by Theresa Machemer/Smithsonianmag.com
On May 12, a routine inspection of a robotic arm on the International Space Station revealed a five-millimeter-wide hole in its thermal covering.
According to a statement by the Canadian Space Agency, the robotic arm known as Canadarm2 collided with a small piece of orbital debris—also known as space junk. The exact object that punched a hole in the robotic arm is unknown. Because the object only damaged the thermal blanket of the arm boom, and not a piece of electronics or machinery, the arm will continue to carry out its planned missions, Ashley Strickland reports for CNN.
“The threat of collisions is taken very seriously. NASA has a long-standing set of guidelines to ensure the safety of Station crew,” says the Canadian Space Agency in its statement. “The safety of astronauts on board the orbiting laboratory remains the top priority of all Station partners.”
Earth is surrounded by orbiting debris: about 8,000 metric tons of it, as of January 1, 2020, reported Elizabeth Gamillo for Smithsonian in January. The U.S. Space Surveillance Network tracks about 23,000 objects that are larger than the size of a softball, writes Elizabeth Howell for Space.com. But there are tens of millions of pieces of debris smaller than a centimeter wide that are too small to be monitored.