The Biggest Sources of Space Junk Falling to Earth and Still in Orbit
In 1957, the Soviet Union made history by launching Sputnik, the world’s first artificial satellite. With that era-defining launch, the Soviets also made a second piece of history: the creation of the world’s first piece of space junk.
Since that day, over 15,000 satellites have been successfully launched into orbit, with 10,000 of these still active and present. These satellites, along with spent rocket stages and other objects, now represent some of the 32,000 tracked pieces of space debris larger than 10 cm. These represent only a fraction of the 131 million untraceable smaller parts of space junk that now pollute low Earth orbit (LEO).
Space junk has the potential to cause collisions with active satellites and even the International Space Station (ISS). The increasing clutter in orbit also poses risks to future space missions in the long term, as access will become more limited if current space junk trends continue.
Because of this, Blueshift has turned its attention to the growing challenge of orbital debris. Using orbital surveillance records from the U.S. Department of Defense’s Space-Track.org, which monitors all trackable objects measuring 10 cm or larger, we analyzed the patterns and trends shaping Earth’s near-space environment.
Our study reviewed every year of available Space-Track data, then focused on the past decade (2015–2024) to examine key measures: orbital decays, active payload launches, and cataloged debris. This approach allowed us to pinpoint which entities, including national space agencies, commercial operators, and joint international missions, have seen the most debris re-enter Earth’s atmosphere and which continue to hold the largest debris loads in orbit.
While our findings focus on tracked objects, it is important to note that the true scale of the debris problem is far greater. NASA and ESA estimate a vast number of smaller, untracked fragments remain an undetected and invisible threat to satellites, missions, and the long-term sustainability of space exploration.
The junk that fell to Earth: Three countries responsible for 90% of falling space debris
Russia, the United States, and China are responsible for the vast majority of space junk that currently resides in orbit.
Over the last decade, these three countries alone have contributed to more than 90% of falling space junk, as well as to the majority of debris still in orbit. Of these countries, Russia is the biggest culprit, with 3,162 pieces of falling space junk in the last decade, more than double that of the United States and China, which have been responsible for 1,332 and 1,254 pieces respectively.
With space exploration being one of the defining legacies of the USSR, it is unsurprising that Russia continues to be at the forefront of the cosmos. Similarly, the United States’ history in the field, along with its rapidly growing private space enterprises like SpaceX, leaves it well placed for space junk responsibility. China’s rapid rise over the last half century has led to expansion in land, sea, and now space.
Blueshift focuses on using cutting-edge technology to protect mission-critical space infrastructure in the most extreme conditions. Understanding how much space debris is re-entering the atmosphere at present, as well as in both the near and long term, has implications for planning future space travel.
Although at present any danger posed by space debris is typically related to other orbiting objects, this may change as space becomes more cluttered. With more countries and organizations sending up satellites and creating space junk in the process, collisions and debris falling to Earth, potentially in populated areas, could become a serious issue.
Clean up after yourself: Russia’s space debris falls more than any other nation
There have been a number of experiments relating to space junk cleanup, such as those run during the RemoveDEBRIS project to simulate different methods of debris removal. These methods include everything from space lasers and debris recycling to using nets and dragsails.
Creating space junk is something every spacefaring nation has contributed to. Cleaning it up, however, appears to be a lower priority. Russia is the guiltiest in this regard, relying on natural atmospheric decay, the process by which Earth’s upper atmosphere drags orbiting debris downward causing it to burn up on re-entry, to removing unwanted debris. This timeframe for this process varies, from a few years, to decades to centuries, depending on the size of the space junk in question. A major reason for this reliance on atmospheric decay is the potential expense of space cleanup operations. Although this is also a problem for the United States and China, it affects Russia the most because it has the most unstable economy of the three. Russia is also under intense sanctions due to the war in Ukraine. These sanctions have not only impacted Russia economically but have also restricted access to important space technology and material parts. As long as these sanctions remain, it is unlikely that Russia will move to prioritizing space junk cleanup.
Despite Russia, the United States, and China’s cosmic dominance, it is actually France that has the highest percentage, at 87%, of its space junk remaining in orbit. Alongside this fact it should be noted that France has launched significantly less into orbit than the “big three” have. For context, 533 pieces of French space junk remain in orbit compared to 5,217 pieces of Russian material and 4,730 pieces of Chinese material.
Is the space age here? Payload launches surge exponentially over the last decade
Over the past 10 years, the United States and China especially have rapidly increased their number of payload launches per year.
For the United States, this represents an increase of nearly 900% compared to the previous decade. Although government-funded organizations such as NASA have certainly played a role, the biggest reason for this increase is the private sector. Elon Musk’s SpaceX is the most prominent name in this regard. The company’s Falcon 9 rockets have been used to launch over 8,000 Starlink satellites into orbit. The increased privatization and commercialization of space, exemplified through the so-called ‘billionaire space race’, runs the risk of increasing space junk density and with it dangers such as Kessler Syndrome, where space debris collides with other debris, creating even more space junk in a chain reaction.
China has also nearly doubled its launches compared to the previous decade. With five active launch sites, two more under construction, and another one proposed, Chinese President Xi Jinping’s stated ambition for China “to explore the vast cosmos, develop the space industry and build China into a space power” is a realistic one. The success of China’s rapid ascent has resulted in it being the only country to actually increase its tracked space junk count, with nearly 1,000 extra pieces of debris going into orbit over the last decade.
The potential dangers of the United States’ commercially backed approach and the Chinese state-owned focus regarding space junk became evident in 2022. The crewed Chinese space station Tiangong was forced to take emergency measures to avoid a collision with two SpaceX Starlink satellites. With political tensions between the two superpowers on the rise, potential collisions between important Chinese and American pieces of space technology could cause a diplomatic incident, meaning the dangers of space junk are not simply confined to beyond the stratosphere.
One small step for man: How American space junk has changed over the decades
Awareness of space pollution increased not long after payload launches between the Cold War superpowers became a regular feature from the 1960s onward. This awareness culminated in NASA founding its Orbital Debris Program in 1979 to research solutions to the problem of space waste.
Evidently, this awareness and turn toward more sustainable space travel has had some effect. U.S. space junk that went into orbit in the 1960s and 1970s, prior to the Orbital Debris Program’s founding, is still responsible for over half (55%) of existing U.S. space waste. The remaining 45 percent comes from the five decades that followed, showing that U.S. space technology and debris mitigation efforts have become more efficient and a clear priority.
Despite the significant amount of U.S. space pollution that is represented by old and outdated material, it poses no less danger than modern space junk. Although some smaller pieces simply fall and burn up on re-entry by themselves, those that remain are a constant risk to crewed missions and active satellites alike.
Similarly, the United States has been responsible for a number of larger pieces of space waste that have fallen to Earth intact. For example, in 1979 parts of Skylab, America’s first space station, came down over Western Australia, while more recently in 2025 debris from SpaceX came down on a Polish village causing minor property damage.
With such incidents only likely to increase year on year, debris disposal cannot afford to be an afterthought. While advanced materials provided by companies like Blueshift cannot prevent space junk entirely, they support safer re-entry, reduce fragmentation, and improve resilience across a spacecraft’s lifecycle. This leads to both a safer cosmos and a safer Earth as a result.
Extreme temperatures and radiation: what other threats are there to spacecraft?
Although space junk is the most headline-grabbing threat to operating in orbit, there are numerous other dangers that must be mitigated to ensure safe space exploration. Chief among them are the extreme conditions spacecraft face in the vacuum of space.
Before reaching that vacuum, spacecraft must first resist the extreme heat of the initial launch. Post-launch, the temperature can switch from extreme heat to extreme cold in a matter of minutes. Upon atmospheric re-entry, these temperatures can once again swing wildly.
These temperature swings are also present during regular orbit. During this phase, spacecraft can experience temperature swings of over 250 °C in the space of two hours. This is due to the frequent rotation between extreme and intense sunlight and freezing temperatures in the absence of that sunlight.
This extreme temperature fluctuation, during both the mission stage and sustained orbit, can naturally cause significant amounts of thermal stress on spacecraft components. That is why it is important for spacecraft to utilize advanced thermal protection materials, such as those manufactured by Blueshift, to keep performance stable even in the most challenging cosmic environments. Blueshift’s AeroZero® technology powers its AeroZero® Thermal Protection Systems (AZ-TPS), AeroZero® Tape (AZ-Tape), and AeroZero® Flame and Thermal Barriers. All of these products are manufactured to help spacecraft withstand the hostile conditions experienced during launch, orbit, and re-entry.
AeroZero TPS and tapes provide a level of passive thermal control that far exceeds what traditional polyimide tapes can deliver in the harsh environment of space. When exposed to extreme orbital temperature swings, AeroZero reduces heat transfer far more effectively, helping spacecraft maintain thermal stability and reducing the risk of damage to sensitive components.
Testing shows that AeroZero achieves 19× lower thermal conductivity than standard polyimide tape, with values of 0.008 W/m·K versus 0.152 W/m·K. Its thermal diffusivity is also six times lower, at 0.014 m²/s versus 0.085 m²/s. This combination of low conductivity and low diffusivity makes AeroZero exceptionally well-suited for spacecraft thermal protection, where slowing heat flow is essential for long-term reliability.
Because AeroZero is engineered to minimize orbital temperature variations, it helps protect electronics, reduce thermal fatigue, and maintain a stable, predictable temperature profile across spacecraft structures. Its unique aerogel-based architecture also acts as a structured vacuum gap, further reducing heat transfer without adding significant mass.
With a composition of roughly 85% air, AeroZero offers additional advantages for spacecraft developers working to manage mass, volume, and debris-risk constraints. The material’s ultra-lightweight, ultra-thin design can be tailored to specific spacecraft geometries and easily integrated into existing assemblies, supporting the trend toward smaller, more efficient satellite systems that contribute less to long-term space debris.
Extreme temperature is not the only space-based threat to orbiting payloads. Cosmic radiation also remains a persistent danger. Left unprotected, cosmic radiation can lead to satellite malfunctions and even complete shutdowns. This makes radiation shielding a vital component of spacecraft design. Various combinations of metals, plastics, and composites can be used to help combat this invisible threat.
Shape, composition, physics, and trajectory: the factors that affect re-entry
When space junk is left to re-enter the atmosphere it does so according to a number of different factors. The first of these is the shape of the object itself. For example, space junk that has flat or wide shapes catch more air which in turn slows them down. This makes them easier to handle on their decent back to Earth which helps reduce the risk of space debris making landfall. Satellites and rocket parts that maximize drag and heat exposure are also more likely to burn up completely during re-entry which helps to ensure that people on the ground are not impacted by their descent.
The composition of an object also has strong impact on its performance during re-entry. Titanium for example is often used in spacecraft due to its density and high thermal resistance making it ideal for surviving in the harsh vacuum of space. Upon re-entry however this same toughness means that they can withstand re-entry as debris. As a result, Blueshift advocates for composite materials as a replacement for purer forms of metal. These lower density composites are more lightweight without sacrificing their ability to handle extreme temperatures. This makes them reliable for the launch and orbit phases of a mission, while making it more likely that they will burn up safely upon re-entry.
Falling space debris is also greatly affected by its angle of re-entry. If space junk falls at steep angle it is far more likely to burn up completely due to hitting the atmosphere harder and experiencing more intense heat as a result. Conversely when an object, such as a satellite, falls at a shallow angle it spreads its re-entry over a longer path. This reduces the heat but may result in more of the object surviving to Earth. When planning a controlled future re-entry it is therefore best to target a steep re-entry over an ocean to ensure that if any debris does survive it has minimal chance of hitting any populated areas.
Physics, as a factor, ties the previous three together. The laws of motion and energy dictate what happens during re-entry. For example, as the debris collides with the air molecules at extreme speeds, drag forces act to slow it down while generating extreme heat in the process. This is why the shape of the object makes such a difference, while the weight is just as important for similar reasons.
While all these factors need to be considered at all stages of a spacecrafts mission, whether it be the initial launch, its time in the cosmic vacuum, or when returning to Earth, the materials used on a space object can mitigate problems at all stages of the mission. Take Blueshift’s AeroZero tapes for satellites. These highly advanced tapes are 40x better at blocking heat transfer than traditional polyimide tapes and have already been deployed in 10,000ft2 of deployed spacecraft. In a vacuum they also performed 15x better for thermal conductivity and 8x better for thermal diffusivity, giving satellites with AeroZero tape a leading edge over those without it. Blueshift thermal protection solutions for satellites are ultra lightweight and stable, making them suitable for the vacuum of space. They also act as a thermal break by slowing unwanted conductive heating, while the option of an aluminium coating adds radiation shielding to the mix to help protect the satellite from radiative heat.
What does the future hold for space waste?
The clear trend for space junk is upward. Russia, the United States, and China show no signs of significant slowdown, while commercial spacecraft look set to continue and expand their role in the orbital arena. There are also plenty of other up-and-coming space powers that, while nowhere near the level of Russia or the United States, still contribute to the space junk problem and will likely do so even more as they develop their spacefaring capabilities in the near future. These include the EU states under the umbrella of the European Space Agency, India, and Japan.
Without investment in sustainable materials and cleanup technologies, space waste will continue to collide with itself more and more. Similarly, there will be more stories of larger pieces of space junk falling to Earth. So far, the latter has only ever resulted in light injury, but with current trends it feels like only a matter of time before significant property destruction or even a fatality occurs.
In this light, cooperation between all spacefaring parties, including both nation-states and private enterprises, is vital. Left unchecked, orbital space risks becoming the latest tragedy of the commons that humanity has so often come across where individual actors pursue short-term gain but collectively deplete a shared resource to the detriment of all. Whatever political divisions exist need to give way to proactive diplomacy, diplomatic treaties, and cooperation in the stratosphere and beyond.
As far as technological solutions are concerned, further investment must be made into cleanup operations and sustainable materials. Blueshift is a vocal advocate for sustainable spaceflight, playing an active role in researching and developing next-generation materials and infrastructure to better protect spacecraft from the dangers of the cosmos, both man-made and natural.