What Is Space Security and Why Does It Matter?

Space has been militarized since the beginning of human exploration of the heavens. The space race began in 1957 when the Soviet Union stunned the world with the launch of Sputnik, the world's first artificial satellite. The space race—a competition between the United States and the Soviet Union to see who could outpace the other in spaceflight and space technology development—stemmed from its more famous antecedent, the Cold War arms race. Subsequent tensions between the two superpowers pushed both to launch hundreds of satellites into orbit within the span of a few decades. Some of the first satellites launched into orbit were developed to support the United States' command and control systems for nuclear weapons.¹

Understandably, the distinction between space's militarization and weaponization is often misunderstood. The militarization of space includes space assets and services used, operated, or purchased by any military organization. Presently, military satellite communications systems allow US soldiers in Afghanistan to talk with friends and family back home or to communicate with commanders and other troops around the world. Mapping software, which enables services such as Uber and Google Maps, relies on military-funded and operated Global Positioning System (GPS) satellites. Also vital to our national security are early warning satellites, which detect and monitor missile and spacecraft launches worldwide.

The weaponization of space often refers to the deployment of conventional and nuclear weapons into orbit or their launch from orbit to Earth.² This definition includes ground-to-space weapons (such as a direct-ascent anti-satellite missile), spaceto-space weapons (such as maneuvering one satellite close to another in order to be within range to interfere with its electronics), and space-to-ground weapons (such as proposed space-based interceptors). These weapons categories are often referred to as counterspace weapons. Weaponizing space is consistently denounced in the international community, and the United Nations has undertaken several unsuccessful attempts to develop an international agreement to prohibit it.³

A key problem in defining and identifying counterspace weapons is that, often, the technology that could be used to destroy or degrade a space system can also be used for nondestructive, peaceful purposes as well. A great example of what space security experts refer to as "dual-use" technology is on-orbit servicing satellites—an exciting new line of commercial activity and growth in the commercial space market. These on-orbit servicing satellites are used to fix or refurbish other satellites while in orbit. This could mean refueling a satellite to extend its operational life, replacing parts of one that have been damaged during its mission, or perhaps moving one into a different orbital regime for better or newer missions. While the activities intended for onorbit servicing are benign and will lengthen the life of a satellite, the technology and capabilities of these satellites could also be used for nefarious purposes, such as pushing a satellite out of its orbit or tampering with its on-board hardware. This technology could even purposely damage a satellite by maneuvering nearby and physically striking it or employing a nonphysical weapon such as a high-powered microwave pulse to fry the electronics onboard. The key aspect differentiating a benign on-orbit servicing satellite and a counterspace weapon is intent.

Of course, intent is rarely sufficiently clear or identifiable to serve as the basis of international laws. Today, the foundational international agreement on space, the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies (commonly known as the Outer Space Treaty),⁴ only bars placing nuclear weapons and other weapons of mass destruction into orbit, on the Moon, or on other celestial bodies. In short, almost any other type of counterspace weapon is technically legal.⁵

Despite the broad legality of counterspace weapons, space is still not overtly weaponized. While there have been several infrequent anti-satellite (ASAT) tests over the years, they have always targeted satellites owned and operated by the nation preforming the test. These tests demonstrate capability while not attacking another nation's space assets. However...