Small Satellites, Heavy Burdens: Rethinking Proposed De-Orbiting and Propulsion Requirements for CubeSats in Canada

(uniquement en anglais)

par Jessica Von Hollen

Employees, researchers, and students across Canada are actively designing, constructing, and continuing to launch miniature satellites known as “CubeSats”. CubeSats offer invaluable opportunities for the next generation of Canada’s workforce to gain experience in developing flight hardware and conducting space missions.¹ They provide for low-cost development of flight-qualified technology, foster innovative public-private partnerships, and create opportunities to build expertise and skills for careers in the space sector.² However, current and evolving de-orbiting and space debris mitigation guidelines place disproportionate burdens on CubeSat developers, given the challenges of implementing de-orbiting and propulsion technologies due to CubeSats’ small size and the common resource constraints faced by development teams.³ Awareness and proactive response to these requirements is especially timely, given recently proposed updates to Canada’s licensing framework and conditions of licence for space debris and collision mitigation, which include a stricter deorbiting timeline and active propulsion technology for satellites operating at over 400 km of altitude.⁴ While essential for the long-term sustainability of space activities, proposed space debris and collision mitigation requirements pose significant design challenges for CubeSat developers, underscoring the need for a flexible regulatory framework and increased investment in research and development to support Canada’s continued advancement in this critical sector.

The Significance of a Small Satellite

CubeSats have been instrumental in helping private developers enter the aerospace technology sector and in fostering Canada’s international participation and presence in the space industry. A prime example is Kepler Communications, founded in 2015 by University of Toronto graduates, which initially developed CubeSats to provide real-time data relay services for Internet of Things (IoT) devices.⁵ Their early satellites (KIPP, CASE, and TARS) were built based on the CubeSat standard. By 2023, the company had secured over US$200 million in funding and forged partnerships with international companies like Tesat-Spacecom and Axiom Space to develop an inter-satellite network, positioning Canada as a significant contributor to global space communications.⁶ Additionally, CubeSat student projects play a crucial role in developing the skills and passion needed by future professionals to contribute to aerospace advancements. Arad Gharagozli, founder of GALAXIA Mission Systems Inc., emphasized the importance of his experience as part of Dalhousie University’s CubeSat team. GALAXIA is now working to develop the first software-defined Earth observation platform and aims to provide a shared-access platform hosting a variety of powerful space sensors. This initiative is designed to bring sophisticated modern computation to space and make it accessible to small-to-medium-sized businesses that have historically faced significant barriers to entry.⁷ These innovative companies highlight the crucial role of CubeSat development in sustaining educational advancement and fostering competitiveness within the private sector of the aerospace industry.

The importance of CubeSats is also evident in their suitability for addressing Canadian social and environmental challenges. For instance, CubeSat imagery has been used to reveal the previously underestimated impact of fine-scale shoreline fluctuations in Arctic-Boreal lakes on surface water and greenhouse gas emissions. These findings have reshaped conventional understandings of carbon cycling and climate feedback in the Arctic; insights made possible only through the high-resolution, high-frequency data that CubeSats are well equipped to provide.⁸ A team from the community of Chesterfield Inlet, in collaboration with the Universities of Manitoba and Calgary, is currently developing ArcticSat, a CubeSat designed to deliver timely, cost-effective, and accurate data on open water, snow, and sea ice conditions to northern Inuit and Indigenous communities to respond effectively to climate and seasonal changes. The team aims enhance community safety by informing activities such as freshwater collection, hunting (critical to Inuit food culture and addressing food insecurity) and travel between communities.⁹ These use cases demonstrate the value of CubeSats in providing precise and accessible data to address pressing social and environmental challenges within Canada. Despite their utility, evolving regulations surrounding space debris, deorbiting, and propulsion could present obstacles to CubeSat development in Canada.

Current and Proposed Regulations

Proposed Requirement A1: Space Debris Mitigation Requirements: Innovation, Science and Economic Development Canada (ISED), a Department of the Government of Canada, administers Canada’s licensing regime for satellites.¹⁰ ISED currently requires licensees of non-geostationary satellites (NGSOs), including most CubeSats, to submit a space debris mitigation plan that is consistent with the guidelines issued by the Inter-Agency Debris Committee (IADC), including the requirement for the satellite(s) to de-orbit within 25 years of end of operational life.¹¹ However, ISED’s current measures do not define metrics or detailed measures that should be included in the space debris plan, except for the de-orbit timeline. ISED is currently proposing that NGSO licensees in low earth orbit (LEO) be required to de-orbit their satellite as soon as practicable, but no later than five years following the end of operational life of the satellite. ISED further proposes that the five-year de-orbit requirement be supported by a reliability metric for successful post-mission disposal of a minimum of 90% for an individual spacecraft and 99% for each spacecraft that is part of a constellation (two or more satellites in the same mission).¹²

Developing propulsion systems that meet stringent reliability metrics (90% for individual satellites, 99% for constellations) may require expertise that is not easily accessible for small teams or startups without significant funding or experience in high-performance systems.¹³ This challenge may is compounded by uncertainty about how the relevant reliability metrics will be defined, tested, and enforced, potentially leading to high costs and harmful, avoidable design trade-offs for small teams. For example, while propulsion systems are a viable and potentially effective means of meeting the proposed deorbiting requirements (with the associated challenges for CubeSats discussed under Proposed Requirement A3 below), alternative new technologies such as electrodynamic tethers and drag sails may offer comparable theoretical effectiveness and be easier to implement.¹⁴ However, their experimental nature may make them more difficult to qualify for regulatory approval. Furthermore, many CubeSats (particularly those launched at or around 400 km altitude) will deorbit naturally due to their small size and the impact of atmospheric forces.¹⁵ It is unclear what lengths such relatively innocuous missions may still be required to go to in demonstrating compliance. Some CubeSat missions above that altitude may be capable of naturally deorbiting slightly outside the proposed five-year window, though the burden of compliance may not be justified in such cases where the benefits of earlier deorbiting only marginally exceed the five-year guideline. In summary, the proposed five-year deorbiting timeline, supported by a proven 90% or 99% reliability requirement, could place undue burdens on CubeSat developers, due to uncertainties surrounding measurement standards, less pressing concerns about space debris and deorbiting timelines for certain CubeSat missions, and the inherent resource limitations faced by many CubeSat developers.

Proposed Requirement A3: Proposed Propulsion Requirement: ISED also proposes to mandate maneuverability through active propulsion, with redundancy, for all spacecraft operating at and above 400 km, which is the average altitude at which the International Space Station (ISS) operates, for the security of the ISS and those who live and work there. The ISED discusses maneuverability as “a deliberate change in the trajectory of a satellite in order to avoid a collision”.¹⁶ While the ISED does not define active propulsion in its proposal, active propulsion systems on CubeSats can be understood as having internal mechanisms (e.g., motors, engines) that produce the necessary force to move, and typically require energy (e.g., fuel, electricity).¹⁷ Passive propulsion relies on natural forces or simple devices, like drag sails or magnetic damping, offering limited control without adding energy to the system through fuel.¹⁸

The active propulsion requirement for CubeSats above 400 km may negatively affect many design teams. Most CubeSats operate at an altitude between 350-700 km above earth’s surface, meaning that this requirement is likely to affect the average CubeSat design team.¹⁹ Few CubeSats are functionally maneuverable, especially when considering the functional requirements for effective collision avoidance (e.g., the ability for a satellite to actually change their orbit or move out of the way in a short period of time).²⁰ CubeSats are small, often limited to 1U (10x10x10 cm), with minimal space for additional hardware.²¹ Integrating a propulsion system requires efficient use of this limited space, and typical propulsion technologies may be too large or heavy for such small platforms.²² CubeSat often face challenges regarding energy and power constraints, volume and mass limitations, and propellant storage issues, particularly considering a relatively high fuel consumption. Propulsion systems, especially those with redundancy, can increase weight significantly. This impacts the power budget and thermal management of CubeSats, which are already constrained. Active propulsion, especially with reliability requirements, typically means advanced technologies like electric or chemical propulsion, which are expensive and complex to integrate.²³ For these reasons, most CubeSats lack active propulsion systems altogether, not even considering limitations in training and resources for small or emerging design teams.²⁴ The added redundancy for reliability further complicates the design. In summary, the requirement for active propulsion on missions above 400 km in altitude is likely to have a negative impact on many CubeSat missions, given their typical operating altitudes and inherent limitations, such as weight and system complexity.

Recommendations

Tiered Regulatory Approach:Less stringent global regulations regarding active propulsion and deorbiting may suggest the utility of a flexible or tiered approach to requirements for small spacecraft such as CubeSats. For example, America’s Federal Communications Commission (FCC) implemented an alternative application process which does not require small satellites (defined in part by the CubeSat standard – 10 cm x 10 cm x 10 cm in size) being deployed below 600 km altitude to have the capability to perform collision avoidance and de-orbit maneuvers using propulsion.²⁵ The FCC mandates that satellites above 400 km need to incorporate maneuverability capabilities, though these may involve propulsion systems or other techniques like drag sails to recognize concerns regarding safety and collision with the International Space Station while enabling flexibility, particularly for small satellites.²⁶ Furthermore, while the FCC mandates a five-year deorbit rule for LEO satellites, it does not mandate a minimum success rate for each deorbit attempt (unlike the proposed Canadian update).²⁷ Finally, FCC also allows for applications for waiver of the five-year deorbit requirement in the event of a failure or anomaly giving rise to non-compliance.²⁸ Canada could introduce similar flexibilities or exceptions for CubeSats. These could include allowing concessions based on a satellite’s size and proposed altitude (or a “tiered” system), such as broader maneuverability options, waiving additional deorbiting licensing requirements for CubeSats likely to passively deorbit within or near the five-year timeline, and recognizing passive or experimental deorbiting technologies when assessing a satellite’s deorbiting reliability.

Clarity:As mentioned in relation to requirement A1, the 90% or 99% reliability metric for deorbiting could lead to uncertainty about how reliability will be measured and enforced. To support low-resourced development teams in achieving licensing and compliance, regulatory authorities could offer clear, publicly accessible designs or models that demonstrate compliance, either by default based on the satellite’s size and proposed altitude or by incorporating approved deorbiting measures, including lower-cost and experimental options.²⁹

Educational and Research Support:Other jurisdictions proposing criteria for space debris and collision mitigation signal investment in research and development to support satellite developers and ease their burdens regarding debris and collision avoidance. For example, the European Space Agency (ESA) is participating in an extensive Zero Debris initiative, which recently included the successful deployment of a sail aboard a CubeSat with the goal of sail catching more of Earth’s upper atmosphere, allowing the CubeSat to deorbit in a matter of months instead of years.³⁰ In proposing increasingly stringent debris and collision avoidance regulations, the Canadian government could similarly increase investment in the development and deployment of cost-effective deorbiting and maneuverability technologies tailored to CubeSats, with the aim of making compliant solutions more accessible to educational institutions and small businesses.

Conclusion

While space debris mitigation and deorbiting requirements are essential for the long-term sustainability of space exploration, they present considerable design challenges for CubeSat developers, particularly in integrating deorbiting and active propulsion systems. Developers should be mindful of the potential impact of ISED’s proposed regulations on CubeSats, as well as the relatively strict requirements compared to other jurisdictions. To navigate the challenges this may present, it is recommended that the development of CubeSat-appropriate deorbiting and maneuvering systems be supported, more flexible and tiered deorbiting guidelines be implemented, and clear, easily accessible compliance criteria be provided. These strategies could play a crucial role in mitigating the heavy burden proposed on developers of small, yet invaluable, satellites that enhance Canadians’ understanding of their country and the world each day.

Endnotes