The culprit: a speeding piece of space junk.
The Canadian Space Agency and NASA said the 5 mm (0.20-inch) hole punched through a thermal blanket wrapped around the arm boom.
The armâ€™s performance was unaffected after what CSA officials called a â€œlucky strike.â€
Weâ€™ll never know what, exactly, was responsible for the damage. NASA estimates there are 100 million pieces of debris larger than 1 mm in low Earth orbit.
While the size of those objects is relatively small, their speed of up to 17,500 mph â€• more than eight times faster than an AR-15 bullet â€• means even a tiny bit of junk can cause significant damage. Plus, the space station itself is moving at about the same speed, so a head-on collision poses a significant risk.
A number of space shuttle windows, for example, had to be replaced due to damage caused by paint flecks in space.Â In 2016, a possible paint flake struck a window in the space stationâ€™s Cupola, gouging out a 7 mm chip that was documented by European Space Agency astronaut Tim Peake.
â€œI am often asked if the International Space Station is hit by space debris,â€ Peake said at the time. â€œYes â€“ this is the chip in one of our Cupola windows, glad it is quadruple glazed!â€
Of the 100 million pieces of space trash, NASA tracks roughly 23,000 pieces that are larger than a softball and capable of causing major damage.
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