CAPE CANAVERAL, Florida (AP) -- The space shuttle Atlantis is charging toward its Sunday rendezvous with the international space station, apparently unaffected by a small gap in its heat-protecting blanket.

Atlantis' seven astronauts spent much of Saturday on a mandatory inspection of the shuttle's delicate heat tiles, outer edges and blankets for problems similar to the kind that caused the fatal Columbia accident in 2003. As of Saturday afternoon, no glaring problems were reported.

But late Friday and early Saturday, the crew spent extra time using a robot arm to look at a gap in a thermal blanket on the left side of the shuttle.

The gap, about 4 inches by 6 inches, appears to have been caused by air lifting the corner of the blanket up, John Shannon, chairman of the mission management team, said at a news conference.