Atlantis astronauts made the fourth spacewalk on Sunday to fix the solar arrays. Pat Forrester and Steve Swanson spent six hours in the space to fix the mechanism that holds 115-foot solar arrays. Now they can rotate smoothly and track the sun. This was the main task of the spacecraft.

During the mission astronauts also installed US oxygen generation system and extended computer cable.

The mission launched on June 10th and was scheduled for eleven days. It aimed to install $367 million solar arrays at the International Space Center to generate power from sun rays.

The main aim of the astronauts is done, but the mission also had problems with Russian computer and caused troubles to the astronauts. Russian cosmonaut Fyodor Yurchikhin was engineering to fix the computer problem. Now it is working properly the second day, but Yurchikhin need to test the computer to make it clear if the spaceship can return home.

Russian computer is to control the spacecraft's orientation, so it is very important to make sure it works properly. Its failure has already delayed the mission for two days. The mission will complete on Tuesday and take astronauts back home, if the computer passes tests successfully. But if not, Atlantis will need more days for troubleshooting. For HULIQ.COM