NASA has canceled the return of the space shuttle Atlantis to Earth on Friday due to bad weather at the Kennedy Space Center in Florida, the US space agency said. Atlantis could return on Saturday at 9:16 am (1916 PST) at the earliest, NASA said. Atlantis, which blasted off on May 11 with a crew of seven astronauts on a mission to repair the Hubble space telescope, had been scheduled to touch down Friday at 10:00 am (2000 PST).