The space shuttle Atlantis has docked with the International Space Station, completing a crucial step in its 11-day mission to the orbiting outpost.
Commander Brent Jett first had to flip the shuttle on its back so ISS crew could scan its underside for damage.
Then, he slowly aligned the spacecraft with the docking port and achieved a perfect link-up at 1048 GMT (0648 EDT).
The astronauts got a warm welcome from the ISS crew after opening the hatch separating their joined spacecraft.
"Houston station, capture confirmed," Commander Jett radioed back to Earth after the docking manoeuvre was completed.
The 11-day mission aims to double the station's energy-generating capacity.
Nasa says that some debris from the fuel tank did hit the orbiter during its launch, but no damage was detected from ground observations.
"At this point, the mission has been going along well," said the shuttle programme's deputy manager John Shannon.
"We saw no debris at all coming off during our critical period; Atlantis looks great."
Three possible impacts on the shuttle were detected, two from insulation foam and a third from ice; but all occurred several minutes after launch when Atlantis was already travelling through the thinner air of the upper atmosphere, which Nasa says is less likely to result in damage.
Saturday's launch was just the third shuttle mission since the orbiter Columbia broke up on re-entry after being damaged by launch debris in 2003.
ISS: ORBITING OUTPOST
Construction work has been on hold for four years
16 nations contribute to the ISS, including the US, Russia, Japan, Canada, Brazil and European Space Agency states
The ISS will eventually be the size of a football field
The period following docking will, says Nasa, be one of the most complex and busy in shuttle history.
The first task is to transfer and then fit the P3/P4 truss, a 17-tonne segment of the space station's "backbone" that includes a huge set of solar arrays and a giant rotary joint to allow them to track the Sun.
The arrays will be the second of four sets, and will span 73m (240ft) when fully extended.
Once fitted, they will effectively double the station's current ability to generate power from sunlight.
Astronauts Joe Tanner and Heidemarie Stefanyshyn-Piper then plan an "overnight camp out" in the airlock in preparation for the first of three spacewalks.