NASA’s mission on the International Space Station continues with the third scheduled spacewalk. The two astronauts involved have already begun their tasks in what was described as the hardest part of their entire assignment. The spacewalk is expected to take more than seven hours and aims at completing the repair actions on the gummed-up joint by cleaning and lubricating the solar wing-rotating joint and also instal the new bearings.

During a news conference held yesterday, astronaut Heidemarie Stefanyshyn-Piper confirmed that this task will be a bit harder than the rest. "It looks like it's going to be challenging," she said, as quoted by the Associated Press, adding that "We have a lot of work to do."

So far the mission came across two problems: one with the lost tool bag, with $100,000 worth of equipment, which drifted away into space and the second involves the $154 million recycling system which shut down yesterday for a seconf time without any aparent reason. The system was designed to turn the astronauts’ urine into drinking water and this period was supposed to be used for tests, in order to make sure that everything works fine. The space shuttle Endeavour, on its return, should bring back samples of processed urine for careful investigations but so far the crew was unable to use the expensive technology. The reason why this is considered a very important issue is because the system is considered crucial in the agency’s plans for next year to enlarge the station’s crew from three astronauts to six.