A chip in a car window is quite bothersome, but if the crack is in one of the windows of the International Space Station (ISS) it goes from annoying to terrifying.
The above picture was taken by European Space Agency (ESA) astronaut Tim Peake, and it shows a 7-millimeter chip on one of the multi-layered windows of the Cupola module. It was created by a small fragment of space debris no more than a few microns across, maybe a paint flake or a metal fragment.
Strikes such as this pose no threat to the astronauts, though. The European-built Cupola windows, which afford fantastic views of Earth, are multi-layered like the rest of the station, shielding the crew from harm.
“I am often asked if the International Space Station is hit by space debris. Yes – this is the chip in one of our Cupola windows, glad it is quadruple glazed!” said Peake in a statement.
The Cupola module gives astronauts a stunning view of Earth. NASA
Although not threatening, this type of incident highlights the risk of space debris to both crew and technologies in space. This fragment was just one of over 170 million debris fragments of a size less than 1 centimeter (0.4 inches), which could easily disable a system on a satellite. There are at least 670,000 objects in space between 1 and 10 centimeters (0.4 to 4 inches), capable of penetrating the ISS’s shielding system. There are around 29,000 objects of 10 centimeters or larger that could easily destroy a spacecraft.
It might seem surprising the danger these small objects pose, but one needs to remember that they have a speed of about 8 kilometers per second (about 18,000 mph), almost four times faster than the fastest bullet.
“ESA is at the forefront of developing and implementing debris-mitigation guidelines, because the best way to avoid problems from orbital debris is not to cause them in the first place,” stated Holger Krag, Head of ESA’s Space Debris Office, in the statement.
“These guidelines are applied to all new missions flown by ESA, and include dumping fuel tanks and discharging batteries at the end of a mission, to avoid explosions, and ensuring that satellites reenter the atmosphere and safely burn up within 25 years of the end of their working lives.”