Atlantis nears International Space Station

Bringing more than five tons of supplies and equipment, the space shuttle Atlantis closed in on the International Space Station early Sunday, on course for the shuttle program's 37th and final docking since the lab's assembly began in 1998.

The crew of the space shuttle Atlantis arrived in Florida on Monday for the last ever shuttle launch. Photo credit: William Harwood/CBS News

Atlantis took off on Friday after a cliffhanger countdown, putting on one last sky show for spectators jamming area roads and beaches to witness Nasa's 135th and final shuttle launch.

With commander Christopher Ferguson and pilot Douglas Hurley monitoring the computer-orchestrated countdown, Atlantis's three hydrogen-fueled main engines flashed to life at 120-millisecond intervals, followed 6.6 seconds later by ignition of the shuttle's twin-solid fuel boosters at 11:29:04am local time at Kennedy Space Center in Florida.

After inspecting the shuttle's heat shield and fine-tuning its approach, the astronauts set their sights on docking at the lab's forward port around 11:07am ET on Sunday. However, at around 6am, one of Atlantis's four general-purpose computers — GPC-3 — inadvertently shut itself down during a 'wake-up' procedure, and flight controllers told the crew to press ahead without it. As it turns out, GPC-3 experienced a similar shutdown during a flight in 2008.

"It turns out we have seen something like this fairly recently on (shuttle mission) STS-122," astronaut Steve Robinson radioed from Mission Control. "I don't know what you want to make of the common factors, but it was the same orbiter, the same GPC and the same MS-2." He was referring to mission specialist Rex Walheim, one of Atlantis's four current crew members.

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Nasa mission control commentator Rob Navias said the loss of one general-purpose computer would have no impact on rendezvous and docking.

"GPC-3 told itself to turn itself off, basically, at the time we were going into what is known as a set expansion for the rendezvous," he said. "This is when all the computers are brought up... in support of the rendezvous activities. The switch detent that this GPC runs under thought it went into a halt and shut itself down. It will not be put back into the set of GPCs until once we dock to the International Space Station, and likely will not be recovered until Monday morning."

The terminal phase of the two-day rendezvous was scheduled to begin at 8:29am local time with a rocket firing to begin closing the final eight nautical miles to the lab complex.

For more on this ZDNet UK-selected story, see Atlantis closes in on International Space Station on CBS News.