A Soyuz rocket carrying two Russian cosmonauts and a United States astronaut failed to dock as planned early on Wednesday to the International Space Station (ISS), the Russian and US space agencies said on Wednesday, citing a problem on approach.
The rocket, which took off without a hitch on Tuesday from Russia's Baikonur launching pad in Kazakhstan, was meant to have hooked up with the ISS at 0304 GMT Wednesday after a six-hour flight.
It will now seek to dock at 2358 GMT on Thursday, Russia's federal space agency Roscosmos said, according to Russian news outlets.
The delay "is due to complications that appeared in the functioning of the vessel's orientation system," Roscosmos said.
The US space agency NASA said in a statement on its website that the Soyuz spacecraft "was unable to complete its third thruster burn to fine-tune its approach" to the orbiting space station.
As a result, the rocket is reverting to a backup docking window.
"Rendezvous experts are reviewing the plan, and may update it later as necessary," the US space agency said, adding that the trio on board were "in good spirits".
It added that the three personnel awaiting them on the ISS – from Russia, the United States and Japan – "were informed of the new plan" and standing by. The three from the Soyuz will be staying on the orbiter for half a year.
Rocket not oriented properly
NASA said Russian flight controllers were reviewing data to work out why the third thruster burn did not occur.
"Initial information indicates the problem may have been the spacecraft was not in the proper attitude, or orientation, for the burn," NASA said.
After the retirement of the US shuttle, NASA is for now wholly reliant on Russia for delivering astronauts to the space station on its tried-and-trusted Soyuz launch and capsule system.
Russians Alexander Skvortsov and Oleg Artemyev along with Steve Swanson of NASA took off in the spectacular night-time launch.
Up until the docking problem, this latest Soyuz mission was most notable for underlining continued US-Russia space cooperation despite the diplomatic standoff over Ukraine.
US-Russia space cooperation
Space officials have made clear that space cooperation – one of the few areas of genuine mutual work between Russia and the United States – will continue unaffected by the mounting diplomatic strains that have seen the US impose sanctions on Russian officials over Moscow's annexation of Crimea.
At the pre-flight news conference at Russia's Baikonur cosmodrome in Kazakhstan, senior astronauts Skvortsov and Swanson said that they had decided to have dinners together on board the ISS "as an opportunity to come together as friends in the kitchen and look each other in the eye".
Skvortsov, whose name originates from the word "starling" in Russian, said he would be able to live in harmony with the "swan" Swanson.
"In nature these birds exist together very peacefully. I do not think we will have any problems. I think we will all be able to live peacefully together," he said.
Swanson also paid hommage to Yuri Gagarin, the Soviet cosmonaut who became the first man in space in 1961 with his flight from Baikonur.
"Yuri is a symbol for the whole world. I am proud to be part of history here," he said.
Skvortsov is making his second space flight and Swanson, a veteran of two past shuttle missions, his third.
Artemyev meanwhile is making his first voyage to space. He took part in a 2009 experiment where volunteers were shut up in a capsule at a Moscow laboratory for 105 days to simulate the effects of a possible voyage to Mars.
After docking, the trio will bring the ISS crew up to six by joining on board incumbent crew Koichi Wakata of Japan, American Rick Mastracchio and Russian Mikhail Tyurin.