On July 12, 2019, the Department of National Defence (DND) presented a call to help develop a viable and cost-effective way to track and de-orbit space debris[1]. With the rapid growth in the space industry projected over the next decade, the call comes at a critical point where accumulated space debris has raised the risk of collision for existing and planned satellites. This is becoming especially important given the rise of so-called mega-constellations, where the number of operational satellites is predicted to rise from less than 2,000 to more than 20,000 in the next decade.
The question that normally accompanies these discussions is this: why, in the context of competing government priorities and resources, would Canada allocate valuable resources to removing space debris?
The Space Debris Problem
Orbital debris represents a growing threat to the operation of satellites. According to ESA’s Space Debris Office, there are currently hundreds of thousands of debris objects greater than one centimeter in diameter in Earth’s orbit, and approximately 128 million objects between one centimetre and one millimeter[2]. The U.S. Space Surveillance Network (SSN) operates a catalogue that routinely tracks more than 21,000 orbiting items larger than 10 centimeters in the orbits from Low Earth Orbit (LEO) to Geostationary Orbit (GEO). These objects, the vast majority of which are classified as debris, are mostly the remnants of space objects such as defunct satellites, discarded rocket stages, and debris created by collisions between space objects.
Before 2007, the primary source of space debris was the explosion of old launch-vehicle upper stages. Upper stages are used to give satellites the final kick into the desired orbit and were most often left to slowly drift back down to Earth. However, these rocket bodies had a small remnant of fuel. Often, these rocket bodies would explode due to the heating of the enclosed propellant and material fatigue.[3]
However, because of the growth of commercial and private space activity, it is anticipated that debris will increase over the next few years, despite the international debris mitigation guidelines. According to one review on the state of space debris published in Science, “[i]n reality, the situation will undoubtedly be worse because spacecraft and their orbital stages will continue to be launched.”[4]
The key element of the space debris problem is the increase in the space object population in LEO. As the number of objects grows, the greater the chance for collisions increases, risking a cascade of collisions. This effect is referred to as the “Kessler Syndrome” and was famously portrayed in popular culture by the movie Gravity. In addition, the higher the altitude, the longer the space debris will remain in orbit. Orbital debris below 600 kilometers returns to Earth and burns up within several years. However, at altitudes of 800 kilometers or higher, the orbital decay lasts decades, with debris not expected to fall back to Earth before a century or more.
Space operators can expect a sharp increase in the number of conjunction warnings as the number of catalogued objects increases. According to a presentation made at the Military Space Surveillance conference in London, England this past February, the Combined Space Operations Center, operated by the USAF, issued 6.7 million satellite conjunction alerts last year. In addition, the Combined Space Operations Center only provides conjunction warnings on objects larger than 10 centimeters. Impact with an object 1 centimeter or larger will cause damage likely to destroy a satellite[5], and yet objects of this size cannot be reliably tracked. Therefore, there is a large latent risk from unobserved debris with the highest risk to operational satellites coming from lethal and non-trackable debris.
(In)Famous Debris Creation Events
There are three prominent debris creation events that have added to the space debris problem. These are the intentional anti-satellite tests against the Chinese Fen Yun 1C satellite, the Mission Shakti conducted by India and the accidental collision of Kosmos-2251 and Iridium 33.
The Fengyun 1C was destroyed in early 2007 by the Chinese military using a “kinetic kill vehicle,” which rammed the satellite at over 16 km/s.[6] The resultant explosion created approximately 3,000 pieces of debris that continue to pose a danger to spacecraft in LEO.[7]
More recently, on 27 March 2019, India successfully executed an anti-satellite test at an altitude which it claimed to be low enough that any debris created would be burned-up on re-entry into the Earth’s atmosphere. The test created more than 400 pieces of debris, with at least two dozen fragments being ejected upwards past the International Space Station (ISS). Indian officials have provided an abundance of information on the test, and claimed the test was a “historic feat” and the nation is now in an elite club of “super space powers” along with the U.S., Russia and China.[8]
The Kosmos-2251 and Iridium 33 collision was another collision event, albeit accidental. Launched in 1993, Kosmos-2251 was a 950-kilogram military communication satellite operating in LEO since 1995, while Iridium 33 was a commercial communications satellite. The collision occurred at a speed of 42,120 km/h in LEO above Siberia. The US SSN catalogued over 2,000 large debris fragments resulting from the collision.[9]
Two of these events, the Chinese and Indian tests, were particularly detrimental to the safety of spacecraft. Both events were irresponsible as the anti-satellite tests were not formally communicated prior to launch and conducted with no declared active debris removal plan in place. Following the United Nations (UN) Space Debris Mitigation Guidelines, both events have also increased the risk of collision through the intentional destruction of an on-orbit spacecraft and created long-lived debris.[10] In addressing the space debris problem, international norms of responsible behaviour in space must be addressed.
Canada, DND and the Timeliness of a Debris Removal Mission
Prior to the proposal call, the DND, like most space operators, had relied on the “Big Sky” theory to deal with space debris. Space was a big place, and the likelihood of two objects colliding was exceptionally small. As space becomes more congested, contested and competitive, reliance on the Big Sky theory has become untenable.
DND has maintained a long partnership with the United States Air Force in supporting space surveillance activities, dating back to the 1950s when they operated the Baker Nunn Satellite Tracking cameras in Cold Lake and St-Margarets from the mid-1950s to mid-1970s. DND continued to support space surveillance activities over the years, most notably through deployments to U.S. space surveillance sites. In 2013, DND again began providing data to the U.S. space surveillance network via the Canadian Space Surveillance System (CSSS). The centerpiece of the CSSS is the Sapphire satellite. Launched in 2013, Sapphire supports space object tracking of Medium Earth Orbit (MEO) and GEO space objects.
While Sapphire fills an important gap in Canadian and allied space capabilities, by itself it does not provide enough data to support space debris tracking and situational awareness. By providing a unique niche capability to the SSN, Canada has maintained privileged access to the most sophisticated space object catalogue in the world. With the planned Surveillance of Space 2 project, Canada will continue to provide a capability to the SSN, thereby continuing to support future space surveillance requirements, including a debris mitigation or removal mission.
Supporting DND’s commitments to the SSN, the Strong, Secure, Engaged (SSE) policy outlines several initiatives that would support a space debris removal mission. The SSE states that a space debris mitigation mission would significantly support DND and CAF’s commitment to defend and protect military space capabilities while assuring freedom of access to space.[11] Moreover, integrating a prototype space debris removal capability into Canada’s space capabilities responds to the requirement to produce cutting-edge research and development on new space technologies. Such a mission would be technically challenging and precedent setting.
A debris removal capability not only supports the SSE and Canada’s national security commitments to the Combined Space Operations Initiative (CSpO), but also the United Nations’ Space Debris Mitigation Guidelines. A debris removal mission would allow Canada to promote its national interests, including the peaceful uses of space and demonstrably promoting norms of responsible behaviour in space by example in debris mitigation.[12]
Anticipated Space Debris Removal Methods
Canada does not operate a space debris removal capability. Indeed, it has been noted in the recent call for ideas that “[t]here are no operational debris removal capabilities in use, globally, and existing prototypes lack important capabilities and have proven ineffective.”[13]
Although DND has yet to determine what concept would be adopted, space debris removal technologies come in all shapes and sizes. There exist various Active Debris Removal (ADR) techniques currently in development. These prototypes include a laser that would knock debris out of orbit, satellites that would rendezvous with debris and either catch it with a net, harpoon it or even magnetically attached themselves to the debris.[14] While the development of some ADR technologies are more advanced, most systems remain in the conceptual and experimentation phase.
A Future Canadian Space Debris Removal Mission
Today, space is very different from what it was back at the dawn of spaceflight. Space capabilities have become an essential element of not only national security activities, but for human safety, security and commerce. Adapting to these new and emerging challenges and while ensuring continued access to space is critical. A debris mitigation and removal mission is timely and fits as a critical component of the national security strategy of any space-faring nation.
A space debris removal capability could exploit a niche capability gap similar to what Sapphire accomplished during its conception. Not only could the CAF deploy a system that could ensure its space assets could operate free from the threat of a collision of debris, but it could reinforce Canada’s commitment to the responsible uses of space entrenched in the UN’s Mitigation Guidelines.
Lastly, as examined briefly in this article, various ADR techniques are becoming viable. As these techniques are refined, the feasibility of initiating debris collection and removal operations will become more likely. For Canada, it therefore makes sense to address the space debris problem now and with increased vigor.
A future space debris removal mission is both viable and essential to the space security of Canada and its allies. Canadians are developing the technology needed to clean large sections of the orbits. Along with the SSE, a one-of-a-kind opportunity has presented itself where Canada could take a strong leadership role in blazing the way in space debris mitigation and removal. This opportunity would enable a typically Canadian outlook supporting rules of responsible behaviour in space, thereby setting the bar for future space activities in the decades to come.
Kiernan McClelland is a Policy Analyst at Space Strategies
Consulting Ltd., and a PhD Candidate at Carleton University.
[1] https://buyandsell.gc.ca/procurement-data/tender-notice/PW-19-00880696; https://www.cbc.ca/news/canada/ottawa/dnd-rfp-cleaning-up-space-junk-1.5236544
[2] https://m.esa.int/Our_Activities/Space_Safety/Space_Debris/Space_debris_by_the_numbers
[3] http://www.spacesafetymagazine.com/space-debris/mitigation/
[4] https://science.sciencemag.org/content/311/5759/340/tab-article-info
[5] Theodore J. Muelhaupt, Marlon E. Sorge, Jamie Morin, Robert S. Wilson, “Space traffic management in the new space era,” The Journal of Space Safety Engineering, 6 (2019): 80-87.
[6] https://www.globalsecurity.org/space/world/china/asat.htm
[7] http://www.spacesafetymagazine.com/space-debris/mitigation/
[8] TIME, India’s Narendra Modi Projects Military Might By Testing Anti-Satellite Missile | TIME, 2019, https://www.youtube.com/watch?v=zwbXOoIwWkM; Kelsey Davenport, “Indian ASAT Test Raises Space Risks | Arms Control Association,” Arms Control Association, May 2019, https://www.armscontrol.org/act/2019-05/news/indian-asat-test-raises-space-risks.
[9]https://web.archive.org/web/20100527132915/http://orbitaldebris.jsc.nasa.gov/newsletter/pdfs/ODQNv13i2.pdf
[10] http://www.unoosa.org/pdf/publications/st_space_49E.pdf
[11] http://dgpaapp.forces.gc.ca/en/canada-defence-policy/docs/canada-defence-policy-report.pdf
[12] http://www.unoosa.org/pdf/publications/st_space_49E.pdf
[13] https://buyandsell.gc.ca/procurement-data/tender-notice/PW-19-00880696
[14] C. Priyant Mark, Surekha Kamath, Review of Active Space Debris Removal Methods, Space Policy.