Russian computers controlling the International Space Station's (ISS) orientation and supply of oxygen and water have failed, Nasa officials say.
The station's three crew and seven visiting shuttle astronauts are not at any immediate risk; the ISS has not lost all vital systems.
But it could force Nasa to extend the current shuttle mission by one day.
More: http://news.bbc.co.uk/2/hi/science/nature/6752459.stm
US astronauts have ended their second spacewalk, folding up old solar panels on the International Space Station.
The two shuttle Atlantis astronauts folded a solar wing to allow a new system of panels to rotate properly.
They should complete the work in the next walk on Thursday and a fourth walk on Friday will see if repairs are needed to the thermal re-entry blanket.
More: http://news.bbc.co.uk/2/hi/science/nature/6750359.stm