Brian Weeden is the Technical Advisor for Secure World Foundationand has 16 years of professional experience in space operations and policy. His wealth of technical knowledge and expertise allow him to provide critical analysis that supports development of space policy. He is a member and former Chair of the World Economic Forum's Global Agenda Council on Space. Mr. Weeden is also a member of the Advisory Committee on Commercial Remote Sensing (ACCRES) to the National Oceanic and Atmospheric Administration (NOAA). In this third post of the Why Outer Space Matters series, he discusses the natural and human-generated threats to satellites.
Outer space has a tendency to be viewed as a peaceful, serene domain, where satellites can orbit around the Earth in relative solitude to perform what ever missions they were designed for. But in reality, outer space is a harsh domain, and full of both human-generated and natural threats that pose considerable challenges to space missions. As humanity’s use of, and reliance on, satellites and space capabilities grows, the threats could jeopardize the long-term sustainability of the space environment, and our ability to continue to use space for benefits on Earth.
Our understanding of the challenges posed by outer space has evolved over the last five decades of human activities in space. Scientific study into the space environment began in the 1950s as part of the beginning of the civil and military space programs. At the time, the main threats were impacts on satellites from small fragments of asteroids and comets, known as micrometeoroids, and high levels of radiation from energetic particles trapped in belts around the Earth and occasional solar storms from the Sun. But by the end of the 1960s, more than a dozen inadvertent explosions of satellites and rocket stages in orbit introduced a new threat: human-generated orbital space debris. In 1978, two NASA scientists - Don Kessler and Burton Cour-Palais - concluded that at some point in the future, the population of human-generated space debris would pose more of a threat than the naturally-occurring micrometeoroids. Their research, combined with the growing use of space, helped prompt governments to develop guidelines for minimizing the amount of orbital space debris created by human activities in space.
As the Cold War between the United States and Soviet Union unfolded, both sides also began to study and develop ways to attack satellites and interfere with space capabilities. At first, the concern was that one side or the other would use orbiting nuclear weapons to launch an attack that avoided early warning systems. After that tactic was prohibited by the 1967 Outer Space Treaty, the focus shifted to developing, and testing, anti-satellite (ASAT) weapons that could degrade or even destroy satellites that provided military effects on Earth, such as intelligence and reconnaissance satellites that could be used for targeting. However, the close linkage between satellites and nuclear warning meant that most ASAT concepts were never put into practice for fear of triggering a nuclear war. Most of the interest in developing and using ASAT weapons collapsed along with the Soviet Union in the early 1990s, at least for a short while.
By the end of the 1990s, the progress on implementing space debris mitigation guidelines had begun to stem the growth of space debris, but the positive gains were soon undone by other events. In 2007, China tested a ground-launched ASAT weapon by destroying one of its own defunct weather satellites, generating more than 3,000 pieces of space debris in the process. In 2008, the United States used a ship-launched missile defense interceptor to destroy one of its own defunct intelligence satellites, ostensibly to prevent its payload of frozen fuel from endangering people on Earth. In 2009, an American Iridium commercial communications satellite collided with a defunct Russian military communications satellite, creating nearly 2,000 more pieces of space debris. These two events occurred at a high enough altitude - around 800 kilometers - that the resulting space debris will persist in orbit for decades, posing a long-term threat to all the satellites in low Earth orbit. Moreover, the US and Chinese tests demonstrated a renewed interest in ASAT capabilities, and the potentially willingness to put them to use.
Today, the space environment poses even more risks for the future of space activities. The more than 1,400 functional satellites currently orbiting the Earth have to contend daily with the nearly 500,000 pieces of human-generated space debris also orbiting the Earth. In 2014, satellite operators performed more than 120 maneuvers to change their satellites’ orbital trajectory in order to reduce the probability of a collision with one of the 20,000 pieces of large space debris bigger than a baseball. But with the current level of space situational awareness, it’s not possible to track and dodge all of the smaller space debris, which can damage a satellite on impact, as the European Union found out when its Sentinel-1A satellite was struck by a millimeter-sized piece of space debris in August 2016. And the congestion issues are likely to get even more challenging, with commercial companies planning to deploy thousands of small satellites in large constellations over the next decade.
At the same time, there is a growing concern that conflict on Earth might extend into space. China has continued testing ASAT weapons in space, albeit without generating additional orbital space debris. There is evidence Russia has revived at least a few of its Cold War-era ASAT programs, and is also using satellite jammers in current military operations. The motivation for both appears to be the increased American use of, and thus reliance on, space capabilities for military activities and power projection around the world. As a result, senior US military leaders have begun openly talking about the risks of a war in space, a war they profess they do not want but nonetheless must be “prepared to win.” Meanwhile, many other countries around the world are developing their own military space capabilities, primarily for intelligence and reconnaissance, and the technologies for jamming or interfering with satellites are steadily proliferating, even to non-state actors.
The growing environmental threats to satellites, increased congestion on orbit, and the possibility of conflict extending into space, pose challenges humanity will need to tackle over the next several years. Some efforts are already underway, such as the discussions within the United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS) to develop guidelines for the long-term sustainability of space activities, and discussions within the United States to improve space situational awareness (SSA), and develop a civil space traffic management (STM) regime. While important, these efforts are likely not going to be sufficient. The global space community will need to decide what additional measures are necessary to help ensure that space can continue to provide benefits on Earth long into the future.
Schedule of blog posts:
- Why Outer Space Matters: Series Introduction - Mr. Rob Ramey (ICRC)
- Humanitarian Uses of Space - Ms. Krystal Wilson (Secure World Foundation)
- Satellites Face Increasing Natural and Human-Generated Threats - Brian Weeden (Secure World Foundation)
- International Space Law: A Brief Introduction - Major Susan Trepczynski (United States Air Force)
- International Humanitarian Law: A Brief Introduction - Dr. Dale Stephens (University of Adelaide School of Law)
This blog series comes out of the October 2016 Inaugural Plenary of the MILAMOS Project in Montreal, Canada sponsored by the McGill Centre for Research in Air and Space Law (CRASL), the University of Adelaide's Research Unit on Military Law and Ethics (RUMLAE). The ICRC participated in the plenary as an Institutional Contributer.