An American astronaut and two Russian cosmonauts have boarded the International Space Station (ISS) to become the platform's first, long-term residents.

"It's a great moment for all of us," said the space station's commander, Bill Shepherd, as the crew boarded their new home.

William Shepherd, Sergei Krikalev and Yuri Gidzenko entered the ISS at about 1100 GMT, shortly after their Soyuz capsule had docked with the station's Zvezda module.

The three men set up a live, televised link with the Russian mission control centre outside Moscow to confirm all was well on the station. A giant screen in the centre showed the crew, dressed in blue uniforms with headphones over their ears, floating in mid-air.

"We feel fine inside the station," said cosmonaut Sergei Krikalev.

Alpha call sign

In a conversation with American space agency chief Dan Goldin, Commander Shepherd also said that the crew was doing well but had one request.

"The first expedition on the space station requests permission to take the radio call sign Alpha," Shepherd said, punching the air with his right fist. All three men beamed and clasped their hands in a show of unity.

Goldin seemed surprised, but granted temporary permission. Alpha has long been the crew's choice for a name for the platform, but the US space agency has resisted, preferring simply the International Space Station, or ISS.

Russian space officials in particular are not keen on the name. They disapprove because it signifies the first. For Russians, the 15-year-old Mir space station is No 1. They have suggested the ISS be called Beta or even Mir 2.

Battery repairs

On entering the station, Shepherd, Krikalev and Gidzenko had to turn on lights and life-support systems.

Russian space officials monitor the docking

Flight controllers intend to keep the crew's work schedule light in the first few weeks, although Krikalev already has battery repairs scheduled for Friday.

The American space agency, Nasa, expects it will take a while before Shepherd, Gidzenko and Krikalev feel truly at home.

They will be confined to two of the space station's three rooms until a shuttle mission next month arrives with giant solar panels that will provide all the necessary power.

Huge significance

When complete in 2006, the multi-billion-dollar space station will be the largest man-made structure in space, more than 100 metres long and weighing 450 tonnes, and clearly visible from the surface of the Earth.

The launch of the first, three-man crew - known as Expedition 1 - has generated huge excitement.

"This is a huge, huge event," said US astronaut Frank Culbertson, who is to command a space station mission next year. I can't believe after all these years we finally are doing what we've been working for so long. It's going to take a while, I think, for people to digest the significance of this."

Russian President Vladimir Putin called the 16-nation ISS programme a "clear and convincing example of mutually beneficial co-operation, which is capable of uniting people of different nationalities for solving key tasks in scientific progress".

Nasa chief Daniel Goldin said as he toasted the launch: "It's a wonderful day, not for America, not for Russia, but for the people who live on this planet."