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A Guide for Understanding and Assessing U.S. Space Sustainability Initiatives
Dr. Michel P. Gleason, National Security Senior Project Engineer, The Aerospace Corporation’s Center for Space Policy and Strategy


In the last few years, the United States has taken significant steps forward in establishing a framework for protecting the sustainability of the space domain and in demonstrating U.S. leadership and commitment to preserving the safety, stability, security, and long-term sustainability of space activities.

The framework is implicit in the first ever U.S. National Space Traffic Management Policy, Space Policy Directive-3 (SPD-3),which is re-emphasized and promoted in the December 2020 U.S. National Space Policy (NSP).2 This paper identifies key lines of effort, extrapolated from SPD-3 and reinforced in the 2020 NSP, to guide understanding and assessment of recent efforts, and provides insights into where new and continuing efforts should be focused.

Figure 1: Growth in commercial GS constellations – number of satellites per FCC filings since October 2012 (logarithmic scale).

Population Explosion in Space

Since the Space Age began more than 60 years ago, about 9,800 satellites have been placed in orbit with about 6,700 still there, and as of March 2021 about 3,100 of those are still operating.3 In 2019, several commercial companies proposed satellite constellations ranging from potentially 1,000 to 30,000 satellites each, totaling 75,000 or more new satellites in orbit for a single generation.

The number of proposed satellites changes nearly every day with some recent estimates reaching more than 100,000 additional satellites in orbit by 2030. This anticipated rise in the number of satellites in such a short period of time will lead to a significant increase in collision risk. The resulting space debris, along with the new vehicles themselves, will challenge the overall sustainability of the space environment. 

While it is unlikely that all of the planned satellites will be launched, Figure 1 illustrates that almost 2,000 new commercial satellites have been placed in non-geostationary orbits (NGSO) since 2012 and the upward trend continues to accelerate.

*The United States is beginning to address the fundamental changes occurring in the space environment.

U.S. Government Orbital Debris Mitigation Standard Practices

Among its top priorities, SPD-3 called for an update to the U.S. Government Orbital Debris Mitigation Standard Practices (USG ODMSP) from the year 2000. The standard practices apply to all U.S. government organizations involved in space operations and serve as the U.S. government’s foundation for issuing specific orbital debris mitigation requirements and technical guidance.

Furthermore, the Federal Communications Commission (FCC), Federal Aviation Administration (FAA), and National Oceanic and Atmospheric Administration (NOAA), three U.S. space regulatory agencies, mandated the compliance of U.S. private spacecraft companies with agency or commission regulations based on USG ODMSP.

The 2000 USG ODMSP aimed to limit the amount of orbital debris and the amount of time that such debris and spacecraft could remain in orbit. The standard practices include all spacecraft program phases, from concept development to space hardware disposal. SPD-3 highlighted the need to update the USG ODMSP “to enable more efficient and effective compliance and establish standards that can be adopted internationally.”

In December 2019, 18 months after SPD-3 was published, the U.S. government released its new Orbital Debris Mitigation Standard Practices.4 The 2019 update, a U.S. whole-of-government effort led by the National Aeronautics    and    Space    Administration (NASA), introduced operating practices for emerging space activities—including large constellations and smallsat (including cubesat) operations, rendezvous and proximity operations (RPO), active debris removal operations (ADR), and satellite servicing.

It also introduced quantitative limits on debris released during normal operations, probability limits on accidental explosions and collisions with large and small debris, and a reliability threshold for post-mission disposal.

In addition, the new ODMSP includes preferred and new end-of-mission-life disposal and storage options for structures in Low Earth Orbit (LEO), Medium Earth Orbit (MEO), Geosynchronous Orbit (GEO), inclined GEO orbits, Highly Elliptical Orbits (HEO), and other orbits to minimize the impact on future space operations.

Nevertheless, many observers viewed the update as modest given the dramatic rise in the number of satellites projected to be placed in orbit.5

Many were disappointed that the 2019 USG ODMSP did not change the previous ODMSP guideline recommending that satellite operators remove spacecraft and orbital stages from useful and densely populated orbit regions no longer than 25 years after mission completion, colloquially referred to as the “25-year rule.”

Many observers advocate for reducing the time frame to under 25 years, even though compliance rates with the current 25-year standard are poor.6 These observers argue that the current approach will not scale to the expected increases from satellite constellations consisting of hundreds or thousands of satellites.7

Nor does the  current  approach account for the short mission lives of cubesats, which represent a growing sector of the satellite industry.

Other observers argue that the effect on the debris environment of shorter lifetimes is relatively small, and the new USG ODMSP’s addition of a 90 percent or better post-mission disposal requirement addresses the lack-of-compliance issue by making the success rate an active consideration.

The 2020 NSP states that the United States shall periodically update the USG ODMSP, but it is unclear how often that will occur. Given the rapidly changing space environment, the debates surrounding the 25-year rule and measures for managing large numbers of satellites are likely to continue and ideally the USG ODMSP will be updated more frequently than the previous 20 years between updates.

U.S. International Leadership

The coming few years will also show if the 2019 USG ODMSP follows a similar path as the 2000 USG ODMSP to wide international acceptance. The 2000 USG ODMSP influenced the development of the 2002 Inter-Agency Space Debris Coordination Committee (IADC) Space Debris Mitigation Guidelines, which in turn influenced the United Nations (UN) Committee on the Peaceful Uses of Outer Space (COPUOS) Space Debris Mitigation Guidelines8

Today, the 13 IADC-member agencies have, to various extents, incorporated these debris mitigation standards into their domestic regulation and law.†

SPD-3 endorsed development of congruent international approaches to minimize debris and called for the United States to promote the USG ODMSP as a model for consideration in international forums such as IADC, International Organization for Standardization (ISO), and COPUOS.

The 2020 NSP establishes policy consistent with this approach as well. The United States was successful in following this approach and could continue to lead the rest of the world forward along this proven path. And with an increased sense of urgency, the United States could benefit by promoting the 2019 USG ODSMP in the IADC and in COPUOS.

In addition, the 2020 National Space Policy and SPD-3 call for U.S. leadership in the development of international and industry standards that will help preserve the space environment through organizations such as the ISO.

As the most important of the ISO space debris mitigation standards, ISO Standard 24113 represents another line of effort in which momentum should be maintained. ISO Standard 24113 was updated in July 2019, with several revisions including important updates to the probability of successful post-mission disposal.9 The probability is now calculated from the beginning of the mission rather than from just before disposal.

Also, the required success rate is at least 90 percent, which is in line with the 2019 ODMSP, which was taken from NASA Standard 8719.14 and AFI 91-217 (now in AFI 91-202). While ISO 24113 remains the primary debris mitigation standard, two additional standards — ISO 20893, which was completed in March 2021, and ISO 23312, which is under development — will be new supporting standards for 24113. It is likely that revisions to ISO 24113 will begin well before the standard review cycle with a goal of synchronizing development of the related debris mitigation standards.10

The United States could benefit by continuing to encourage development of these new standards on an accelerated timeline.

SPD-3 and the NSP also encourage the international adoption of guidelines and best practices for safe space operations through U.S. participation in COPUOS. In June 2019, COPUOS achieved consensus among 92 countries (including Russia and China) and adopted a set of 21 voluntary “Guidelines for the Long-term Sustainability of Outer Space Activities” (also known as LTS guidelines).11

In adopting the guidelines, the committee agreed to establish a follow-on working group for 2020 through 2024 to examine issues associated with implementation, capacity building, and possible new guidelines.

However, the formation of this “LTS 2.0” working group has been slowed by COVID-19 and continued efforts by Russia to inject disarmament-motivated proposals (such as a guideline for non-cooperative rendezvous and proximity operations) which exceed COPUOS’s longstanding mandate to address “bottom up” measures for spaceflight safety.

The United States and like-minded nations continue to encourage Russia in COPUOS to agree to the follow-on LTS working group or at least not stand in its way.

Space Traffic Management.

Perhaps the most ambitious line of effort in SPD-3, and reinforced in the NSP, is transitioning civil Space Situational Awareness (SSA) and Space Traffic Management (STM) service responsibilities from the Department of Defense (DoD) to the Department of Commerce (DoC).

In December 2020, Congress approved this course of action in law, and directed the DOC Office of Space Commerce (OSC) to initiate a STM pilot program and an Open Architecture Data Repository (OADR) pilot project. Congress provided increased appropriations to the DOC/ OSC in fiscal year 2021, marking a significant increase in funding compared to the appropriations OSC received in previous years. Despite its constrained budget, however, DOC/OSC has been making progress since 2018 in establishing the OADR.

SPD-3 also calls for research and development to support such SSA and STM capabilities and applications saying, “These activities include improving fundamental knowledge of the space environment, such as the characterization of small debris, advancing the science and technology of critical SSA inputs such as observational data, algorithms, and models necessary to improve SSA capabilities, and developing new hardware and software to support data processing and observations.”12

The January 2021 National Orbital Debris Research and Development (R&D) Plan answers that call by providing a national plan to coordinate and prioritize research and development into managing the risk posed by orbital debris. The plan calls for continued coordination and discussion among the interagency, private industry, academia, and international partners.

As the national space debris R&D plan evolves, it will help close critical technical gaps in understanding the debris environment and the capabilities needed to protect space sustainability.13

Rules and Regulations

Separate and distinct from the NSP and SPD-3 mandates, on October 25, 2018, the FCC released the “Notice of Proposed Rulemaking  and Order on Reconsideration, IB Docket No. 18-313.” Importantly, the FCC is an independent agency, not under the authority of the executive branch of the U.S. government as DoC is. The notice sought comments from the public on proposed updates to the orbital debris mitigation rules for all FCC- authorized satellites.

As noted above, the FCC mandates that U.S. private spacecraft companies comply with debris mitigation rules that are based on the USG ODMSP in order to obtain FCC licensing. The proposed update offered many potential new regulations—for example, new rules regarding space object trackability, information sharing requirements, orbit selection, post-mission disposal reliability, and dozens of other technical and operational requirements.

However, this FCC rulemaking effort highlighted the natural tension that exists between the government’s need for regulation to protect the safety, security, and sustainability of the space environment and industry’s desire for minimal, clear, and consistent regulatory constraints.

While most space industry players acknowledge the importance of orbital sustainability, increasing regulatory constraints on space activities could increase design and operational costs, frustrate commercial innovation, and discourage venture capital investments.

On April 2, 2020, the FCC released a draft of revised orbital debris mitigation regulations and the tensions noted above came to the forefront. The draft rules included stringent new requirements for operators applying for an FCC license and U.S. market access to indemnify the  government for damage their satellites might cause; to be bonded for up to $100 million, which would be forfeited if operators did not properly dispose of the satellites; and to design spacecraft flying above 400 kilometers to be maneuverable in order to avoid collisions above that altitude.

These strict new rules were opposed by industry, Congress and others as being detrimental to U.S. space companies and for putting the U.S. space industry at a competitive disadvantage compared to other countries.14

On April 23, 2020, in the face of this opposition, the FCC voted unanimously in favor of requiring satellite operators to quantify their collision risk, probability of successfully disposing spacecraft, and the casualty risk associated with spacecraft that reenter Earth’s atmosphere, but deferred consideration of the more controversial draft rules until they could be studied further.15

Soon thereafter, the FCC issued a “Further Notice of Proposed Rulemaking” (FNPRM) and began a new round of public comment on the unresolved issues.

Final public comments on this new FNPRM were due to the FCC in October 2020. An additional set of draft rules will be generated based on consideration of the additional comments from industry and government.

Congress and other stakeholders could benefit from following the development of these draft FCC rules and evaluate their alignment with the other lines of effort outlined above. 

These various lines of effort toward establishing a new framework for protecting the sustainability of the space environment, as directed in SPD-3 and reemphasized in the NSP, and through the independent initiatives of the FCC, show progress is being made in response to the rapid changes in space activities.

Observers should expect to see continued momentum by the United States along these lines of effort.

Conclusion SPD-3 drove steady, incremental progress over the last few years toward establishment of a new framework for protecting the sustainability of the space domain, and the U.S. government has outlined the way ahead domestically and internationally as reflected in Table 1.

As the new U.S. administration and Congress chart the course for U.S. space leadership, they should find that the 2019 USG ODMSP is now in place to help the United States promote new approaches for orbital debris mitigation in international forums like the IADC and COPUOS, and to inform future revisions to ISO 24113.

In addition, the COPUOS follow-on working group for LTS guidelines indicates that multilateral efforts to promote sustainability guidelines hold promise but may need a push to overcome the obstacles presented by Russia.

While the DoC space traffic management line of effort matures, expect  to see lessons learned from its STM pilot program. Likewise, as orbital debris R&D becomes better coordinated and prioritized, improved knowledge of orbital debris should lead to new understanding and advanced capabilities.

As new FCC rules emerge, stakeholders may evaluate their alignment with the NSP and SPD-3.

Assessing these lines of effort, extrapolated from SPD-3 and the 2020 NSP, provides insight into where efforts going forward could focus in order for the United States to demonstrate and maintain global leadership and protect the sustainability of space activities.

* See the Annex, “Proposed, Approved, and Deployed Satellite Constellations,” for more detailed numbers.

† IADC member agencies include ASI (Agenzia Spaziale Italiana), CNES (Centre National d’Etudes Spatiales), CNSA (China National Space Administration), CSA (Canadian Space Agency), DLR (German Aerospace Center), ESA (European Space Agency), ISRO (Indian Space Research Organisation), JAXA (Japan Aerospace Exploration Agency) KARI (Korea Aerospace Research Institute), NASA (National Aeronautics and Space Administration), ROSCOSMOS (State Space Corporation), SSAU (State Space Agency of Ukraine), and the UK Space Agency


1 Presidential Memoranda, Space Policy Directive-3, National Space Traffic Management Policy (SPD-3), Infrastructure and Technology, June 18, 2018. [Hereafter “SPD-3, 2018.”] (https://www. federalregister.gov/documents/2018/06/21/2018-13521/national- space-traffic-management-policy).
2 Presidential memoranda, The National Space Policy, December 9, 2020. [Hereafter “NSP, 2020.”] (https://www.federalregister.gov/ documents/2020/12/16/2020-27892/the-national-space-policy).
3 Interviews with Marlon Sorge and Grant Cates, The Aerospace Corporation, March 2020. 4 U.S. Government Orbital Debris Mitigation Standard Practices, November 2019 Update (https://orbitaldebris. jsc.nasa.gov/library/usg_orbital_debris_mitigation_standard_ practices_november_2019.pdf)
4 U.S. Government Orbital Debris Mitigation Standard Practices, November 2019 Update (https://orbitaldebris.jsc.nasa.gov/ library/usg_orbital_debris_mitigation_standard_practices_ november_2019.pdf).
5 Jeff Foust, “U.S. government updates orbital debris mitigation guidelines,” SpaceNews, December 9, 2019 (https://spacenews. com/u-s-government-updates-orbital-debris-mitigation-guidelines/)
6 “ESA’s Annual Space Environment Report,” ESA Space Debris Office, Issue/Revision 3.2, July 17, 2019
7 Rebecca Reesman et al, Slash the Trash: Incentivizing Deorbit, April 2020 (https://aerospace.org/paper/slash-trash-incentivizing- deorbit)
8 Committee on the Peaceful Uses of Outer Space, Legal Subcommittee, Compendium of space debris mitigation standards adopted by States and international organizations: Contribution of the United States of America, March 25, 2014
9 ISO 24113:2019 Space systems — Space debris mitigation requirements (https://www.iso.org/standard/72383.html
10 Interview with Marlon Sorge, June 2020
11 United Nations Report of the Committee on the Peaceful Uses of Outer Space Sixty-second Session, A/74/20, V.19-06077, 12–21 June 2019 (https://www.unoosa.org/res/oosadoc/data/ documents/2019/a/a7420_0_html/V1906077.pdf)
12 SPD-3, 2018
13 The National Science and Technology Council (NSTC), National Orbital Debris Research and Development (R&D) Plan, January 2021 (https://trumpwhitehouse.archives.gov/wp-content/uploads/2021/01/National-Orbital-Debris-RD-Plan-2021.pdf).
14 Jeff Foust, National Space Council in discussions on FCC orbital debris policies, SpaceNews, May 7, 2020 (https://spacenews.com/ national-space-council-in-discussions-on-fcc-orbital-debris-policies/).
15 Caleb Henry, FCC punts controversial space debris rules for extra study, SpaceNews, April 23, 2020 (https://spacenews.com/fcc-punts- controversial-space-debris-rules-for-extra-study/).

Author Dr. Michael P. Gleason is a national security senior project engineer in The Aerospace Corporation’s Center for Space Policy and Strategy and is a well-regarded author on space policy subjects, including international cooperation, space traffic management, national security, and deterrence. He has presented his research on critical space policy issues at conferences in Canada, Europe, Japan, and across the United States. A graduate of the U.S. Air Force Academy, Gleason served 29 years active in the Air Force space career field, including stints in spacecraft operations, on the Air Force Academy faculty, at the Pentagon, and at the Department of State.

He holds a Ph.D. in International Relations from George Washington University (GWU) and is an alumnus of the GWU Space Policy Institute. Gleason is the recipient of the Defense Superior Service Medal and the Department of State Superior Honor Award.

The Center for Space Policy and Strategy is dedicated to shaping the future by providing nonpartisan research and strategic analysis to decision makers. The Center is part of The Aerospace Corporation, a nonprofit organization that advises the government on complex space enterprise and systems engineering problems. The views expressed in this publication are solely those of the author(s), and do not necessarily reflect those of The Aerospace Corporation, its management, or its customers.

For more information, go to www.aerospace.org/policy or email policy@aero.org. © 2021 The Aerospace Corporation. All trademarks, service marks, and trade names contained herein are the property of their respective owners.

Permission to republish this article in MilsatMagazine received from the The Aerospace Corporation.