CAPE CANAVERAL, Fla. - Six astronauts embark on a home improvement project this month. But there's no chance of a last-minute trip to Home Depot since they'll be 220 miles from Earth. The crew of the shuttle Atlantis, set to launch Aug. 27, will be delivering a 35,000-pound addition to the half-built international space station. The astronauts will get a little help from robotic arms for the heavy lifting, but gripping screwdrivers and bolts in bulky pressurized spacesuits isn't easy. "This has been described ... as one of the most difficult tasks ever attempted by humans and I'm here to...