CAPE CANAVERAL, Fla. -- Storm clouds move in over Launch Pad 39A at NASA's Kennedy Space Center in Florida, postponing the retraction of the pad's rotating service structure, which would reveal space shuttle Discovery. The structure provides weather protection and access to the shuttle while it awaits lift off on the pad. RSS "rollback," as it's called, will begin again after the lightning-producing clouds pass. Launch of Discovery on the STS-133 mission to the International Space Station is set for 3:29 p.m. on Nov. 4. During the 11-day mission, Discovery and its six crew members will deliver the Permanent Multipurpose Module, packed with supplies and critical spare parts, as well as Robonaut 2, to the orbiting laboratory. Discovery, which will fly its 39th mission, is scheduled to be retired following STS-133. This will be the 133rd Space Shuttle Program mission and the 35th shuttle voyage to the space station.