This is WEEKEND EDITION from NPR News. I'm Scott Simon. A tall white rocket is still standing on a launch pad at Cape Canaveral in Florida. The rocket belongs to a company called SpaceX, and it was supposed to blast-off this morning, send an unmanned capsule on a mission to the International Space Station - the first time a personal spacecraft will try to visit the station. But the launch attempt fizzled out this morning in the last seconds of the countdown.