According to NASA, orbital debris smaller than one centimeter has reached an army of 100 million. At this size, they’re difficult to track, and can still inflict damage on passing spacecraft.

“Debris this small has the potential to damage exposed thermal protection systems, spacesuits, windows, and unshielded sensitive equipment,” says Joseph Hamilton, principal investigator of the Space Debris Sensor (SDS) project. “On the space station, it can create sharp edges on handholds along the path of spacewalkers, which can also cause damage to the suits.”

The International Space Station (ISS) has a few tricks up its sleeve to deal with the onslaught of debris. For large objects, ground control systems employ tracking mechanisms. In certain circumstances, ISS thrusters can safely relocate the station.

Orbital debris shields handle pieces smaller than 1.5 centimeters. Now, the Space Debris Sensor will join the space junk fight.

The SDS will be active for the next two to three years, acting as a calibrated impact sensor situated on the station’s exterior. It will record the time and scale of small space particle impacts between .05 mm to .5 mm. The entire design includes a resistive grid sensor system, sensor-embedded backstop, dual-layer thin films, and an acoustic sensor system.

All this equipment will allow the SDS to provide real-time impact detection. The dual-layer thin films first provide the time, location, and speed of the space debris. The sensor-embedded backstop acts as the final layer, recording the particle’s density.

“The backstop has sensors to measure how hard it is hit to estimate the kinetic energy of the impacting object,” says Hamilton. “By combining this with velocity and size measurements from the first two layers, we hope to calculate the density of the object.”

The research team hopes the SDS data can locate the entire orbital debris population. This will help in the preparation and placement of future sensor systems beyond the ISS in more high-risk areas.