The world's first space tourist, Californian businessman Dennis Tito, has entered the International Space Station - the climax of his 40-year dream.

Mr Tito and two Russian cosmonauts, Talgat Musbayev and Yuri Baturin, floated through a hatch into the space station, shortly after their Soyuz spacecraft docked.

Despite feelings of queasiness, the 60-year-old financier said he was having no trouble with weightlessness.

"A great trip here!" said a jubilant Tito. "I don't know about this adaption that they're talking about. I'm already adapted. I love space!"

The Russian Soyuz craft is now docked at the ISS

The millionaire beamed as he shook hands with the three space station residents and gave a thumbs-up.

"We're so glad that [the Soyuz crewmen] are finally here, so we have guests in our house," said Russian space station commander Yuri Usachev.

Safety fears

The Soyuz flight arrived at the International Space Station (ISS) just before 0800 GMT on Monday, two days after blasting off from Kazakhstan.

It docked within hours of the departure of the American shuttle Endeavour, which is now heading back to Earth. The US shuttle is scheduled to touch down on Tuesday at Cape Canaveral, Florida.

Mr Tito has paid $20m for the privilege of becoming the first space tourist. His arrival marks the beginning of six days of monitoring by the US space agency Nasa, which initially opposed the visit.

It was only in the days before take-off that Nasa finally lifted its objections to the trip, having expressed fears that his presence could jeopardise the safety of the ISS.

Tito has agreed not to enter the American section of the station unaccompanied. He also pledged to pay for any damage he might cause.

Computer glitch

Tito will play no part in the work carried out aboard the platform by his Russian companions or the three astronauts who have lived on the platform since March - American astronauts Susan Helms and James Voss, and their Russian commander.

The main aim of the Soyuz mission is to replace an existing capsule already docked to the ISS.

It follows the shuttle Endeavour's departure from the space station, a day after engineers finally revived a back-up computer needed to operate a new billion-dollar robotic arm on the ISS.

The 17.5 metre (58-foot) arm was used to complete what has been billed by Nasa as the most complicated robotic feat ever attempted in space - transferring a 1.5 tonne packaging crate to Endeavour's own smaller arm.

Tito has promised to pay for any breakages

The shuttle arm then placed the crate in Endeavour's cargo bay ready to return to Earth.

With that manoeuvre completed, the shuttle and its seven crew members departed from the ISS.

Nasa says all three of the command and control computers needed to operate the robotic arm are functioning, although the two back-up machines have hard drive problems.

Mission Control has now relieved the ISS crew of almost all its duties while ground engineers test the computers.

They will now have plenty of time to "entertain" the Soyuz visitors, according to Nasa official Bob Cabana.