Posted: Sat, Jul 1, 2006, 4:54 PM ET (2054 GMT)

The first attempt to launch the shuttle Discovery on mission STS-121 was scrubbed Saturday afternoon because of weather. Discovery was scheduled to launch at 3:49 pm EDT (1949 GMT), but managers scrubbed the launch at the T-9 minute hold because of anvil clouds in vicinity of the spaceport. No technical issues prevented the launch, after shuttle managers decided that a heater problem with one of the shuttle's thrusters was not a serious enough issue to prevent the launch from proceeding. The next launch attempt, weather permitting, is 3:26 pm EDT (1926 GMT). The overall launch window remains open through July 19.