Cape Canaveral, Fla. ? With a 4-inch gap in the space shuttle Atlantis’ heat-protecting blanket not appearing to be an urgent problem on Saturday, the crew members readied themselves for what NASA called a delicate ballet with the international space station.

Then the shuttle will enter a weeklong embrace today with the orbital outpost.

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, John Shannon, chairman of the mission management team, said at a news conference.

“It’s not a great deal of concern right now, but there’s a lot of work to be done,” Shannon said. “Other than that, the vehicle is very clean.”

NASA engineers want to study more photos of the torn blanket, which covers maneuvering engines at the tail of the shuttle, particularly images that were taken by cameras attached to the solid rocket boosters that separated from Atlantis more than two minutes into flight and then dropped into the Atlantic Ocean. The boosters are recovered by ships after each launch.