The crew of the U.S. space shuttle Atlantis has been welcomed aboard the International Space Station after docking successfully with the space station, high above Earth's surface.
As they approached the space station for Sunday's docking, Atlantis's commander used steering rockets to flip the shuttle onto its back, allowing astronauts aboard the orbital laboratory to take close-up photos of the shuttle's heat shield covering the bottom of the fuselage. The pictures were relayed to NASA engineers on the ground, for analysis.
Any damage to key portions of the heat shield could be a serious problem, since that protects the shuttle and its crew from burning up when the huge spacecraft re-enters Earth's atmosphere.
Four years ago, damage to heat-shielding tiles incinerated the shuttle Columbia as returned to Earth, and killed all seven astronauts aboard.
Shortly after Atlantis was launched on Friday, a gap about 10 centimeters wide was spotted in a thermal blanket - another part of the heat shield. Experts say this is not a serious concern, because the gap is in an area not exposed to the most extreme heat during re-entry.
While docked at the space station, Atlantis astronauts will install a new set of solar electricity panels and continue construction and expansion of the orbiting laboratory. There also will be a crew change, with Atlantis astronaut Clayton Anderson taking the place of fellow American Sunita Williams. She has completed a six-month stay in orbit and will return home after Atlantis' 11-day mission.