*Three spacewalks planned during shuttle’s visit
*Discovery astronaut Nicole Stott to join station crew
*Shuttle delivering more than 7 tons of gear for outpost
By Irene Klotz
CAPE CANAVERAL, Fla., Aug 30 (Reuters) - U.S. space shuttle Discovery arrived at the International Space Station on Sunday with food, equipment and new lab gear for the orbital outpost.
After nearly two days of traveling following its launch late Friday night, Discovery reached the Space Station at 8:54 p.m. EDT (0054 GMT Monday) as it sailed 225 miles (362 km) over the Atlantic.
"The entire rendezvous and docking was smooth as silk," said NASA mission commentator Rob Navias.
During their nine-day visit, the Discovery astronauts plan to unload more than seven tons of gear packed aboard the shuttle and conduct three spacewalks to help ready the $100 billion outpost for full-time science operations.
NASA hopes to complete the station, a $100 billion project of 16 countries, by the end of next year after six more shuttle flights. Construction began in December 1998.
The first spacewalk, scheduled for Tuesday, will be to replace a tank of ammonia coolant and retrieve two European science experiments that will be coming back to Earth for analysis.
Nicole Stott, a rookie astronaut who will be transferring to the station crew, will perform the spacewalk together with astronaut Danny Olivas.
Stott is the last station crewmember to launch aboard the shuttle. NASA is turning over station crew transport to Russia while it studies proposals from aspiring U.S. commercial carriers.
Discovery’s cargo includes new laboratory gear for science experiments and a second freezer to store samples until they can be transported back to Earth.
Also aboard is a $5 million treadmill named after Comedy Central television host Stephen Colbert, who won naming rights to the station’s final module after fans swarmed a NASA publicity campaign.
"ASTRONAUT ICE CREAM"
The U.S. space agency chose the name Tranquility for the last connecting hub and offered up COLBERT -- an acronym for Combined Operational Load Bearing External Resistance Treadmill -- as a consolation prize.
"Let’s face it, being weightless is mostly just a desperate bid to get away from that bathroom scale every morning," Colbert joked in a video message to NASA. "You guys and gals are ambassadors to the universe. Don’t make us look bad. Put down the astronaut ice cream, tubby."
NASA took the ribbing in stride, though it considers exercise a crucial part of the station crew’s day. Resident astronauts spend about two hours a day exercising to help offset bone loss, muscle wasting and other adverse effects of weightlessness.
Scientists hope to get a better understanding of the mechanisms underlying bone loss in space, which is similar to osteoporosis, when a half-dozen mice aboard Discovery return from a three-month stay aboard the space station. Half have been laced with an extra gene tied to bone formation. The other three are unaltered.
Before linking up with the station, Discovery commander Rick Sturckow backflipped the shuttle so astronauts aboard the outpost could take pictures of Discovery’s heat shield.
The images are part of post-Columbia safety procedures to assure the shuttle was not damaged by debris during its climb to orbit. Columbia was hit by a suitcase-size chunk of foam that fell off its fuel tank during liftoff. The shuttle broke apart, killing the seven astronauts aboard, as it flew through the atmosphere for landing.
Preliminary assessments show Discovery arrived in orbit with no obvious damage, said LeRoy Cain, head of NASA’s mission management team.
"Overall, it looked like a very clean ascent," Cain told reporters.
Discovery is due back at the Kennedy Space Center in Florida on Sept. 10. (Editing by Tom Brown and Paul Simao)