Future Space Security


Growing U.S. and global dependence on space assets for a wide variety of scientific, economic, and military purposes has raised concerns about what might happen if such assets were to be threatened by hostile countries. Today, only the United States and Russia have tested space weapons of any sort, but a handful of other countries (including India and China) are believed to be conducting at least initial research into lasers and kinetic kill systems intended for space attack. With Russia's old anti-satellite system believed to be no longer operational and with the tentative nature of other foreign programs, the United States sits in a leadership position in this debate. At the Conference on Disarmament (CD), however, there is a stalemate in talks due to China's freezing of negotiations on all forms of arms control (including the Fissile Material Cut-Off Treaty) until the United States agrees to negotiations on a treaty to prevent the weaponization of space. Both sides have refused to budge, resulting in a stoppage of business at the CD for the past two years.

Thus far, the Bush administration has enunciated a largely military-driven response to space vulnerabilities, suggesting the inevitability of space-based weapons—both for missile defense and to protect U.S. satellites and other spacecraft. The administration has argued that treaties would only constrain law-abiding countries and that there would be no way to stop hostile states from violating these agreements. By contrast, many foreign governments and administration critics have made the case that diplomatic measures may be much more effective than military means in protecting space, particularly in the increasingly crowded realm of low-Earth orbit (60 to 300 miles above the Earth). They argue that it would be best to establish binding treaties before threats to space assets emerge. A variety of issues are involved, including complex questions regarding the nature of space debris that weapons tests will generate, as well as uncertainties regarding commercial and political implications.

Space is a realm currently used for scientific, commercial, and military purposes. Satellites make weather reporting possible, allow people to call and transmit data overseas instantaneously, and facilitate the flights of precision-guided munitions (of the type used in the Gulf War and in Afghanistan) to their targets with great accuracy. What worries the Bush administration and many military planners is what might happen if these assets themselves were to be threatened in some future war or by a rogue state or terrorist attempting to cripple the U.S. economy. While such threats today merely exist in theory, it would not be beyond the capability of almost two dozen countries to develop and deploy crude anti-satellite weapons that could be launched into space to attack U.S. assets. For example, a country might launch a small satellite packed with pebbles or nails and direct it into a high-speed collision with a critical U.S. satellite or spacecraft. Orbital objects travel at speeds of approximately 18,000 mph, meaning that such collisions would certainly be fatal. Critics note that such weapons do not yet exist, that their development and testing would be transparent and therefore possibly preventable, and that the United States has other military means to prevent their use. But there are other issues as well.If the United States hopes to develop an effective national missile defense, it will need to rely on a variety of space-based sensors and tracking radars and possibly constellations of space-based lasers and kinetic kill satellite weapons. In wartime, these systems could create inviting targets for U.S. adversaries. For these reasons, the Bush administration wants to investigate its options and develop weapons capable of meeting these threats before they arise. Few analysts, however, have worked out the possible long-term implications of such deployments on the physical environment of space (particularly low-Earth orbit) or their political ramifications. Existing treaties governing space (see chart below) ban the stationing of weapons of mass destruction in orbit, ban nuclear testing in space, and forbid states from engaging in activities might threaten other parties without providing prior warning. They also require compensation for damage caused to spacecraft and call for all activities to be carried out for "peaceful purposes." Nonetheless, there are gaps in these agreements and room for possible differences of interpretation of various clauses that may open the door to space weapons. In addition, there is the possibility that certain states may simply violate the treaties altogether, if push comes to shove.

Possible Types of Weapons

Space weapons under consideration today consist of several basic types. First, ground-, sea-, and air-based missile defense interceptors all use low-Earth orbital space as a location for the interception of ballistic missiles passing through space, usually at altitudes of a few hundred miles or less. The bulk of weapons in the current missile defense test program of the United States consist of this type of non-space-based interceptors. Second, space-based weapons are being considered for future development, testing, and deployment against ballistic missiles, but probably not until sometime after 2010 (due to technical obstacles). These systems include kinetic kill interceptors that would destroy missiles by collision alone and space-based lasers that would send high-powered beams at rising missiles in order to disable or destroy them. A third type of space weapon is anti-satellite systems, of which various designs are possible. Some might be direct-ascent missiles that would be launched into space and either collide directly with or detonate conventional explosives near their targets to destroy them. Others might be space-based systems that would be moved into companion orbits and exploded near target spacecraft. Although treaties currently prevent the testing of nuclear weapons in space, nuclear-tipped anti-satellite and anti-missile systems could be developed if the existing treaty regime were to collapse under political pressures caused by uncontrolled space weaponization. Despite U.S. leadership in space, the Bush administration has tasked the Defense Science Board with investigating possible low-yield nuclear weapons for missile defense purposes if existing kinetic kill systems fail to achieve their goals.Debris and Radiation as Hazards in Space

There are currently some 500 operating satellites of various types orbiting the Earth. Most communications (including broadcast) satellites are in remote, geo-stationary orbits at 22,300 miles above the Earth, where they remain virtually motionless above fixed locations. Military satellites used for early warning of missile launches are also located at this altitude. Closer to Earth, certain communications and reconnaissance satellites travel through highly elliptical orbits coming close to Earth at their lowest points (a few hundred miles) and reaching apogees of a few thousand miles. Even lower, more circular orbits are used by satellites used for remote sensing of the Earth's topography or plant life, as well as those serving localized cellular or pager networks. Constellations of these satellites are needed in order to keep at least one spacecraft above particular locations on a constant basis. Certain military satellites used for targeting, tracking, and close-in reconnaissance are also often in low-Earth circular orbits. The International Space Station is in orbit at an average altitude of 240 miles.Also in orbit around the Earth are some 9,000 trackable pieces of space debris. These include bolts from stage separations, old satellites, stray pieces of metal from past spacecraft, and other material. U.S. Space Command in Colorado tracks this debris and provides information to launching states to help them prevent collisions. Even smaller particles of so-called "micro-debris" also orbit the Earth and cause ongoing damage to spacecraft. The U.S. Space Shuttle has suffered costly damage from such collisions, which have required more than 25 window replacements at several million dollars each. One such incident involved a deep gouge caused by an orbiting paint fleck. Collisions with larger pieces of debris can be fatal, and there has been at least one incident in which a satellite was destroyed.

Electro-magnetic pulse (EMP) radiation from nuclear testing conducted by the United States and Soviet Union during the 1958-62 period disabled several early communications and reconnaissance satellites before the two sides discontinued such tests in 1963. Today, some military satellites are "hardened" to protect them against EMP and against collisions with micro-debris, but this adds cost and weight to these spacecraft. However, there is no way of protecting satellites against collisions with larger pieces of debris or nearby explosions of nuclear weapons.

Commercial Interests

Commercial uses of space continue to expand. These spacecraft inhabit a variety of locations and orbits, some of which, particularly in the geo-stationary belt, are becoming increasingly crowded. Debris is particularly dangerous in orbits below 600 miles, where more space activity has taken place historically. Nevertheless, U.S. commercial space providers have not yet raised significant opposition to plans for U.S. space weapons. One reason is the fact that most satellite providers also build spacecraft for the U.S. military. Another is the belief of these companies that the U.S. government, recognizing the importance of space commerce to the U.S. economy and of debris limitations for commercial and passive military users, despite the rhetoric heard today regarding the need for various types of space weapons, will not adopt weapons that will cause significant damage to space. What is not clear, however, is what response limited U.S. testing and deployment of space weapons might elicit from other countries. A country with only limited space dependence might, in a crisis, decide to launch large amounts of debris into low-Earth orbit in order to cause asymmetric damage to U.S. military and economic interests.

Already, the U.S. Federal Communications Commission is circulating for comment a draft set of rules for debris mitigation by U.S. commercial users. These rules require that satellite companies boost satellites beyond their service lives into high "parking" orbits (where they will sit for thousands of years) or to de-orbit them back to Earth, where they will burn up in the Earth's atmosphere. There are also discussions going on the international level within the UN Committee on the Peaceful Uses of Outer Space on the possible creation of a multilateral convention on debris mitigation. Despite these negotiations, there currently are no binding international agreements requiring states to limit space debris.


The outcome of the space weapons debate is still unclear. Most states are on record opposing the notion of an arms race in outer space. However, U.S. dependence on space and desire to protect the U.S. population from possible missile attack has led the Bush administration to consider various types of space weapons. Few decisions have been made, although test programs for missile defense purposes are continuing. Moreover, a test of the Army's Kinetic Energy Anti-Satellite (KE ASAT) system is being considered within the next two years, raising some pressures for action at the international level. The Bush administration has opposed international efforts (led by China) to negotiate a formal international treaty banning space weapons. Yet, recent statements by U.S. officials about the right of sovereign states to acquire information from space may indicate U.S. support for the concept of non-interference with satellites.

Looking ahead, there may be room for consideration (short of formal treaties) of new unilateral, bilateral, and multilateral pledges and resolutions to expand existing protections and make space less vulnerable to irresponsible weapons testing, deployment, and debris-generation, even under the Bush administration. However, such efforts will take political leadership and more developed forms of cooperation among military, commercial, and other users of space than has been present to date. There are signs of growing international dialogue on certain issues (such as debris) that might lead states into broader discussions on space security. Thus, there may still be room for new compromises between the Bush administration and its critics.


Articles and Reports

  • Maj. Howard D. Belote, "The Weaponization of Space: It Doesn't Happen in a Vacuum," Aerospace Power Journal, Spring 2000.
  • Lt. Col. Bruce M. DeBlois, "Space Sanctuary: A Viable National Strategy," Aerospace Power Journal, Winter 1998.
  • Theresa Hitchens, "Rushing to Weaponize the Final Frontier," Arms Control Today, September 2001, www.armscontrol.org.
  • Jack Hitt, "Battlefield: Space," The New York Times Magazine, August 5, 2001.
  • Michael Krepon, "Lost in Space: The Misguided Drive Toward Antisatellite Weapons," Foreign Affairs, May/June 2001.
  • Lambakis, Steven, "Space Weapons: Refuting the Critics," Policy Review, No. 105 (February/March 2001).
  • James Clay Moltz, "Breaking the Deadlock on Space Arms Control," Arms Control Today, April 2002.
  • James Clay Moltz, "Space Arms Control and the International Missile Defense Debate," in Missile Proliferation and Defences: Problems and Prospects, CNS Occasional Paper No. 7 (joint publication with the University of Southampton's Mountbatten Centre), July 2001.
  • Mike Moore, "Unintended Consequences," The Bulletin of the Atomic Scientists 56, January/February 2000.
  • Michael O'Hanlon, "Star Wars Strikes Back," Foreign Affairs, November/December 1999.
  • Charles V. Pena, and Edward L. Hudgins, "Should the United States ‘Weaponize' Space? Military and Commercial Implications," Policy Analysis (Cato Institute), No. 427, March 18, 2002, www.cato.org.
  • Steven Lambakis, "Space Weapons: Refuting the Criticis," Policy Review, No. 105 (February/March 2001).


  • Donald R. Baucom, The Origins of SDI, 1944-1983 (Lawrence: University Press of Kansas, 1992).
  • J. Marshall Beier, and Steven Mataija, eds., Arms Control and the Rule of Law: A Framework for Peace and Security in Outer Space (Toronto: Centre for International and Security Studies, York University, 1998).
  • Frances Fitzgerald, Way Out There in the Blue: Reagan, Star Wars and the End of the Cold War (New York: Simon & Schuster, 2000).
  • George and Meredith Friedman, The Future of War: Power, Technology, and American World Dominance in the Twenty-First Century (New York: St. Martin's Press, 1996).
  • Norman Friedman, Seapower and Space: From the Dawn of the Missile Age to Net-Centric Warfare (Annapolis: Naval Institute Press, 2000).
  • Steven Lambakis, On the Edge of the Earth: The Future of American Space Power (Lexington: University Press of Kentucky, 2001).


  • Nukes in Space (Thousand Oaks: Goldhil Video, 1999).

Government Documents

  • Committee on Armed Services of the U.S. House of Representatives, "Report of the Commission to Assess United States National Security Space Management and Organization, Executive Summary, Pursuant to Public Law 106-65," January 11, 2001, (also known as the "Rumsfeld II" report).
  • U.S. Air Force, "America's Air Force: Vision 2020," updated June 4, 2002.


  • www.SpaceDaily.com
  • Orbital Debris Quarterly, Johnson Space Center, NASA, http://orbitaldebris.jsc.nasa.gov.
  • Aerospace Power Journal, U.S. Air Force, www.airpower.au.af.mil.
July 1, 2002

In this 2002 article, James Moltz explores the future of space security, highlighting increased commercial interests and the evolution of space weapons.

James Clay Moltz

Deputy Director, Center for Nonproliferation Studies