A US astronaut and two Russian cosmonauts have blasted off in pre-dawn darkness, riding into orbit on a Soyuz craft emblazoned with the portrait of the first man in space in celebration of the 50th anniversary of Yuri Gagarin's historic flight.
As the Soyuz TMA-21 launched from the Baikonur cosmodrome as scheduled, it turned the darkness into broad daylight for several moments and warmed the chilly steppe of Kazakhstan with a bright orange glow.
About nine minutes into the flight to the International Space Station, officials announced that the spacecraft had successfully reached orbit.
"They're feeling very good. They're very happy," said Nasa astronaut Nicole Stott, who watched the launch from the viewing platform.
Ms Stott has been on two space flights, including the final mission of Space Shuttle Discovery, which landed on March 9.
Live footage on Nasa TV showed that a small stuffed dog hanging in front of the crew had begun to float, an indication of the weightlessness of space. The toy dog had been given to the Russian commander, Alexander Samokutyayev, by his daughter.
Mike Suffredini, head of Nasa's International Space Station programme, said the launch went off completely as planned.
"It was perfect, quite appropriate for the anniversary," he said at Baikonur.
The launch from Russia's cosmodrome in Kazakhstan was the first for Mr Samokutyayev and Andrei Borisenko. The Nasa astronaut travelling with them, Ron Garan, had made one previous trip into space, on a US space shuttle mission in 2008.
They are to travel for two days before joining three other astronauts already aboard the orbiting space laboratory: Russia's Dmitry Kondratyev, Nasa astronaut Catherine Coleman and Italy's Paolo Nespoli, who have been there since December.