|The flight path of the Soyuz TMA-12M rocket (AFP-Yonhap)|
The two Russian cosmonauts and American astronaut were to have docked with the ISS early Wednesday just six hours after launch from Kazakhstan but the problem means that the docking is now only planned on Friday.
This means that the trio will now orbit the Earth 34 times before their rendezvous with the international space laboratory, instead of the fast track route of four orbits originally envisaged.
Russians Alexander Skvortsov and Oleg Artemyev along with Steve Swanson of NASA had earlier taken off from Russia’s Baikonur cosmodrome in Kazakhstan in the spectacular night-time launch that initially went without problem.
The issue appeared to arise once their Soyuz capsule was in orbit and a thruster failed to fire to assist its approach for docking with the ISS.
The 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.
The trio were using a fast-track approach to the ISS that Russia has been employing since 2013. After the problem, they are now using the traditional two-day longer approach that was employed up to 2012.
“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.”