Publications by Christopher D. Johnson

Christopher D. Johnson, Space Law Advisor of Secure World Foundation (read bio)

Articles

• "Echostar-7: The US Imposes First-Ever Fine for Failure to Comply with Deorbiting Plan," Article, Air and Space Law, Mar 7, 2024.
• "Book Review: War and Peace in Outer Space: Law, Policy, and Ethics," Air & Space Law 47, no. 1 (2022): 135–140., January 2022
• "Debris-creating Anti-satellite Weapons and Their Indiscriminate Effects," NATO Legal Gazette, Issue 42, December 2021
• "Space Debris Peril: Pathways to Opportunities – Capacity Building in the New Space Era (Book Review)," Air & Space Law 46, no. 4&5 (2021): 643–648. © 2021 Kluwer Law International BV, The Netherlands, Sep 1, 2021.
• "Op-ed | Building Back Better: Critical first issues for a successful Biden space policy," By Krystal Azelton, Ian Christensen, Chris Johnson, Victoria Samson, and Brian Weeden, Space News, Dec 4, 2020.
• "Renewed Ambitions in Space-Exploration Lawmaking," The Air & Space Lawyer, Volume 33, Number 3, 2020. © 2020 by the American Bar Association., Sep 1, 2020.
• "#SpaceWatchGL Feature: The Space Law Context Of The Artemis Accords," SpaceWatchGlobal, May 27, 2020.
• "#SpaceWatchGL Perspective On US Space Resources Executive Order: Christopher Johnson On How The U.S. Seeks To Be A Pioneer In Space Resources Norm Development," SpaceWatch.Global, Apr 28, 2020.
• "Insight – Developing Norms of Behavior for Space," Secure World Foundation Newsletter (February 2020), Feb 5, 2020.
• "The curious case of the transgressing tardigrades (part 3)," by Christopher D. Johnson, Daniel Porras, Christopher M. Hearsey, Sinead O’Sullivan, and Monica Vidaurri, The Space Review, Sep 16, 2019.
• "The curious case of the transgressing tardigrades (part 2)," The Space Review, Sep 3, 2019.
• "The curious case of the transgressing tardigrades (part 1)," by Christopher D. Johnson, Daniel Porras, Christopher M. Hearsey, and Sinead O’Sullivan, The Space Review, Aug 26, 2019.
• "Secure World Foundation (SWF) Insights: Avoiding conflict in outer space," MilsatMagazine, July/August 2019
• "What is allowed in outer space?," Oxford University Press Blog's Academic Insights for the Thinking World, Mar 30, 2018.
• "Outer Space Treaty," in Oxford Research Encyclopedia of Planetary Science, Oxford University Press, Article published January, 2018: doi: 10.1093/acrefore/9780190647926.013.43
• "A summer update on the COPUOS long-term sustainability guidelines," The Space Review, Jul 24, 2017.
• "The 59th Colloquium on the Law of Outer Space at the 67th International Astronautical Congress," Air and Space Law, Vol. 42, No. 1, Feb. 2017.
• "The Outer Space Treaty at 50," The Space Review, Jan. 23, 2017.
• "Outer Space: Ungoverned or Lacking Effective Governance?," New Approaches to Managing Human Activities in Space, The SAIS Review of International Affairs, Vol. 36, No. 2, Dec. 2016.
• "The Importance of the United Nations Guidelines for the Long-Term Sustainability of Space Activities and other International Initiatives to Promote Space Sustainability," OASIS, Vol. 20, July-Dec. 2014.
• "Secure World Foundation Event Explores the Evolving Role of Satellites in Aviation Safety," Space Safety Magazine, May 15, 2014.
• "The Texas Space Flight Liability Law & Efficient Regulation for the Private Commercial Space Flight Era," Acta Astronautica--Special Issue - 2nd IAA Symposium on Private Human Access to Space, Dec. 2013 Vol. 92, Issue 2.
• "How Space Can Contribute to Africa's Development," (Co-Author), Space Times Magazine, May/June 2013 Vol. 52, Issue 3.

Papers / Reports

• "2020 Wrap Up Policy Recommendations: A Moon Dialogs Report – Dec 2020," published jointly by Moon Dialogs conveners
• "Moon Dialogs Recap: Voices of the Community - Dec 2020," published jointly by Moon Dialogs conveners
• "Summary Report: Norms of Behavior In Space Workshop," Feb 3, 2020.
• "Reality and clarity in understanding the prohibition on national appropriation in article II of the outer space treaty," IAC-15-D4.3.13, presented at the 66th International Astronautical Congress, Jerusalem, Israel, Oct 12, 2015.
• "Mars Treatymaking Workshop Results and Insights from ISU SSP15," IAC-15-E1.4.2, presented at the 66th International Astronautical Congress, Jerusalem, Israel. With Jessica M. Reinert, Marius Berge Eide, Rémi Gourdon, Valentina Boccia, and Michael Davis, Oct 12, 2015.
• "How Simple Terms Mislead Us: The Pitfalls of Thinking about Outer Space as a Commons," October 12-16, 2015 IAC-15-E7.5.2, presented at the 66th International Astronautical Congress, Jerusalem, Israel. With Henry Hertzfeld.
• "Transparency and Security Assurances for Commercial On-Orbit Servicing," (Co-Author), Manfred Lachs Conference on Conflicts in Space and the Rule of Law, Montreal, Canada, March 2015.
• "Legal Aspects of the ISECG Non-Binding Coordinating Mechanism," 64th International Astronautical Congress, 56th IISL Colloquium on the Law of Outer Space, Joint IAF/IISL Session on Legal Framework for Cooperative Space, Proceedings of the International Institute of Space Law 2013, Sep 27, 2013.
• "The Space Assets Protocol: A Look Ahead," 2013 IISL - ECSL Space Law Symposium on the Cape Town Convention and the Space Assets Protocol, Apr 8, 2013.
• "Desert Movement Predictor and Farmabooths: Two Earth Observation Based Applications for Pan-African Development," 63rd International Astronautical Congress, Naples, Italy. With R. Topham, M. Ebert, S. Georgakas, R. Villatoro, H. Modi, and J. Osborne., Feb 19, 2013.
• "GNSS and SBAS System of Systems: Considerations for Applications in the Arctic," 63rd International Astronautical Congress, Naples, Italy. With T. Sundlisaeter, T. Reid, S. Wan., Oct. 3, 2012.
• "National Space Legislation for Emerging Space Capable Nations," 63rd International Astronautical Congress, Naples, Italy. With J. Chatterjee and A. Puścińska., Oct 2, 2012.
• "Assisting Development Across the African Continent Using Space Applications," 63rd International Astronautical Congress, Naples, Italy. With J. Osborne, M. Ebert, S. Georgakas, R. Villatoro, H. Modi, and R. Topham., Oct 1, 2012.
• "An Interdisciplinary Approach to Human-Robot Cooperation in Near-Term Exploration Scenarios," Global Space Exploration Conference, Washington, D.C. With J. Osborne, C. Brunskill, R. Jaguste, H. Sharif, I. Silversides, B. Trey, and M. Vlasea., May 25, 2012.
• "Emerging Issues, Existing Law, and Pragmatic Solutions," Global Space Exploration Conference, Washington, D.C., May 24, 2012.
• "Identifying and Developing Effective Applications of Space for Africa," May 1, 2012.
• "An Interdisciplinary Approach to Human-Robotic Cooperation in Mars Exploration," An Interdisciplinary Approach to Human-Robotic Cooperation in Mars Exploration AC-11-A5.3.B3.6, International Astronautical Conference, October 6, 2011. With D. Evensberget, C. Brunskill, M. McCrum, J. Osborne, B. Weiss, K. Eriksson, R. Ewald., Oct 6, 2011.
• "CHARM: Cooperation of Humans and Robots for Mars," (Co-Author and Main Editor), ISU Space Studies Team Project on Human-Robotic Cooperation Final Report., 3 Sep. 2011.
• "Financing for Commercial Space - Asset-Backed Financing, International Space Law, and the UNIDROIT Draft Protocol on Space Assets," Leiden University, International Institute of Air and Space Law, Aug 10, 2010.

Books

• "Lunar Policy Handbook," Apr 14, 2023.
• "Handbook for New Actors in Space," 2017 Edition.

Book Chapters

• "Routledge Handbook of Commercial Space Law," Commercial space activities in the US: An overview of the current policy and regulatory framework, Jul 31, 2023.
• "Chapter 13: International Law Governing Outer Space Activities," Outer Space Law: Legal Policy and Practice, Second Edition, April 2022
• "The Law of Outer Space: A Self-Contained Regime?," Fifty Years of Space Law - Cinquante ans de droit de l'espace, Editors: Philippe Achilleas, and Stephan Hobe, 2020
• "The Legal Status of MegaLEO Constellations and Concerns About Appropriation of Large Swaths of Earth Orbit," In: Pelton J. (eds) Handbook of Small Satellites. Springer, Cham, Mar 5, 2020.
• "Space Sustainability," CRC Press Taylor & Francis Group, Richard J. Wilman & Christopher J. Newman, Editors, Frontiers of Space Risk: Natural Cosmic Hazards & Societal Challenges, Jun 15, 2018.
• "International Law Governing Outer Space Activities," Globe Law and Business Publishers, Yanal Abul Failat & Anel Ferreira-Snyman, Editors, Outer Space Law, Legal Policy and Practice, Oct 1, 2017.
• "Legal And Regulatory Considerations," McGraw-Hill Space Technology Series, CEI Publications, Wiley Larsen, Ran Qeder & Victoria Alnsoperez, Editors, Guidebook On Small Satellite Projects, Apr. 1, 2014.
• "The Space Assets Protocol - A Look Ahead," United Nations 2013 IISL-ECSL Space Law Symposium, 52nd Session of the Legal Subcommittee of UNCOPUOS Vienna, Austria, chapter in, Proceedings of the International Institute of Space Law 2013, 2013
• "Policy & Law Aspects of International Cooperation in Space," 62nd International Astronautical Congress, 54th Colloquium on the Law of Outer Space, Joint IAF-IISL Session on Policy and Law of Human Space Missions, chapter in, Proceedings of the International Institute of Space Law 2011, 2012.
• "Policy and Law Aspects of International Cooperation in Space," 62nd International Astronautical Congress, 54th Colloquium on the Law of Outer Space, Joint IAF-IISL Session on Policy and Law of Human Space Missions, Oct 1, 2011.

Presentations

• "State Responsibility and Liability," Nov 6, 2023.
• "Discussing the Increasingly Hostile Space Environment and Exploring How Belligerent Actors Could Impact SATCOM Infrastructure," Panelist at GlobalMILSAT Conference, Nov 6, 2023.
• "Legal and Policy Aspects of Planetary Defense," Apr 8, 2023.
• "Stressors on International Cooperation and Coordination in NEO Threat Mitigation & Response," 8th Meeting of the Outer Space: 8th IAA Planetary Defense Conference, Apr 6, 2023.
• ""Space Law Fundementals,"" Presentation delivered at University of Georgia School of Law, Jan 20, 2023.
• "'As Brothers and Not Warriors on the Moon' - Safety Zones on the Moon," IAC Paris - IISL Colloquium, Sep 14, 2022.
• "The policy aspects concerning sustainable lunar exploration vis-à-vis the exploitation of lunar resources for commercial and/or scientific purposes," Keynote Presentation, International Moon Day 2022 (hosted by the Moon Village Association - India), Jul 17, 2022.
• "Making the Moon Work: Governance and Safety in a New Environment," Panel, 4th Summit for Space Sustainability, Jun 24, 2022.
• ""Space Law and the Moon,"" LSIC Lunar Panel at Johns Hopkins University, May 4, 2022.
• "Christopher Johnson presents "International Law in Space" at Northern Illinois University," Apr 8, 2022.
• ""Space Law, Politics, + Sustainability" Presentation from Chris Johnson," Mar 8, 2022.
• ""Space Law Brownbag" for Masten Aerospace," Feb 11, 2022.
• "Consultant for the U.S. Department of State on Space Issues (Private Briefing)," September 2021
• "Legal Aspects of Space Debris," presented at "Conversations For The Future: Space Garbage, Recycling, & Sustainability" hosted by Foundation for the Future, September 8-9, 2021
• "Secure World Foundation Statement Under Agenda Item 4 - General Exchange of Views," presented during the 64th session of the United Nations Committee on the Peaceful Uses of Outer Space, Sep 1, 2021.
• "Space Mining The High Frontier (Conference)," Hosted by SpaceTech Analytics, Jul 28, 2021.
• "SG[Egypt] - Egypt's Next Frontier," Lunar Exploration Panel, Hosted by the Space Generation Advisory Council (SGAC), Jul 10, 2021.
• "Megaconstellations: The Train Has Left the Station. Now What?," Panel, 3rd Summit for Space Sustainability, Jun 22, 2021.
• "Space Policy, Law and Society (Panel)," 6th South America Space Generation Workshop, Apr 11, 2021.
• "Cooperation, Coordination and Competition in Outer Space," presented to the United Nations Association of the United States of America - Southwest Connecticut, Mar 4, 2021.
• "Webinar: The Great Game of Economics Afoot in Space," organized by NewSpace NewMexico (Panelist), Jan 14, 2021.
• "International Space Law and Arms Control," Arms Control in an Era of Strategic Competition Workshop 4: Structural Models and Approaches: Scope, Participation and Structure in Competitive Arms Control, CSIS, Dec 18, 2020.
• "Regulation of Small Satellites," UNOOSA Space Law for New Space Actors Project, Dec 7, 2020.
• "Overview of Continuing Supervision of Non-Governmental Entities," UNOOSA Space Law for New Actors Project, Oct 15, 2020.
• "Legal Aspects of Planetary Protection," Presentation to the National Academies of Science, Committee to Review the Report of the Planetary Protection Independent Review Board, Nov 20, 2019.
• "Deficiencies and Pressing Issues in the Existing Legal Regime of Outer Space: the incompleteness of the legal order for space," Istanbul, Turkey, UN/Turkey/APSCO Conference on Space Law and Policy, Sep 24, 2019.
• "Emerging Space Players," Core Lecture, ISU Space Studies Program (SSP), Jul 15, 2019.
• "Stability and Sustainability: Overlapping Uses and Interests in the Space Domain(s)," SES Legal Workshop: Space Law in a Networked World at the University of Luxembourg, Jun 20, 2019.
• "Private Actors in Space (1)," 2019 Geopolitics and Global Futures Symposium at Geneva Centre for Security Policy in Geneva, Switzerland, Jun 13, 2019.
• "Conflict in Space: Preventable or Unavoidable?," Panel at McGill University in Quebec, Canada, May 15, 2019.
• "The United States in Space - Policy Objectives and Development," European Centre for Space Law 2018 Summer Course, Helsinki, Finland, Aug 28, 2018.
• "International Efforts to Prevent an Arms Race in Outer Space, including the Relevance and Sufficiency of Applicable Norms and Principles," International Workshop for the Prevention of an Arms Race in Outer Space, Beijing, China, Jul 4, 2018.
• "Space Sustainability Presentation," Dawn of Private Space Science, June 2018
• "The Secure World Foundation Handbook for New Actors in Space: best practices, capacity transfer, and integrating new actors into the governance domain of space," UNISPACE+50 - High Level Forum, Nov 8, 2017.
• "The United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) – History, Structure, Agenda, and Current Work (3)," Georgetown University Law Center, Space Law Seminar, Washington, D.C., Apr. 12, 2017.
• "Private Actors in Space," Geneva Centre for Security Policy, The Future of Outer Space Security, Mar. 23, 2017.
• "The United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) – History, Structure, Agenda, and Current Work (2)," International Institute of Air and Space Law, Leiden University, Mar. 14, 2017.
• "Context and History of the Outer Space Treaty," Georgetown University Law Center, 50th Anniversary Celebration of the Outer Space Treaty, Jan. 27, 2017.
• "Remarks on Establishing International Norms and Rules for Space Activities," Eleventh Annual Eilene M. Galloway Symposium on Critical Issues in Space Law, Dec 7, 2016.
• "Human trafficking, immigration and satellites," International Bar Association Space Law Committee, Human Rights Committee, and Immigration Committee, Sep 20, 2016.
• "New Actors in Space," 10th United Nations Workshop on Space Law-Contribution of Space Law and Space Security in the 21st Century, Vienna, Austria, Sep. 2016.
• "The United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) – History, Structure, Agenda, and Current Work (1)," Georgetown University Law Center, Space Law Seminar, Washington, D.C., Apr. 13, 2016.
• "Space For Peace Public Outreach Event," Israel Arts and Sciences Academy, Jerusalem, Israel, Oct 11, 2015.
• "The United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) – History, Structure, Agenda, and Current Work," Georgetown University Law Center, Space Law Seminar, Washington, D.C., Apr. 8, 2015.

Interviews / Media

• "China outlines position on use of space resources," SpaceNews, Mar 6, 2024.
• "Amazon is launching its first internet satellites to rival Starlink," Oct 5, 2023.
• "Why the first-ever space junk fine is such a big deal," Oct 5, 2023.
• "US astronaut returns from International Space Station after setting record," Sep 27, 2023.
• "The Reason We’re All Still Here," Global Space Law Center Symposium 2023, Cleveland State University Law, Sep 20, 2023.
• "Experts come together at ASU Space Futures event to discuss prospects, challenges of humans in space," Aug 25, 2023.
• "Cold War (to 1989), Public Space Station (permanent presence), Private Space launch (2001+), Comms Sat revolution, Space Manufacturing, Private Space Station, Moon Habitats (planning and operational phases), Mars Habitat (planning and operational phases)," Aug 25, 2023.
• "What’s next for the moon," Jul 24, 2023.
• "Space tourism companies might learn a lesson from the Titan sub disaster. But are they ready to listen?," Space.com, Jun 26, 2023.
• "Space Business: Lost in Orbit," Quartz, Jun 22, 2023.
• "Lunar laws could protect the moon from humanity," Apr 10, 2023.
• "5 Years Ago, SpaceX Launched Its Silliest Payload Yet — And It's Still in Orbit," Inverse, Feb 13, 2023.
• "Huge Satellite could Outshine all Stars and Planets in the Night Sky," Sep 9, 2022.
• "New legal ‘manual’ on peacetime military space activities could aid norms drive," Sep 8, 2022.
• "Battlefield Moon: What Space Exploration Means For Developers," Jun 25, 2022.
• "Russia wants to restart Germany's black-hole searching space telescope," Space.com, Jun 8, 2022.
• "The bizarre drama behind a pinch of moon dust that just sold for $500,000," Apr 13, 2022.
• "Civilian Satellites Could Face Legal Test In Russia-Ukraine War," Law 360, Apr 5, 2022.
• "US rejects charge that Starlink satellites endangered China’s space station," Breaking Defense, Feb 3, 2022.
• "US rejects charge that Starlink satellites endangered China’s space station (1)," Feb 3, 2022.
• "55-Years-Ago, The World Wrote the Prime Directives for Outer Space," Inverse, Jan 27, 2022.
• "Welcome to the space jam: Canadian startup Kepler stirs debate with huge planned fleet of internet satellites," The Globe and Mail, Dec 10, 2021.
• "Can SpaceX's Starlink sue Russia for anti-satellite missile test space debris fallout?," Space.com, Nov 29, 2021.
• "This Could Be Why Russia Blew Up Its Own Satellite," Inverse, Nov 27, 2021.
• "Orbital Flight to Be Next Chapter in Billionaire Space Race," Jul 20, 2021.
• "Human commercial space flights: many challenges and hurdles ahead, says US based expert," Financial Express, Jul 10, 2021.
• "This Is What Legally Happens If An Uncontrolled Rocket Damages Something," Planetary.org, May 5, 2021.
• "Moon Dialogs Bring Together Stakeholders in Near-Future Lunar Activity," Spaceflight Insider, Jan 12, 2021.
• "What is the Woomera Manual and how might it help stop a war in space?," ABC Radio National, Nov 12, 2020.
• "Starship Troopers? TRANSCOM-SpaceX Accord Raises Policy Eyebrows," Breaking Defense, Oct 7, 2020.
• "Who owns the Moon? No one! But we can use the resources, says Christopher Johnson, Space Law Advisor, Secure World Foundation," Financial Express, Sep 24, 2020.
• "Space Force-NASA Accord Highlights Cooperation Beyond Earth Orbit," Breaking Defense, Sep 22, 2020.
• "The Need for Engagement and Outcomes In Space Law - Cold Star Project S02E61," Cold Star Project Podcast, Sep 10, 2020.
• "Space Cafè WebTalk: 33 Minutes with Chris Johnson," SpaceWatch.Global, Aug 20, 2020.
• "Experts want to clarify how the laws of war on Earth apply beyond it," Economist, Aug 12, 2020.
• "NASA announces international Artemis Accords to standardize how to explore the Moon," The Verge, May 15, 2020.
• "Hard law or soft law? The debate about the future of space law," The Space Review, Apr 13, 2020.
• "WH Woos Potential Allies, Including China, For Space Mining," Breaking Defense, Apr 6, 2020.
• "New Executive Order Calls for International Agreements for Space Resource Rights but No New Treaty," SpacePolicyOnline, Apr 6, 2020.
• "White House Looks for International Support for Space Resources," SpaceNews, Apr 6, 2020.
• "Eyes in the Sky," Cosmos Magazine, March 2020
• "Legal action could be used to stop Starlink affecting telescope images," New Scientist, Feb 3, 2020.
• "“You’ll see the sky crawling”: Astronomers fear that satellites will crowd out stars," Vox, Jan 7, 2020.
• "Is India becoming a major source of space debris?," BBC News, Dec 23, 2019.
• "Stellar view? Space hotels race to offer tourists a room in the sky," Reuters, Dec 1, 2019.
• "The Risky Rush for Mega Constellations," Scientific American, Oct 31, 2019.
• "Beyond Anthropocentrism: Sustainable uses of Space," Space Junk Podcast, Oct 13, 2019.
• "Hundreds of satellites are watching from the skies. Should you be concerned?," The Telegraph, Sep 10, 2019.
• "Planetary Protection Laws: Tardigrades on the Moon," Space Junk Podcast, Sep 5, 2019.
• "Why Stowaway Creatures on the Moon Confound International Space Law," The Verge, Aug 16, 2019.
• "Mining the Moon," The Monthly, Jul 8, 2019.
• "Episode 8 – Chris Johnson," AstroEsq, Apr 16, 2019.
• "Trump's Space Force could be one giant leap into a tricky situation," Popular Science, Jun 19, 2018.
• "Woman says Neil Armstrong gave her moon dust. She's suing NASA to keep it.," Laura Cicco claims the moonwalker gave her the memento when she was a child., NBCnews.com, Jun 14, 2018.
• "Pirate Radio in Space Silicon Valley: startups meet space-law reality.," Slate, Apr 9, 2018.
• "The Outer Space Treaty: 50 Years Later," By Dario Schor, IEEE Canadian Review, Jan 22, 2018.
• "Outer Space Laws and Legislation: Regulating the Province of all Mankind," By Catherine Doldirina, Engineering & Technology Magazine, Jan 22, 2018.
• "50 Years of Space Law, Time to Rewrite the Rules?," By Sarah Kellog, The Washington Lawyer, Dec 1, 2017.
• "Can Japan Clean up Outer Space?," The Diplomat, Nov 21, 2017.
• "Space exploration will open up in 2018," The World in 2018, The Economist, Nov 1, 2017.
• "The Outer Space Treaty Turns 50. Can It Survive A New Space Race?," By Jason Krause, ABA Journal, Apr. 1, 2017.
• "Do We Need to Establish a Police Force in Space?," By Lauren Tousignant, New York Post, Feb. 10, 2017.
• "How an International Treaty Signed 50 Years Ago Became the Backbone for Space Law," By Loren Grush, The Verge, Jan 27, 2017.
• "To Boldly Go Where No Treaty Had Gone Before," By Catherine Meyers, Inside Science, Jan 27, 2017.
• "Legal Uncertainty May Keep Space Exploration Grounded," By Daniel Wilson, Law 360, Sep 7, 2016.
• "Commercial Exploitation of Space," Guest, A Public Affair WORT 89.9FM, Dec 18, 2015.
• "New US Space Mining Law to Spark Interplanetary Gold Rush," By Luc Olinga, Phys.org, Dec 8, 2015.
• "The US Launches a Gold Rush in Outer Space," By Luc Olinga, La Press, Dec 6, 2015.
• "Who Makes the Rules for Outer Space?," By Maggie Koerth-Baker, PBS NovaNext, Nov 30, 2015.
• "Space Law 2.0," By Kirsten Jusewicz-Haidle, Life of the Law, Nov 24, 2015.

SWF Preprints

• "SWF PREPRINT Security, Policy, and Legal Challenges of Planetary Defense," Sep 30, 2023.