Photograph courtesy NASA
Space shuttle Discovery touches down at the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida. The runway is 15,000 feet (4,600 meters) long and 300 feet (90 meters) wide, about twice the size of the average commercial runway. The pavement is made of 16-inch-thick (41-centimeter-thick), high-friction concrete grooved to drain water and add extra friction. Scientists went a little overboard with the friction at first and had to grind down the pavement a bit after several complicated landings.