CAPE CANAVERAL, Florida – Two NASA astronauts completed the first spacewalk Friday of a mission to install a seven-windowed observation dome aboard the International Space Station.
A giant robot arm hoisted the massive Tranquility node and the cupola, which will provide spectacular panoramic views of Earth and help crew members monitor space walks and docking operations, from the shuttle Endeavour's payload bay onto the ISS.
The two spacewalkers then completed the first phase of work attaching the 2,600-cubic-foot (74-cubic-meter) addition to the orbiting space station, which was built for NASA by the European group Thales Alenia Space in their Turin factory.
US astronaut Bob Behnken and his British-born partner Nicholas Patrick completed the first spacewalk of the mission, a six-hour, 32-minute outer space task at 3:49 am (0849 GMT).
"The spacewalking pair finished all their assigned work and some get-ahead tasks," the US space agency said in a statement.
Behnken, the lead spacewalker for the mission, undertook his fourth spacewalk, while Patrick headed out for the first time.
The cupola can accommodate two crew members at a time and is equipped with portable workstations that can control station and robotic activities.
Six windows are arrayed along its sides and another on top, all protected against the impact of tiny meteorites.
Once the new room is in place, the space station will be 90 percent complete.
The mission, one of five scheduled for NASA's three shuttles before the program ends later this year after a 29-year run, comes as the US space agency reevaluates its future after President Barack Obama effectively abandoned its plan to send astronauts back to the moon by 2020.
Constrained by soaring deficits, Obama submitted a budget to Congress that encourages NASA to focus instead on developing commercial transport alternatives to ferry astronauts to the ISS after the shuttle program ends.
The ISS, a joint project involving 16 countries, has cost around 100 billion dollars, mostly funded by the United States.
Under Obama's new budget, the orbiting research station could see its life extended by five years until 2020.
© AFP 2015