Technicians on Sunday successfully swapped out two bolts securing a crucial communications antenna on space shuttle Atlantis because engineers thought they were too short. The last-minute change-out was not expected to affect the schedule for Atlantis' planned launch next Sunday on a mission to resume construction on the international space station. "Everything went well and we're good to go," NASA spokeswoman Tracy Young said. The work began Friday evening and wrapped up Sunday afternoon. Technicians had to build scaffolding on top of a platform six stories above the ground in order to get in the shuttle's cargo bay and reach the KU-band antenna, which transmits images and other essential data between the space shuttle and Mission Control.