Sometimes NASA astronauts, as well as Santa Claus, have to work on Christmas Eve, if urgent repairs are needed and a spacewalk is called for at the International Space Station. Such was the case on Tuesday, December 24, as two astronauts went out on a spacewalk to repair the cooling system of the ISS.
The spacewalk was the second Christmas Eve one in the history of NASA, and it was also the second one within the space of four days for NASA astronauts Michael Hopkins and Rick Mastracchio.
Making repairs to the cooling system of the International Space Station were critically necessary, because when the line went out on December 11, all nonessential equipment had to be shut down. Also, several scientific experiments had to be suspended. The pump module removes excess heat and sends it out into the vacuum of space.
During the lengthy 7 and a half hour spacewalk 260 miles above the Earth, Hopkins and Mastracchio had to install a new ammonia pump after they removed the old, faulty one last Saturday. The ammonia pump had a bad valve that needed to be replaced. The pump should be fully activated and working with the rest of the cooling system sometime on December 25, Christmas Day.
NASA scientists don’t know why the old ammonia pump needed to be replaced, as it had just been installed three years ago by another team of astronauts. They hope to examine it at some point in the future to learn why it failed.
That 2010 repair took a total of three spacewalks to accomplish. It took that many spacewalks because it was more difficult to remove the pressurized ammonia fluid lines than the astronauts had realized it might be.
The Christmas Eve spacewalk had been originally scheduled for Monday, but Mastracchio accidentally hit a water switch in the air lock at the end of the Saturday spacewalk, and water got into his spacesuit making it unusable this week and forcing him to switch to another spacesuit for Tuesday’s spacewalk.
NASA commentator Rob Navias told viewers on TV that since it’s Christmas Eve, “in this holiday way of giving, we’re giving you a spacewalk today.” He added that Mike Hopkins was “taking a special sleigh ride on this Christmas Eve.” The desks of Mission Control at the Johnson Space Center in Houston were decked out for the holiday, with Santa dolls, tabletop Christmas trees, and other decorations.
Astronaut Michael Hopkins wished everybody a “Merry Christmas” and added that though it took a couple of weeks “to get her done” they finally finished up the repairs by installing the new pump during the rare Christmas Eve spacewalk.
If you were wondering when the first NASA Christmas Eve spacewalk occurred and why, it happened in 1999. That eventful spacewalk was necessary in order to repair the Hubble Space Telescope.
On Friday, a Moscow-led spacewalk by two Russian astronauts will install new experiments and cameras outside the International Space Station.
The Christmas Eve spacewalk proves that Santa Claus isn’t the only one who works on Christmas Eve. Sometimes NASA astronauts have to work then, also, in cases like when repairs to the International Space Station are needed.
Written by: Douglas Cobb