The space shuttle Discovery is moving closer to the International Space Station (ISS) as it prepares for a planned docking to the ISS at 5:12:46 P.M. (Eastern Daylight Time). According to NASA, the shuttle was 1,310 miles (2,100 kilometers) out as of 11:54 A.M. and was gaining on the ISS by about 600 miles (965 kilometers) with every 90-minute orbit. A series of maneuvers and thruster firings will ease Discovery into position for rendezvous.
Discovery launched without event Sunday after myriad delays stemming first from concerns about gaseous hydrogen valves aboard the orbiter and then from an unrelated hydrogen leak at the launch pad. A further wrinkle arose yesterday when a wayward piece of space junk headed toward the ISS had NASA considering an avoidance maneuver for the station. But the space agency later determined that the object would sail safely past. (It did indeed pass without incident early this morning.) The shuttle mission is delivering materials, including a replacement unit for a urine-to-water recycling system and additional solar arrays, to double the station's crew capacity from three to six.
The docking will be broadcast on NASA TV, followed by the hatch opening and a welcome ceremony at 6:58 P.M.
UPDATE (5:49 P.M.): Docking occurred at 5:19:53 P.M. (EDT) over Australia.
Photo of Discovery and its robotic Canadarm courtesy of NASA TV