Space shuttle moved to Florida launch pad

The space shuttle Discovery is photographed at Launch Pad 39A at NASA's Kennedy Space Center, September 30, 2007. REUTERS/NASA/Handout

CAPE CANAVERAL, Florida (Reuters) - Workers at the Kennedy Space Center moved the space shuttle Discovery out to its ocean-side launch pad on Sunday in preparation for a construction mission to the International Space Station slated to begin in three weeks.

Riding atop an Apollo-era mobile transporter, Discovery was rolled out of the massive Vehicle Assembly Building shortly before 7 a.m. for the 3.5-mile trek to the launch pad. It arrived about six hours later.

NASA is aiming to launch the shuttle on October 23, but the schedule is tight with just two contingency days to spare. Discovery will be carrying a new connecting hub to the station so partner laboratories built by Europe and Japan can be attached to the outpost.

“We’d always like to have more (contingency days). But we feel comfortable with two and when we’re ready to go, we’ll go,” Discovery’s manager Stephanie Stilson told reporters at the launch site.

Discovery’s launch preparations have taken a bit longer than planned. Workers found a leaky seal in the shuttle’s right-side landing gear strut that had to be replaced, delaying its move to the launch pad.

If the shuttle crew can successfully install the new connecting node, the U.S. space agency should have a good shot at launching Europe’s long-delayed Columbus module in December.

NASA needs to fly at least 11 more mission to the station to finish assembly before the shuttle fleet is retired in 2010. The agency also plans two station resupply missions and a final servicing call to the Hubble Space Telescope.

The station, a $100 billion project of 16 nations, is a little more than 60 percent complete.