This computer generated clip shows space debris in motion in low Earth orbit that is currently being tracked, as of January 1, 2019. Approximately 95% of the objects in this illustration are orbital debris, not functional satellites. [via NASA]

By Stephanie Dwilson | 2025-12-25

The millions of tiny fragments of space debris swarming in low Earth orbit (LEO) pose a growing threat to satellites, space operations and even crewed missions.

But traditional ground-based systems aren’t prepared to track them.

Though ground-based systems can reliably track objects 10 centimeters or larger in size, countless smaller pieces of debris are effectively undetectable.

NASA estimates there are more than one hundred million objects sized one millimeter or smaller in Earth’s orbit.

The European Space Agency's 2025 Space Environment Report estimates there are 140 million untracked space debris objects measuring one millimeter to one centimeter.

Although micro-fragments may seem innocuous, they can pose extreme dangers when traveling fast in space, as these tiny fragments can have an outsize impact when they collide with spacecraft.

And more micro-debris is being created all the time, as governments and private space companies accelerate the pace of space launches.

To address this burgeoning problem, organizations are working hard to create next-generation space technologies that can identify and track micro-debris.

Up-and-coming detection systems could enable real-time detection of minuscule space fragments, improve collision risk modeling, enhance adaptive shielding, and strengthen space traffic management.

Demand for micro-debris detection

US Space Force (USSF) Col. Nick Hague has logged 374 days in space and 25 hours and 56 minutes of time in four spacewalks.

Earlier this year, he offered an example of how micro-debris can impact operations on the International Space Station (ISS).

"It’s the little things that are maybe the size of a grain of sand, that drill themselves into an aluminum railing that you’re going to grab onto with a rubber glove," he said.

"And the aluminum’s got all these sharp edges so you can’t grab it because you’ll tear your glove, your suit will leak and then you’ll have to abort the EVA (extra-vehicular activity)."

"So imagine: six hours out there, you’re looking at every place you grab, making sure you don’t grab something you’re not supposed to. Those impacts are all over the outside of the space station."

The ISS is just one example of why the demand for precise space debris protection and tracking is rising, with advanced radar detection increasingly seen as critical for sustainable orbital operations.

USSF and NASA are each focusing on space domain awareness (SDA), which includes debris mitigation, but each come at the issue with different priorities.

USSF seeks to protect assets and deter conflict, while NASA integrates SDA with planetary defense, scientific exploration and safety.

Satellite operators such as SpaceX and Amazon Leo (formerly Project Kuiper) are facing increasing regulatory scrutiny connected to congestion in space.

Next-generation technology

One type of next generation radar technology that could make a significant difference is mmWave radar, able to detect millimeter-sized space debris, developed by the UK-based engineering and design company Plextek.

This radar is more accurate than traditional microwave length radar and is less costly than Light Detection and Ranging (LiDAR), which is considered the gold standard for functions such as high-precision 3D mapping and terrain modeling.

According to Plextek, this new radar system is ideal for space applications for a number of reasons, including improved visibility.

Because its wavelength is longer than LiDAR, sub-mm sized dust particles don’t obscure its view, enabling it to perform better in conditions where visibility is impaired.

Additionally, mmWave radar is not affected by the sun, which can interfere with LiDAR because its wavelengths are in the infrared spectrum. This means mmWave radar is more flexible, able to operate in sunlight or darkness.

Millimeter-wave radar may ultimately be able to help detect, map and track micro fragments in space.

Because mmWave systems are about the size of a human hand, they potentially could be used within large satellite constellations to map micro-debris.

Mapping these tiny fragments would be a huge step forward for the space industry.

"At the moment, ESA and NASA only have theoretical models for this type of debris," Plextek commercial lead Richard Jacklin said in a statement.

"They don’t have enough data to give them an accurate picture of what the debris fields look like at different altitudes in low Earth orbit."