After months of delays due to weather and equipment woes, the space shuttle Atlantis blasted off safely last week and docked with the international space station orbiting 220 miles above Earth. The crew then unloaded their main cargo, a 17-ton addition to the space station, fitted with two panels to collect solar energy. During a six-hour space walk, astronauts Joe Tanner and Heidemarie Stefanyshyn-Piper connected the new sections power and data cables to the space station. The hookup was successful, but the astronauts lost a bolt, washer, and spring while they worked, and NASA expressed concern that the debris could tear holes in the spacecraft or in the astronauts protective suits. Two more space walks are planned during the 11-day flight. The space labs construction had been on hold since the Columbia disaster more than three years ago.