The Endeavour crew completes the final spacewalk on the space shuttle's final mission into space, NASA reports.
Astronauts Mike Fincke and Greg Chamitoff completed a seven-hour, 24-minute spacewalk at 7:39 a.m. on May 27, NASA reported.
The primary objectives for the spacewalk were accomplished, including stowing the 50-foot-long boom and adding a power and data grapple fixture to make it the Enhanced International Space Station Boom Assembly, available to extend the reach of the space station's robotic arm.
The mission marks the end of a long history of service for the Endeavour shuttle itself.
The final launch was delayed by two weeks as engineers battled to resolve an electrical problem that plagued the original launch dates.
Extensive work was needed to fix a faulty heater system in the engine compartment. The heaters keep fuel from freezing in the line, critical in preventing it from rupturing in the cold vacuum of space.
NASA replaced a distribution box that shorted out a circuit supplying power to heaters for the orbiter's hydraulics system.
The NASA space shuttle also took with it the $2bn Alpha Magnetic Spectrometer particle detector to the International Space Station.
The device is designed to give scientists their first detailed study of the electrically charged particles streaming through the universe.
It could also reshape modern understandings of the universe in a similar way that the Hubble Space Telescope pioneered new frontiers in astronomy.
The pictures painted by AMS, which was assembled at the CERN physics research center near Geneva, could bring to light the universe's so-called dark matter -- material that is so far unaccounted for but necessary to explain what is observable.
Endeavour is the second-to-last shuttle mission for the 30-year US program. Atlantis will mark the end to the program in in June and July.
NASA is winding down its space shuttle operations this summer as it tries to save money, which will leave American and European astronauts with only Russian rockets as options for going into space.
In February, the space shuttle Discovery, NASA's oldest and most travelled spacecraft, made its final voyage into space.
The country is focusing on inspiring 3rd part companies to put astronauts in orbit using privately run launch, transport and services companies.
NASA will now focus its resources on deep space exploration, such as potential landings on asteroids and, eventually, Mars.