Shuttle Discovery Docks at Space Station
STS-120 commander Pamela Melroy, NASA's second female shuttle commander, guides Discovery in to an Oct. 25, 2007 docking at the International Space Station (ISS), where Peggy Whitson - the station's first female commander - and her crew awaited the orbiter's arrival.
Credit: NASA TV.

This story was updated at 10:45 a.m. EDT

HOUSTON - The space shuttle Discovery arrived at the International Space Station (ISS) early Thursday with its seven-astronaut crew set for the challenging task of adding a new orbital room onto the high-flying laboratory.

After a two-day orbital chase, Discovery and its STS-120 crew docked at the ISS at 8:40 a.m. EDT (1240 GMT), with shuttle commander Pamela Melroy parking the 100-ton spacecraft at the tip of the station?s U.S. Destiny laboratory. Inside the space station, Expedition 16 commander Peggy Whitson - the outpost?s first female commander - rang the ship?s bell as both spacecraft crews let loose celebratory cheers.

?Discovery arriving,? Whitson said as the two spacecraft docked high above the southern Pacific Ocea n.

The orbital rendezvous marks the first time two spacecraft have docked with female astronauts in command. Melroy, Whitson and their crews opened the hatches between their two spacecraft at 10:39 a.m. EDT (1439 GMT), trading hearty hugs and laughs before posing for photographs.

?We?re welcoming them with open arms, and the towels are all clean and laid out,? said Expedition 16 flight engineer Clayton Anderson of the STS-120 crew?s arrival.

The joint shuttle-ISS crew will spend a busy 10 days together to add a new pressurized module, swap out one station crewmember and move a 17.5-ton solar power tower during five planned spacewalks.

Anderson, a NASA astronaut, is completing a five-month mission aboard the ISS and will return to Earth aboard Discovery when the shuttle departs on Nov. 4. His replacement, fellow U.S. spaceflyer Daniel Tani, will officially join the ISS crew later today once his Russian-built seat liner is moved into the Soyuz TMA-11 spacecraft berthed the station.

?It?s moving day for me and I can?t wait to settle in my new home,? said Tani, who awoke to the song ?Dancing in the Moonlight? piped in from Mission Control here at the Johnson Space Center.

Before Discovery docked at the ISS, Melroy guided the spacecraft through an orbital back flip about 600 feet (182 meters) below the space station. Known as the Rendezvous Pitch Maneuver, the nine-minute spacecraft somersault allowed Anderson and fellow Expedition 16 flight engineer Yuri Malenchenko to take high-resolution photographs of the heat-resistant tiles lining Discovery?s underbelly.

The images, combined with data from a Wednesday scan of the heat-resistant panels along Discovery?s wing edges and nose cap, will allow engineers on Earth to determine the health of the shuttle?s heat shield. An early analysis of the earlier inspection and images of Discovery?s external fuel tank has given mission managers confidence that the shuttle?s heat shield is in good shape, though a definitive answer is expected by the end of the week. NASA has kept a close eye on shuttle heat shield integrity and fuel tank debris during liftoff since the 2003 Columbia accident.

With Discovery successfully docked at the ISS, a busy mission of orbital construction is set to begin.

Tucked in the shuttle?s payload bay is Harmony, a nearly 16-ton module that will serve as the anchor for future international laboratories at the space station. Discovery?s STS-120 crew will attach the Italian-built Harmony node to a temporary berth on the station?s Unity node during the first of five planned spacewalks during their planned 14-day mission. It will be moved to the front of the Destiny module once Discovery undocks.

The shuttle astronauts will also move a massive solar array segment from its mast-like perch atop the ISS to a permanent spot on the port-most edge of the station?s backbone-like main truss.

?Everyone here is just ecstatic,? STS-120 mission specialist Scott Parazynski told Mission Control. ?We?re so fired up to be here and are looking forward to the next several days shared with the station crew.?

NASA is broadcasting Discovery's STS-120 launch and mission operations live on NASA. Click here for mission updates and NASA TV from SPACE.com.

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