Space Mechanics
Endeavor astronauts complete fourth spacewalk, have mission extended
Astronaut Steve Bowen participates in the mission's third scheduled spacewalk as construction and maintenance continue on the International Space Station (ISS). (Photo: NASA)
Just call these astronauts grease monkeys.
High above the Earth—225 miles high, to be exact—two Endeavor crewmembers spent six hours Monday passing a grease gun back and forth. They were lubing up a damaged joint on the station's solar wings during the fourth and final space walk of the Endeavor's mission at the International Space Station (ISS).
Astronauts spent nearly a week cleaning and greasing the damaged joint. It allows the space station's solar panels to point at the sun. The repair work took so long due to an equipment shortage.
During the first space walk of the mission, astronaut Heidemarie Stefanyshyn-Piper was trying to clean a grease gun. She was also holding on to her tool bag. She didn't secure the bag, and it slipped out of her hands. She tried to grab it, but all she could do was watch it float away. The bag held $100,000 in equipment.
"There's the psychological thing of knowing that we made a mistake and having to live through that," Stefanyshyn-Piper told the news agency the Associated Press. "It was hardest coming back in and having to face everybody else."
The repair work happened inside the ISS as well as outside.
Part of Endeavor's mission is to upgrade the living quarters on the 10-year-old station. Right now, there's room for three astronauts. NASA wants to add space for three more. An important part of that growth is the installation of a new water filtration system. It turns condensation and urine into drinkable water for the astronauts.
"It's just the water that's taken out," ISS commander Mike Fincke said. "It's really clean and purified water. In fact, it's probably more pure than most people's tap water. So I'm not afraid to drink it."
So far, the tap on the ISS has been running dry.
During each test, the station's computers detected a mechanical problem with the filtration system and shut if off. The longest it has run is three hours.
The filter takes urine from the astronauts and distills it in a partial space vacuum that boils the water in the urine. Then, that distilled wastewater is put through a mini-treatment plant that removes dirt and other contaminants. After that, the water gets put through filters and is cleaned. At the end, salts are put into the water to give it some taste.
Getting the system to work is critical for the future of the station and space travel. The filter is vital for the expansion of the ISS from a station that can house three people into one that can shelter six. At the same time, NASA believes that this kind of water filtering system will make deep-space exploration easier.
Until things start working correctly, astronauts can't drink any of this recycled water. It needs to be tested first on Earth to make sure it's clean enough to drink.
To try and fix the problem, NASA has extended Endeavor's mission an extra day. This means the astronauts will spend Thanksgiving on the ISS with the station's crew. Endeavor will depart the ISS on Friday and return to Earth Sunday.
Discover more about the final frontier in the News From Outer Space Special Report!
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 | The experiments astronauts conduct in space can impact life on Earth. The new water filtration system being installed on the International Space Station, for example, could change how we get our water. What ideas for other eco-experiments do you have? What would you research in space if you were an astronaut? Tell us what you think on the Scholastic News Online Blog! | |
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