NASA astronauts' spacewalk successful

Staff Reports
NASA astronauts' spacewalk successful

     Astronauts accomplish goals quickly during spacewalk.

      All pumps break sooner or later.  Anyone with a septic tank knows it. Anyone with a bicycle knows it. And the astronauts of the International Space Station know it.
       Four days before Christmas, two astronauts ventured outside of the station to begin the delicate process of replacing a pump the size of a refrigerator. Five and a half hours later, they returned to the relative security of the station after completing their work more swiftly than expected.
       Astronauts Rick Mastracchio and Mike Hopkins successfully ventured “out the door,” as NASA scientists put it. Hopkins was in the suit worn by Luca Parmitano, an Italian astronaut who nearly drowned when his helmet unexpectedly filled with water during a spacewalk in July. During Saturday's spacewalk, astronauts periodically examined the condition of their flight suits for problems.
      They wore an absorbent pad in the back of their helmets in the event of another leak. The suits were also equipped with a makeshift snorkel, just in case. 
      Astronaut Koichi Wakata, a robotics expert from Japan, operated the robotic arm that assisted in the spacewalk.
      NASA reported the pump problem Dec. 11. A flow-control valve in the starboard pump module, which enables a flow of ammonia to cool station systems, stopped working properly, creating a temperature drop in one of the two external cooling loops.
      The loops circulate ammonia outside the station to keep both internal and external equipment cool. At one point, small flecks of ammonia landed on Mastracchio’s suit. Officials thought it would not pose a problem – and would be baked off the suit in the sunlight.
      The astronauts are scheduled to do the repair work in two, or possibly three, sessions. Another spacewalk was scheduled for Dec. 23 -- but has been pushed back to Dec. 24. A third could be scheduled for Christmas Day, but given the progress, that may not be necessary.
     The space station is larger than a six-bedroom house, according to NASA. It has 8 miles of wire connecting its electrical system, travels 17,500 mph and is in orbit 200 miles over the Earth.


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