Two of shuttle Endeavour’s spacewalkers ventured outside of the International Space Station to extend the reach of the station’s robotic crane and bolster its power supply.
Drew Feustel and Mike Fincke, Endeavour’s most experienced spacewalkers, completed an excursion that spanned nearly seven hours to get the station ready to operate after the shuttle program ends this summer.
It was the third of four spacewalks planned during Endeavour’s 16-day mission, the next-to-last in the U.S. space shuttle program. The fourth is scheduled for Friday, Reuters reports.
Feustel and Fincke accomplished their main goals — installing a fixture to allow the station’s robotic crane to move over to the Russian side of the $100 billion complex, and laying cables to route power from the U.S. solar array wings to the station’s Russian modules.
Over the three spacewalks, astronauts have contended with a series of challenges — a faulty spacesuit sensor that spurred ground controllers to cut the first spacewalk short and errant bolts that unexpectedly floated free during the second.
On Wednesday, Fincke got temporarily entangled in his safety tether, and Feustel struggled with an irritated eye.
“My right eye is stinging like crazy,” Feustel said. “The problem with tears in space is that they don’t fall off of your eye.”
Despite the setbacks, both astronauts were awestruck by the spectacular views of the Earth, 220 miles (355 km) below.
“There’s probably no better place to watch a … sunrise than from up here,” Feustel said as the station emerged into the daylight portion of its orbit over the coast of Mexico.
Endeavour and its six-member crew arrived at the station on May 18 for a 12-day servicing call, the next-to-last mission before NASA ends the space shuttle program.
The agency on Tuesday reaffirmed plans to build a new spaceship, called Orion, that can travel beyond the station’s orbit where the shuttles cannot go. A decision on what type of rocket will launch it is expected next month.
NASA is retiring its three-ship shuttle fleet due to high operating costs and to free up funds for new exploration initiatives to asteroids, the moon and eventually to Mars.
Russia already has picked up station crew taxi flights, and NASA hopes U.S. commercial companies will be offering similar services within about four years.
Endeavour is due back at the Kennedy Space Centre in Florida on June 1.
NASA’s final shuttle mission, a cargo run to the station aboard shuttle Atlantis, is slated to lift off on July 8.