The Atlantis shuttle mission could not undock from the International Space Station (ISS) on Friday as Russian officials said the Russian segment was still experiencing problems following a computer failure.
"The shuttle has enough reserves for a (third additional) day", Vladimir Solovyov, a vice president of Russian space operator RKK Energia, said, adding the shuttle could stay at the ISS, though Mission Control was "not insisting on that".
With the steering system of the Russian ISS segment disabled by a computer failure caused on Thursday by a static discharge during one of the shuttle crew's planned space walks, Russian space authorities have contacted NASA to "consider the possibility of running the system from the US segment".
Permanent ISS crewmembers are trying to make the station's six computers work without the power units, which crashed following the discharge.
If they fail, Russia will launch the next scheduled Progress cargo ship on July 23, two weeks ahead of schedule, to deliver new power units.
Russian authorities said the station was under control, and all crewmembers felt well.