A warped wheel, a loose sprocket, and a bloody finger were a few of the challenges that reared up against the Canadian teams at NASA’s Great Moonbuggy Race in Huntsville, Ala., Friday.

Space shuttle Discovery’s astronauts were doing last-minute checks of their flight system Friday in anticipation of Saturday’s return to Earth when NASA would have the chance observe the effects of a deliberately flawed thermal tile on the shuttle’s exterior.

NASA and astronauts aboard the International Space Station have successfully extended the station’s new set of solar wings on Friday, a process that will double the amount of electricity available for science experiments on the orbiting outpost.

NASA’s Discovery space shuttle took off Sunday evening from the Kennedy Space Center in Florida for the International Space Station after the mission was delayed for a month by technical problems.

Hit by more valve trouble, NASA postponed the launch of the space shuttle Discovery, just hours before it was to head to the space station Wednesday, because of a hydrogen gas leak.