The space shuttle Discovery’s landing has been pushed back to Tuesday because of low clouds above Florida’s Cape Canaveral on Monday. All three primary landing sites will be activated on Tuesday, so the shuttle can potentially land at Cape Canaveral, Edwards Air Force Base in California, or White Sands Space Harbor in New Mexico. Weather forecasters are expecting similar weather in Florida for Tuesday, so it’s likely Discovery will have to use an alternative site. The first landing attempt will be at 0907 UTC (5:07 am EDT).