The International Space Station’s robotic arm, Canadarm2, was hit by a piece of space junk. Fortunately, however, it appears to be just a flesh wound, and the arm has been released for nominal surgery while analysis of the strike continues.
NASA and Canadian Space Agency officials don’t know exactly when the arm was hit – or what hit it – but the damage was discovered during a routine inspection on May 12. The hole is quite small, about 5 mm (0.2 inches) in diameter.
Since the arm is still operational, the damage appears to be limited to a small section of the arm extension and the thermal blanket.
Canadarm2, one of the CSA’s key contributions to the ISS, has been an integral part of the station since it arrived on board in 2001. The arm is 17.6 meters long and 35 cm (14 inches) in diameter. Canadarm2 was significantly involved in the construction of the ISS and also put on spaceships.
The CSA said in a blog post that while the greatest possible precautions are being taken to reduce the risk of collisions with the ISS, impacts with tiny objects will occur. The culprit could have been a piece of natural space dust or rock, orbital debris from a satellite, or debris from a spent rocket. Orbital debris is tracked by the global Space Surveillance Network, which uses electro-optical, passive radio frequency (RF) and radar sensors.
A 2021 report by the U.S. Office of the General Inspector General on NASA’s efforts to mitigate the effects of orbital debris found that millions of orbital debris exist in low-earth orbit (LEO), at least 26,000 the size of a softball or greater that could “destroy a satellite on impact; over 500,000 the size of a marble big enough to damage spaceships or satellites; and over 100 million the size of a grain of salt that could pierce a spacesuit. “
In this image from October 23, 2016, the Canadarm2 robotic arm of the International Space Station (ISS) captures Orbital ATK’s Cygnus cargo space probe on its sixth mission to the station. Credits: NASA
In addition, the report said, the growing volume of orbital debris threatens the loss of important space-based applications used in everyday life, such as weather forecasting, telecommunications and global positioning systems, which rely on a stable space environment.
Last but not least, the recent hit on the Canadarm2 – which came from an object that was definitely not tracked – shows the potential dangers astronauts are exposed to during space walks. Imagine an object traveling at 27,350 km / h (17,000 mph) hits someone in a spacesuit.