Space shuttle Atlantis begins trip to launch pad

Space shuttle Atlantis began a slow trek to the launch pad early at Cape Canaveral, Florida, today.

It’s a major step towards a mission to resume construction of the international space station for the first time in three years.

The trip to the launch pad was delayed twice this week because of stormy weather.

The four-mile trip to the launch pad from the Vehicle Assembly Building started shortly after 1am local time (6am Irish time) and was expected to take under eight hours. Perched on a 131-foot-wide platform attached to four crawlers with eight tread-shoe tracks, the shuttle was unable to move faster than a mile per hour.

Atlantis has not flown since October 2002, and there has been no construction on the international space station since December 2002. During the 11-day mission, Atlantis’ six astronauts are scheduled to conduct three spacewalks and deliver and install giant solar arrays that power the space station.

The deadly Columbia accident in early 2003 halted all expansion of the orbiting space lab and forced a reduction in the crew size from three to two.

The crew size returned to three members last month after space shuttle Discovery delivered European Space Station astronaut Thomas Reiter to the international space station.

The window for launching Atlantis starts on August 27 and lasts until September 13, but Nasa managers are considering opening up the window a day earlier. Nasa managers are wary of launching the shuttle too late in the window since a Russian Soyuz vehicle with three crew members is scheduled to launch from Kazakhstan on a trip to the international space station in mid-September.

Atlantis’ launch will be the second of the year, and only the third shuttle mission since the Columbia disaster killed seven astronauts.