Two Russians and an American on Tuesday blasted off for the International Space Station (ISS) on a Soyuz rocket in Russia's first manned space launch for almost five months.

Russians Gennady Padalka and Sergei Revin and American Joseph Acaba started their journey on top of the Russian Soyuz FG rocket under crystal-clear skies from Russia's Baikonur cosmodrome in Kazakhstan, an AFP correspondent said.

Their Soyuz TMA-04M capsule was successfully delivered into orbit, with the rocket stages detatching as planned, and all the crew were feeling good, mission control said.

They are due to arrive at the space station after a two-day journey on Thursday morning.

Russia is now the sole nation capable of transporting humans to the ISS after the withdrawal of the US shuttle but this blast-off was the first manned flight from Baikonur since December 21.

The launch had been delayed by one-and-a-half months after the spacecraft the three spacemen were initially to use in the mission was shown in testing not to be hermetically sealed and could not be used for safety reasons.

As a result, their mission has been cut down to 126 days but according to Padalka it will be extremely intense with 40 experiments planned on the Russian segment of the station alone.

Russia's space programme has been beset by a litany of technical problems which have led to the loss of a half dozen satellites and vehicles over the last year, including a Progress cargo vessel bound for the ISS.

The Soyuz rockets -- the workhorse of the Russian space programme and the direct descendant of the rocket that took Yuri Gagarin into space in 1961 -- were grounded after the Progress crashed into Siberia after launch.

However all manned launches since Russia resumed using the Soyuz have been textbook and hitch-free.

On board the ISS, the three newcomers will join Russian cosmonaut Oleg Kononenko, NASA astronaut Don Pettit and Dutch astronaut Andre Kuipers who have already been on the station almost five months since their December launch.

Together, the crew is set to have the historic task of receiving the first ever cargo consignment for the ISS delivered by a private company.

Private firm SpaceX is seeking to launch its Dragon spacecraft on May 19 from Cape Canaveral, Florida in what the company hopes will be the first step towards an eventual private manned mission to the station.

Padalka, who is making his fourth space flight, is one of Russia's most experienced and decorated active cosmonauts who has already spent 585 days in space and made eight spacewalks.

He made his first space flight back in 1998, serving on the now defunct Russian space station Mir. He flew to the ISS again in 2004 followed by another long duration mission in 2009.

Acaba had previously made one shuttle flight while Revin is making his first trip into space.