace Agency spokesman Konstantin Kreidenko said - although he did not confirm the Tuesday payment deadline.

Lucrative sponsors

A Los Angeles television producer, David Krieff, is planning a series about Bass' trip and has been gathering sponsors to help cover the flight fee.

A television series of Bass' exploits is planned

He says three sponsors have already committed between $5m to $15m each.

Mr Krieff would not identify them but said they include a "huge soft drink" manufacturer and referred to a conglomerate "like Procter & Gamble".

Mr Krieff blamed the delay in payment on Russian bureaucracy and paperwork problems, but shrugged off any threat to the mission going ahead.

"In my mind it's a lot of talk and posturing. That is their style and I can appreciate it. This is 100% going forward," Mr Krieff said.

"He's doing beautifully, he's kicking butt in every way. He's totally dedicated and everybody loves him there," Mr Krieff added.

Contract problems

Mr Krieff admitted that there had been a delay in transferring funds to Russia, but he said that this was because he had only received a copy of the contract via e-mail.

He said that a paper version of the contract was necessary.

Mr Krieff said that a television series entitled "Celebrity Mission: Lance Bass" was being planned.

The series will include six one-hour episodes showing the star undergoing his training and a two-hour special showing the launch and Bass in space.