Shuttle Endeavour has docked with the International Space Station to deliver a $2 billion particle physics experiment and parts and supplies, UPI quoted NASA as saying. Hatches between the shuttle and the ISS were opened about an hour ahead of schedule at 7:38 a.m. EDT, a NASA release said Wednesday. The Endeavour crew was led into the station by shuttle commander Mark Kelly, whose wife U.S. Rep. Gabrielle Giffords, D-Ariz., was shot in the head in January but has recovered to the point where she was able to travel to Florida under medical care to witness the shuttle's launch. The now combined shuttle/station crew of 12 will remain at the station until May 21, when ISS crew members Dmitry Kondratyev, Cady Coleman and Paolo Nespoli will return home to Earth with the Endeavour crew. After the completion of Endeavour's mission, NASA plans one final shuttle mission to the space station in July. When Endeavour returns to earth and is retired, it is scheduled to go on public display at the California Science Center in Los Angeles.