WASHINGTON : The US shuttle Discovery made a textbook docking late Sunday with the International Space Station where a total of 13 astronauts begin nine days together improving and supplying the orbiting outpost.

US space agency Nasa confirmed the docking procedure, which allows the seven-member Discovery crew to open a hatch and climb into the ISS to join their six fellow astronauts there, occured at 2354 GMT, about ten minutes ahead of schedule.

Commander Rick Sturckow guided the shuttle to a “smooth-as-silk” mating of the two vessels some 225 miles (362 kilometers) above the Atlantic ocean, said a commentator on Nasa TV.

“Both vehicles at free drift, all thrusts disabled,” he added.

The astronauts then began some 90 minutes of checks to complete on either side of the docking interface before opening the hatches.

As the shuttle sped toward the ISS, the astronauts conducted a routine inspection of Discovery’s heat shield by maneuvering a sensor on a robotic arm to look for possible damage.

Then a more comprehensive inspection was performed ahead of the docking with the ISS, with Sturckow guiding Discovery into a slow-motion backflip that allowed the station’s crew to snap hundreds of digital photographs of the heat shield from some 600 feet (183 meters) away to look for any damage that may have occurred during liftoff.

The inspections have been taking place on every shuttle mission since heat shield damage caused Columbia to explode as it returned to Earth in 2003, killing its seven astronauts.

Discovery’s seven astronauts — including one Swede — are delivering equipment for a new bedroom, a treadmill, a freezer, food and other supplies.

They will also be dropping off the newest member of the ISS team — US astronaut Nicole Stott, who will be taking over from engineer and fellow American Tim Kopra.

Kopra has been aboard the orbiting laboratory since July and is returning to Earth with the shuttle.

Discovery began its latest journey with the failure of one of two small steering jets that flank the orbiter nose after a leak, but NASA said the loss would have no impact on the shuttle’s flight or return to Earth.

The crew will close a manifold to isolate both jets and disable them from use for the remainder of the mission, said the National Aeronautics and Space Administration.

Discovery blasted off from Cape Canaveral, Florida, late Friday after its launch was delayed three times by bad weather and a valve problem.

The crew will be delivering to the station 6.8 tonnes of cargo transported in a pressurized module called Leonardo that was built by the Italian space agency.

Two astronauts from the team are scheduled to conduct three spacewalks of six-and-a-half hours each during the 13-day mission, the fourth of five planned for the shuttle program this year. The last is scheduled for November.

One of the key goals of the spacewalks is the replacement of an old liquid ammonia tank, which will be substituted with a new 800-kilogram (1,760-pound) replacement. The substance is used as a coolant.

The astronauts will also be retrieving experiment equipment from the exterior of the ISS and returning it to Earth for processing.

The freezer being delivered will store samples of blood, urine and other materials that will eventually be taken back to Earth for study on the effects of zero-gravity.

The COLBERT treadmill, named after popular US comedy talkshow host Stephen Colbert, will be the second aboard the ISS. Exercise is key for astronauts spending long periods of time in space, where zero-gravity can result in muscle atrophy.

The mission will be the 128th for the space shuttle program, and the 30th mission to the ISS.

Once the Discovery mission is complete, just six more shuttle flights remain before Nasa’s three shuttles are retired in September 2010.