Astronauts float in space to fix space station

UNDATED (WHDH) -- Two astronauts floated in space Wednesday outside the international space station, trying to fix a power unit that is not properly installed.

The duo is working to fix a pair of stuck bolts on a new replacement power unit attached to the exterior of the station.

One of the astronauts is NASA's Sunita Williams who made headlines back in 2007 when she ran the Boston Marathon while orbiting earth on the space station's treadmill.