The Russian Soyuz craft carrying three residents of the International Space Station (ISS) undocked early Saturday on its way back to Earth after a day's delay in the journey, US space officials said, dpa reported.
Soyuz undocked at 0202 GMT, and performed a separation burn to move 12 kilometres away from the space station, NASA said on is internet Twitter feed. At 0431 GMT, the spacecraft is to fire the rockets to bring it on a path to drop out of Earth's orbit.
The departure of the two Russian cosmonauts and one US astronaut was delayed because their Soyuz capsule could not undock from the station, the US space agency said.
Hooks and latches on the station's docking port would not open, delaying the undocking, which had been planned for Friday morning, the National Aeronautics and Space Administration (NASA) said.
NASA said that the space travellers had made repairs to fix the problem.
It was the first time in the station's history that a Russian Soyuz capsule had not departed from the station as planned. The problem comes shortly after a July incident in which an unmanned transporter lost control and veered past the ISS.
The crew is to land in Kazakhstan between 0520 and 0530 GMT on Saturday. The head of the Russian space agency Roskosmos, Anatoly Perminov, told the Interfax news agency that the crew of six currently on the ISS was in no danger.