CAPE CANAVERAL, Florida: Space shuttle Discovery arrived at the International Space Station Saturday, making its final visit before being parked at a museum. “What took you guys so long?” asked the space station's commander, Scott Kelly. Discovery should have come and gone last November, but it was grounded by fuel tank cracks. It blasted off Thursday with just two seconds to spare after being held up by a balky ground computer. “Yeah, I don't know, we kind of waited until like the last two seconds,” said shuttle commander Steven Lindsey. The linkup occurred 220 miles (355 kilometers) above Australia. Discovery — flying on its final voyage — will spend at least a week at the orbiting outpost. It's carrying a closet-style chamber full of supplies as well as the first humanoid robot to fly in space. The compartment will be attached permanently to the space station early next week. Altogether, there are 12 people aboard the joined spacecraft, representing the United States, Russia and Italy. And in a historic first, four of the five major partners have vessels docked there right now, including cargo ships from Japan and Europe. The entire conglomeration has a mass of 1.2 million pounds (0.54 million kilograms), including the shuttle. It took longer than usual for the hatches to open because of a slight misalignment between the shuttle and station that needed to be corrected. The two skippers shook hands when the doors finally swung open, and there were hugs all around. It was a quick reunion. The astronauts rushed off to see how far they could get Saturday evening with the installation of a platform holding a spare radiator for the station. The giant shelf was carried up aboard the shuttle. They worked late, but finally got the platform installed, eight hours after the docking.