Washington - Shuttle Atlantis was due to undock from the orbiting space station Wednesday for the final leg of a picture- perfect mission that included a proud father's birth announcement. The six Atlantis crew members said farewell Tuesday to their six colleagues who remain on the International Space Station, then slammed shut the hatches that divide the two spacecraft, NASA said.
Atlantis is to undock at 0954 GMT Wednesday for its two-day journey back to Earth. Landing is set for 1443 GMT Friday at Cape Canaveral, Florida.
Beyond three chore-heavy spacewalks, which accomplished more than had been expected, the most poignant - and rare - event of the mission has been the birth in Houston of a baby girl to US astronaut Randy Bresnik.
Bresnik's wife, Rebecca, gave birth hours after dad had completed a spacewalk on Saturday - a long-awaited event for the couple who had nearly given up on natural childbirth. The couple adopted a son, now 3, from Ukraine shortly before Rebecca became pregnant.
The event makes Bresnik the second astronaut to become a father while in space. The first was Michael Fincke in June 2004.
Atlantis lifted off as scheduled on November 16, without the weather or technical delays that have become common in the nearly three-decade-old shuttle programme.
The shuttle brought tons of extra supplies to the ISS, in anticipation of the heavy-lifting shuttles' final year in service in 2010. During the spacewalks, astronauts attached storage chambers for the 12,360 kilogrammes of spare parts delivered by Atlantis.
As the first of several flights devoted largely to delivering spare parts, this mission was laden with the highest-priority items.
The so-called Express Logistics Carriers contain a variety of crucial parts: gyroscopes that help keep the ISS at the proper altitude in space; an extra hand for the station's robotic arm; a gas tank for providing oxygen to the airlock during spacewalks; parts for the station's cooling system.
The retirement deadline of the shuttle is fast approaching, with just five more launches scheduled and one year left to go in the programme. Russia's Soyuz spacecraft will provide the sole transport for astronauts to and from the space station. Russia also has unmanned cargo vessels with limited lifting capacity.
NASA is at work on developing the next generation spacecraft with an eye on returning humans to the moon or travelling to Mars and beyond. Full support for the plans is still undecided by the Obama government and Congress.
If the programme goes forward, it would carry the crew atop a rocket in a configuration that recalls the Apollo moon shots and which engineers say is safer than the space shuttle design, following the explosion of the Columbia in 2003.
