Astronauts from Russia, Japan and the US have docked successfully with the International Space Station (ISS) under six hours after they launched, NASA has said.

The Soyuz rocket - carrying cosmonaut Oleg Kononenko, US astronaut Kjell Lindgren and Kimiya Yui of Japan - had roared skyward from Russia's Baikonur cosmodrome in the barren Kazakh steppe at 21:02 GMT on Wednesday.

"We have contact," an announcer on NASA television said, as the craft soared high above the coast of Ecuador, 402km over the Pacific.

One solar array - a type of power supply that captures energy from the sun - did not deploy on time, but this did not affect the rocket's flight as the others were still operating, the US space agency said.

Scientists and space enthusiasts around the world were watching the launch closely, and with some concern, since the mission had been delayed by two months because of a Russian rocket failure.

Russia was in May forced to put all space travel on hold after the unmanned Progress freighter taking cargo to the ISS crashed back to Earth in late April.

The ship lost contact with Earth and burned up in the atmosphere.

The failure, which Russia has blamed on a problem in a Soyuz rocket, also forced a group of astronauts to spend an extra month aboard the ISS.

Sigh of relief

Russian officials earlier breathed a sigh of relief, with the space agency Roscosmos saying that the third stage of the Soyuz rocket separated on time and the crew were "feeling well".

"Everything is okay, everything is according to plan," said veteran cosmonaut Fyodor Yurchikhin, providing live commentary of the liftoff on television.

A workhorse of space that dates back to the Cold War, the Soyuz is used for manned and unmanned flights.

"Training... check. Equipment... check. Rocket... check. Press conference... check. We are ready to fly!!" Lindgren, 42, said on Twitter before the liftoff.

Ahead of the launch, the three men met with 81-year-old cosmonaut Alexei Leonov, the first man to walk in space and one of the Apollo-Soyuz commanders.

Sending the first man into space in 1961, and launching the first Sputnik satellite four years earlier, are among key accomplishments of the Russian space programme and remain a major source of national pride in the country.

But over the past few years, Russia has suffered several major setbacks, notably losing expensive satellites and unmanned supply ships to the ISS.

In the US, NASA has funnelled $4.2bn to Boeing and $2.6bn to SpaceX to help the companies build a successor to the space shuttle and to encourage competition in the aerospace industry.

In the meantime, the world's astronauts fly to the ISS aboard the Soyuz rockets at a cost of $70m per seat.

Source: Agencies