Saving Space from ‘Star Wars’-Style Misperceptions


Dogfights in orbit. Spacecraft blasting at each other with lasers. Targets that erupt into fireballs and vanish.

The world still doesn’t know what a conflict in space might look like, because the norms and capabilities of such an event are still largely unwritten. But to many, the idea of a war in space conjures imagery from Star Wars, which George Lucas famously modeled after World War II air combat. One thing is certain: If policymakers imagine space to be the same kind of warfighting domain as its terrestrial counterparts, the sustainability of space as a commons is at risk. In a world where space wars imitate Star Wars, orbital debris poses an existential threat to the future of space development. Now is the time for the United States to seriously consider arms control measures for anti-satellite weapons that generate orbital debris.



The Pentagon recently released a new Defense Space Strategy, which prioritizes the development of a “comprehensive military advantage in space.” It plans to accomplish this, among other things, by: “develop[ing] and document[ing] doctrinal foundations of military spacepower.” On one hand, it is refreshing to see a high-level document explicitly acknowledge the infancy of U.S. space doctrine. There’s a great deal of opportunity to challenge existing norms and innovate upon longstanding assumptions, and many of the arguments for and against the development of military space capabilities rehash the not-so-distant debates over airpower. But with this opportunity comes danger.

The Trump administration’s primary justification for a Space Force was that space is now a warfighting domain, and that a separate entity was required to meet the unique challenges posed by this environment. To be clear, there are many practical benefits to a separate service, perhaps most importantly the professionalization and elevation of a dedicated space cadre with unique warfighting skills. But the entire branding and existence of a Space Force reinforces the idea that wars will be fought in space.

Space provides unique and irreplaceable benefits to humanity. The “ultimate high ground” offers vantage points from which to collect and distribute information about the happenings on Earth, and to do so with global coverage at incredible speed. The military value of space is unquestioned: With access to space, nations can communicate securely, spy on their adversaries, and enable navigation and timing services.

Space, however, is not suited for every type of mission. It is wildly impractical to develop weapon systems that attack targets on Earth from space. Traditional terrestrial forces can attack terrestrial targets far more effectively and cheaply. As a result, most if not all military space assets can be characterized as components of an information dominance infrastructure as opposed to force-projection platforms (the exception being satellites that attack other satellites).

So now that the United States is officially constructing doctrines and capabilities from a fresh canvas, it serves as a timely opportunity to argue why debris-generating anti-satellite weapons are so ill-advised. These systems, known as kinetic weapons because they shoot targets at high velocities, will have long-lasting consequences for our way of life. To illustrate what’s at stake, let’s discuss the nature of the risk and how the United States may achieve space dominance without undermining its role as a responsible steward for space development.

It’s About Space Junk

The most important consideration for both military and civilian space users is that the space environment is itself a resource — one that can be degraded and rendered unusable for all parties for generations. Orbital debris is a serious problem for all spacefaring and aspirant nations. A 1-pound piece of shrapnel from an old rocket body traveling at orbital velocities has roughly the same kinetic energy as a dump truck traveling 70 miles per hour. So when you imagine the collision of small debris in space, you can reasonably estimate it’s similar to getting hit by a dump truck on the highway. And space debris has a long life: Some objects will be circling the Earth for hundreds or thousands of years.

The precise risk posed by orbital debris is still unclear. In the 1970s, a NASA scientist named Donald Kessler predicted that once the space environment is sufficiently populated with satellites, any collision will cause a chain reaction and render the orbit unusable. Today, we know that space has more debris than we can measure, but we cannot be sure exactly how dangerous it is because we do not have all of the data.

Current technology enables us to track debris that’s at least 4 inches (10 centimeters) in diameter, which is the scale at which the U.S. Space Surveillance Network catalogues objects. Right now, the network has catalogued roughly 20,000 objects in orbit. One key feature of these objects is that we are able to predict their future trajectory with reasonable skill. It is possible to observe smaller debris, with some radars seeing objects as small as a few millimeters. These systems, however, are able to provide only a statistical assessment of the amount of smaller debris. But small debris is still incredibly lethal. Experts believe that debris as small as 5 millimeters can cause mission-ending damage.

Two events generated nearly half of the tracked debris objects in low-Earth orbit, the region of space that extends from the outer reaches of Earth’s atmosphere to roughly 1,200 miles in altitude and that is home to most artificial satellites. In 2009, a Russian communications satellite and a U.S. commercial communications satellite collided by accident, causing a plume of nearly 2,000 tracked daughter objects. Analysts suggest that at least half of these objects will be in orbit for the next century. In 2007, China tested a direct-ascent anti-satellite weapon against one of its nonoperational weather satellites, Fengyun-1C. This one test created more than 3,000 tracked objects, and roughly 80 percent of the resulting debris is expected to orbit for the next century. Evidence suggests that for a factor of 10 reduction in debris size, the population of debris increases by 100. So while there are about 2,000 catalogued objects from the 2009 Iridium-Cosmos collision that are roughly 10 centimeters and larger, we can assume there are approximately 200,000 objects larger than 1 centimeter.

Life and Death of a Satellite

All satellites are designed with death in mind. NASA has standards for how satellite missions should plan for end-of-life, whether by plunging back into Earth’s atmosphere or relocating to a “graveyard” orbit. The utility and investment in a satellite is often figured in terms of lifetime of service. Consumables like fuel, degrading components like batteries and motors, and environmental risk such as space weather and orbital debris determine a satellite’s operational life.

The value of a space asset is almost always derived from its continued operation. Not only do these assets operate in an isolated and dangerous environment, the degradation of its value is almost always irreversible. This is in contrast to nearly every other kind of capital asset: Cars, bridges, and brands can be repaired. With a few notable exceptions, satellites cannot.

This reality drives the design and production of modern space assets, so most spacecraft go through extensive testing before launch to ensure they will survive their design life. Newer concepts such as constellations of small satellites reduce risk by distributing utility over many assets, but these systems often require regular launches to replenish the architecture’s peak functionality.

Debris accumulation does not necessarily prevent a satellite from being successfully launched or entering service. However, the satellite will have a shorter life expectancy and be prone to sudden failure, reducing its overall utility. And if the satellite is disabled before it can safely fall back to earth, it will continue to pose a hazard for other spacecraft. The sensitivity of operational lifetime to quantity of debris is still unknown, but it is well-established that as long as we are unable to clean up vast regions of space, the problem will only get worse in our lifetime.

Right now, orbital debris is not the biggest limitation to a satellite’s life, but it could be. If the risk posed by orbital debris — no matter the cause — begins to drive down the lifetime of satellite missions, the design paradigm will follow. In some senses, this shift is inevitable. In 2005, NASA conducted a study and found that even if no new launches were conducted, the population of tracked debris would increase faster than atmospheric drag would remove objects based on future collisions alone. The timescale for these impacts to be realized is unclear.

Weaponizing Space

At a National Space Council meeting last year, Vice President Mike Pence asserted that the United States was already in a space race, implying that Russia and China have actively weaponized space and the United States must respond in kind. The U.S. intelligence community assesses that Russian and Chinese development of direct-ascent anti-satellite weapons is largely to counter the perceived advantage the United States enjoys in space. These systems have been tested in some form by China, India, and the United States, and most recently by Russia just a few months ago. Amid this discussion of competition, however, it is still unclear how such a weapon system could be used effectively, and whether there is wisdom in any nation fielding these capabilities.

Almost all scenarios in which a kinetic anti-satellite weapon can be deployed are inherently self-harming, no matter the operator. Kinetic weapons, whether space- or ground-based, create huge plumes of orbital debris and serve limited strategic value.

A relatively small number of kinetic strikes can significantly increase the risk to a large number of satellites in an orbital regime. On the surface, some actors may consider this a feature, not a bug, as debris serves as a de facto force multiplier. However, this risk takes time to propagate: Depending on the nature of the attack, it may take weeks to years for the debris field to collide with other assets in orbit. Therefore, it is unlikely an entire constellation can be wiped out with one attack instantaneously. Instead, the debris environment will grow increasingly congested as a small fraction of the initial debris collides with other objects. Notwithstanding, the magnitude of harm a single attack causes should serve to emphasize the caution required: There will be a well-understood threshold for use, because single events will have outsized, watershed impacts.

For the United States, the self-harming features of these weapons is clear. As the current leader in space infrastructure, the United States is preferentially vulnerable to both debris and anti-satellite weapons. Any weapon, American or otherwise, that creates new debris harms U.S. interests. Developing and maturing this class of weapons invites potentially destabilizing arms race conditions, where aspirant space powers have incentives to develop or proliferate a capability with global and long-lived consequences. Fielding and using these weapons risks the tremendous wartime and peacetime advantages space technologies provide and normalizes destructive behavior.

Competitors might think neutralizing the United States’ perceived advantages in space is in their national interest. This is a mistake, and these weapons harm these countries’ strategic interests and calculations. The logic is threefold. First is the permanence of the consequences. Imagine if a certain class of cyber weapon took down the internet, forever, or if a bomb rendered a strategic shipping channel unusable, forever. Even if you do not enjoy the benefits of this infrastructure now, these are almost certainly things you want in the future.

The second deterrent is the immediate net effect. If the United States successfully implements resilient space systems that can survive individual failures, and demonstrates a robust capability to replenish assets as they expire, then the debris can actually pose a particular harm to immature space operators. Because the risk of space debris may accumulate at longer timescales than conflict, the debris plume may not impact other satellites until well after the conflict ends. In the meantime, U.S. assets may be redesigned and redeployed to less congested orbits for longer-term sustainability. Adversaries will suffer a much steeper learning curve.

The third deterrent is the response dynamic. U.S. defense officials have long articulated that any U.S. response to an attack on its satellites will not be limited to space, but also likely will involve other domains. The irreversible contamination of a commons will also motivate and unify the international community against would-be attackers. Blowing up a satellite would not just violate norms; it could rob the globe of accurate weather forecasts, satellite communication, or any other space-enabled function. These reactions increase the cost to adversaries who may be interested in testing the escalation dynamics of space attacks.

Unfortunately, these deterrents require adjudicating long-term interests over potential short-term tactical advantages, and too often, nations take myopic actions. This places the sustainability of the space environment in jeopardy.

What Is to Be Done?

It is worth mentioning that there are several types of weapons and tactics that can be used to neutralize space systems that do not require physical destruction of the space asset in orbit. This can include lasers, jammers, cyber weapons, or a whole host of attacks on ground targets, like bombing a ground station. While these methods each pose unique features and trade-offs to warfighters and defense planners, they do not irreversibly contaminate a common resource.

Since debris-generating weapons pose a unique danger to all, and because the counter-space mission can be effectively attained by other weapons classes, this juncture may be an opportunity for the United States to revisit space arms control.

Russia and China continue to circulate the draft Treaty on the Prevention of the Placement of Weapons in Outer Space, but it conveniently excludes dangerous debris-generating weapons launched from the ground developed by both countries. Russia’s recent reckless and aggressive maneuvers and weapons testing undermine its messaging on this matter. China’s anti-satellite test still remains the largest single-event source of debris in orbit.

To date, the Trump administration seems to be unwilling to take any step other than normative development. As Aaron Bateman persuasively argued, developing robust norms in space is essential. Earlier anemic responses to the Indian anti-satellite test undermined global space security and conceded an opportunity to promote space norms. There is progress underway: The Trump administration’s new Artemis Accords offer a renewed opportunity to cultivate norms by tying behavior to access to U.S. space infrastructure.

But merely developing norms is not enough. If we know that a certain class of weapons not only fundamentally threatens the sustainable development of space and its enduring benefits to humanity, but also provides dubious strategic value, what does it say about us if we do not work to remove such weapons from use?



Charles Powell is a doctoral student at the University of Michigan, where he studies novel ways to look at Earth from space. Previously, he advised the National Oceanic and Atmospheric Administration administrator on the nation’s environmental observation infrastructure and provided space policy expertise to the Department of Commerce. Powell was a 2016 Herbert Scoville Jr. Peace Fellow and has supported four satellite launch campaigns.

This work is the author’s own and does not represent the views of the U.S. government or the U.S. Department of Commerce.

Image: U.S. Air Force photo by Joshua Conti

CORRECTION: Due to an arithmetic error, a previous version of this article overstated the proportion of tracked debris objects generated by the 2007 Chinese ASAT and 2009 Iridium-Cosmos fragmentation events. The figure has been corrected from “over 60 percent” to “nearly half.”