By DPA,
Washington : Two space shuttle Endeavour astronauts on Monday began the last of four scheduled spacewalks at 1.24 p.m. (1824 GMT) to work on joints on the solar panels that power the International Space Station (ISS).
In the six-and-a-half-hour spacewalk, astronauts Shane Kimbrough and Steve Bowen were to complete the installation of trundle-bearing assemblies on the starboard Solar Alpha Rotary Joint (SARJ), which has occupied much of the previous three spacewalks during the current Endeavour mission.
The astronauts were also to clean and lubricate the port SARJ that has been working fine, install a camera and attach a global positioning system antenna on the Japanese Experiment Module Pressurized Section.
The US space agency NASA could extend Endeavour’s 15-day mission by one day to deal with problems that have cropped up with a urine recycling system, which is designed to turn waste into drinkable water.
Sunday, astronauts aboard the ISS worked on the recycling system, which has a problem with a centrifuge on a distillation component of the urine processor assembly and would shut down during tests before it could complete its task.
NASA scientists on the ground were to continue troubleshooting and hoped to get the system up and running before the Endeavour is due to leave the ISS Thursday.