Why a good-enough STM approach is better than perfect
Whatever space traffic management framework emerges — assuming something more formal ever does — it will be far from perfect. No traffic management framework in any domain eliminates accidents. Unintentional collisions in space will happen.
Space traffic management (STM) should be about mitigating risk, not eliminating it. Nor should there be any expectation that the U.S. Office of Space Commerce and its Open Architecture Data Repository will prevent all accidents. The law of diminishing returns tells us that any STM framework will only mitigate the risk of collisions to the point where greater and greater resources are required for only incremental gains in risk reduction. Given that resources are limited and an STM framework only mitigates part of the overall risk to space sustainability, the U.S. government should focus on leading a prudent risk-reduction approach to space sustainability that includes space debris management (SDM) efforts – that is, the mitigation and remediation of space debris. The most practical approach to space sustainability is to pursue a “good enough” risk-reduction strategy across STM and SDM efforts where the residual risk to space sustainability becomes manageable — not perfect.
There are only two solutions to assure zero collisions in space and eliminate all risk: conduct zero activity in space (too late) or significantly limit new activity in space and create a highly restrictive and controlled STM framework. Neither option is practical nor acceptable. In reality, space activity is rapidly growing and if society values that activity, society has to accept the risk that comes with it. Improving the STM framework will mitigate some of this growing risk, but not eliminate it, even if the international community pursues the ideal STM framework with unlimited resources.
Consider the reality of every other traffic management framework in other domains. Despite robust automotive safety standards and traffic regulations in the United States, tens of thousands of vehicle collisions occur every year. In the maritime domain, hundreds of accidental collisions occur out at sea every year despite centuries of experience and the institutionalization of the International Regulations for Preventing Collisions at Sea. In aviation, despite strict air traffic control and the high regard for human safety, several mid-air collisions have occurred since 2000. Even with state-of-the-art technologies and decades or even centuries of experience, traffic management frameworks can only mitigate risk, not eliminate it.
Arguably, the U.S. air traffic management framework has an impeccable reputation as of late, illustrating its utility as a model for STM. However, the high degree of safety in air traffic has undoubtedly been at the expense of efficiency. The length of U.S. flight delays increased 69% between 2012 and 2017, The Economist magazine reported in 2019. China saw a similar trend. In Europe, flight delays and cancellations cost the economy over $20 billion in 2018, according to Eurocontrol. Emulating a similar system for space traffic management would likely entail similar implications that the space industry must be willing to accept.
In addition to inefficiency, the applicability of an air traffic model to STM suffers from an unrealistic international government capacity to strictly control space traffic in both size and scope. For example, as commercial air activity expands to upper E-class and lower C-class air space, the FAA has essentially indicated they do not have the capacity to manage those altitudes — both from a cost and a capabilities perspective. Attempting to effectively control all orbital activity at a level that prevents all collisions would likely require significant capabilities that come with exorbitant costs, not to mention the infeasibility of overcoming the existing geopolitical barriers to create such an international framework.
An STM framework also significantly diverges from other traffic management models, particularly the air traffic model, because space is not a self-healing environment above very low orbital altitudes. When an airplane has a mechanical issue and crashes, like the China Eastern Airlines Flight 5735 in March, it does not affect other air traffic activities. However, when a perfectly operating satellite becomes defunct, it becomes a significant hazard that no perfect STM framework could completely mitigate. The dangers are multiplied if the satellite fragments.
A good-enough STM framework can still mitigate a significant amount of collision risk, but only if accompanied by a good-enough SDM framework (which is currently lagging far behind where it needs to be). Space traffic management and space debris management work together to reduce the aggregate risk to space sustainability. Given this approach to space sustainability risk management, the U.S. government should pursue a trifurcated space sustainability plan similar to what the Secure World Foundation’s Brian Weeden urged Congress to pursue in his February 2020 testimony to the House Science space and aeronautics subcommittee.
The U.S. government must pursue a more formal national STM framework that rapidly implements Space Policy Directive-3 (SPD-3), issued by the president in 2018. In addition, it must expand on limited, but sufficient, regulatory requirements to account for the unanticipated rapid rise of megaconstellations and the unrelenting growth of private investment in the space industry.
For example, similar to Rule 7 of the International Regulations for Preventing Collisions at Sea, a licensing or rule requirement for satellite operators to anticipate risk, proactively mitigate it, and take sufficient steps to avoid a collision from occurring – something most of the commercial space industry already practices – would significantly reduce risk by creating greater predictability and clarity.
Further, efforts toward this national STM framework significantly reduce collision risk for three reasons:
- It can emerge much faster than an international approach;
- It would apply to well over half the operational satellites in orbit (because they are under U.S. jurisdiction);
- It would serve as an effective safety model for other nations to emulate, ultimately facilitating a viable pathway toward an international STM framework.
The U.S. government must pursue SDM efforts, particularly space debris remediation, more rapidly than SPD-3 indicates. Despite SPD-3 indicating the development of active debris removal (ADR) efforts as a long-term approach, the U.S. government should initiate efforts now. However, it should pursue space debris remediation in collaboration with existing efforts by the European Space Agency, the Japan Aerospace Exploration Agency, and the U.K. Space Agency (UKSA). All three space agencies have a head start on the United States.
Developing ADR capabilities now ensures that when the limits of an STM framework become evident and collisions inevitably happen, there will be sufficient ADR capacity to conduct post-collision cleanup efforts. In the meantime, ADR capabilities can further reduce the aggregate risk to space sustainability by removing the large rocket bodies and other high-risk derelict objects that pose a considerable risk for further space debris generation.
In either case, there must be deliberate efforts to develop space remediation efforts now. The U.S. government can help spur existing efforts by committing its support.
As part of an SDM effort, space debris mitigation is still important. The U.S. government should again revise the Orbital Debris Mitigation Standard Practices (ODMSP). The revision of the ODMSP in 2019 following SPD-3’s guidance was underwhelming and not merely sufficient for the emerging space traffic and debris challenges. However, as the satellite operators meet the current standards and goals, the U.S. government should periodically revise ODMSP with incremental standards as existing ones become more attainable. For example, modifying post-mission disposal time-frames to five or 10 years or increasing the success rate of doing so from 90% to 91% – both of which the commercial space industry is already striving toward.
All three efforts are necessary to reduce the aggregate risk to space sustainability. The key is to mitigate the biggest risks in each of these efforts. It’s the most practical, feasible, and attainable way forward. It also sets the conditions for further risk mitigation efforts in STM and SDM.
Some may characterize this risk management approach as cynical or point out that space collisions will trigger an international STM effort anyways. However, history indicates otherwise. After the 2009 Iridium-Cosmos collision, the primary safety measures were unilateral U.S. military improvements on its screening and notification procedures for conjunction assessments and its SSA sharing program. Further, despite the rapid rise of close approaches and potential collisions between space objects and the growing need for commercial SSA and STM service providers, such as LeoLabs, COMSPOC, ExoAnalytics and others, no prominent international space sustainability program has gained traction.
Another concern is that space remediation efforts, such as active debris removal, will detract from space risk mitigation and STM efforts and further enable consequence-free testing of anti-satellite weapons. However, as John Klein points out in his book, Understanding Space Strategy, clearing debris would still be no easy task. It would require extensive time and effort to methodically clear the affected area, similar to clearing mines from high-traffic areas.
The good-enough STM approach does not view routine collisions as acceptable but accepts that a few are inevitable due to the growing activity in space. Presenting the challenge to space sustainability from this perspective shapes it into a problem that can be solved with a commitment from the United States, both as a leader and a member of the international community.
STM and space debris mitigation efforts serve as key avenues for the United States to maintain its space leadership and align with the Biden administration’s U.S. Space Priorities Framework, released in December 2021. In addition, space debris remediation efforts serve as a key avenue for the United States to demonstrate its willingness to be a team player in the international community while supporting and contributing to the achievements other nations have already attained with ADR capabilities.
The United States must pursue a good-enough risk reduction strategy across STM and SDM efforts where the residual risk to space sustainability becomes manageable. There is no perfect STM framework, no perfect debris mitigation effort, and no perfect debris remediation effort. However, there can be a practical space sustainability framework that preserves the usefulness of space for future generations and allows us to maximize the utility of space today for humankind. We must not let the pursuit of perfect be the enemy of the good enough.
Benjamin Staats is a graduate student at George Washington University’s Space Policy Institute, a U.S. Army space operations officer and a Schriever Space Scholar Graduate from the U.S. Air Force Air Command and Staff College. The views expressed are those of the author and do not reflect the official policy or positions of the Department of Defense or the U.S. Army.
This article originally appeared in the June 2022 issue of SpaceNews magazine.