STS-126 mission astronauts Heidemarie Stefanyshyn-Piper and Steve Bowen completed their third repair mission on the International Space Station after a spacewalk of almost seven hours. The two continued the work began in the previous spacewalks, by carrying on with the cleaning of the station’s SARJ, but also with the removal and replacement of the remaining trundle bearing assemblies.

The astronauts will end their repair mission outside the International Space Station on the fourth spacewalk which is going to take place on Monday, this time conducted by Shane Kimbrough and Steve Bowen. The astronauts will continue lubrication and servicing of the SARJ.

While Stefanyshyn-Piper and Bower were working on the outside, the other members of the crew worked on setting up the Water Recovery System, and took samples of the Water Processor Assembly. According to NASA, ground controller at Houston will examine the data from the Urine Processor Assembly to establish whether it continues to experience errors.

The new regenerative environmental control and life support system will give the station the ability to recycle urine and the condensation that the crew breathes into the air into pure water that can be used for drinking or to cool the station’s systems.

Inside the station, astronauts have also been working on expanding the capacity of the International Space Station from three-bedroom one bed-room residence for three astronauts to a five-bedroom two-bath residence for six astronauts.

NASA believes expanding the number of astronauts on the International Space Station is an important step toward using the station to its full capacity, as well as making it less dependent on the space shuttle.