WASHINGTON: The space shuttle Atlantis blasts off Friday on the last mission of its 25-year career, taking astronauts to the International Space Station (ISS) one last time before becoming a museum piece.
The 32nd and final voyage for Atlantis, which first launched in 1985, will take six astronauts to the orbiting space research facility, delivering an integrated cargo carrier and a Russian-built mini research module.
Lift-off is scheduled for 1820 GMT from Kennedy Space Center near Cape Canaveral in Florida, weather-permitting.
A poignant moment for NASA as the US space agency counts down towards the end of an era in human spaceflight, Atlantis will be retired on its safe return home.
"The vehicle is in great shape… and from a Space Shuttle Program and ISS Program standpoint, we’re ready to launch Atlantis and get this mission under way," NASA launch manager Mike Moses said Wednesday.
His team gave Atlantis a unanimous "go" for liftoff on mission STS-132 and weather forecasts were 70 percent favorable, reflecting some concern over possible low cloud.
During a mission of almost 13 days, most of which will be spent moored to the ISS, Atlantis and the crew will deliver more than 12 tons of equipment, including power storage batteries, a communications antenna and a radiator.
The biggest single element being transported is the five-ton Rassver research module, or MRM-1, which will provide additional storage space and a new docking port for Russian Soyuz and Progress spacecraft.
The Rassver — dawn in Russian — which will be permanently attached to the bottom of the space station’s Zarya module, carries important hardware on its exterior including a radiator, airlock and a European robotic arm.
Three spacewalks of six-and-a-half hours each are scheduled during the mission, notably to install new batteries and a communications antenna on the space station.
When the mission is complete, only two more shuttle launches remain — one each for Discovery and Endeavour — before the aging fleet is mothballed at the end of the year.
NASA late last month pushed back to November the launch of the shuttle Endeavour to modify an experiment module that is to be attached to the orbiting outpost.
It had been scheduled to lift off July 29 but will now launch "no earlier than mid-November 2010" so that scientists can upgrade a magnet in the Alpha Magnetic Spectrometer program to a longer-lasting device.
The rescheduling did not affect the launch of Atlantis but the move
means Endeavour now replaces Discovery — set for a September 16 mission — as the last ever shuttle launch.
Once the three shuttles are retired, the United States will rely on Russia to take astronauts to the station aboard three-seater Soyuz spacecraft until a new fleet of commercial space taxis is operational.
President Barack Obama effectively abandoned in February plans laid down by his predecessor George W. Bush to send astronauts back to the moon by 2020 and perhaps on to Mars with a new generation of rocket and spacecraft.
Constrained by soaring deficits, Obama submitted a budget to Congress that encouraged NASA to focus instead on developing commercial transport alternatives to ferry astronauts to the ISS after the shuttle program ends.
Nonetheless, Obama set a bold new course in April for the future of US space travel, laying out a vision to send American astronauts into Mars orbit within the next three decades.
He envisaged the design of a new spacecraft by 2025 for human travel deep into space and said he believed missions to asteroids and to orbit Mars by the mid-1930s were achievable.
By the time the final three missions are complete, the space shuttles — characterized by NASA as the most advanced machines ever built — will have flown 134 missions into orbit.
The ISS, a joint project involving 16 countries, has cost around $100 billion, mostly funded by the United States.