Text Only | Disarmament Diplomacy | Disarmament Documentation | ACRONYM Reports
back to the acronym home page
WMD Possessors
About Acronym
Disarmament Diplomacy, Cover design by Paul Aston

Disarmament Diplomacy

Issue No. 66, September 2002

Opinion & Analysis

Drawing the Line: the Path to Controlling Weapons in Space

By Philip E. Coyle and John B. Rhinelander


What positive and constructive role can the United States play in controlling the weaponisation of space? Will leadership come from the United States or will it come from the international community more broadly? Is the weaponisation of space inevitable, and will it follow inexorably from the historical weaponisation of land, sea and air? These and related questions are becoming prominent as the United States and other states make increasing investments in space both for military and commercial purposes. This paper provides some answers to these questions.

Bruce M. DeBlois and Richard L. Garwin recently articulated the position of space-weaponisation enthusiasts that weaponisation of space is inevitable. In the opening Proposition of their 'Six Incentives for Space Weaponisation' White Paper, written for the Council On Foreign Relations (CFR) Study Group on United States Space Posture for the 21st Century, they wrote: "Where goes man goes the clash of opposing wills and the instruments to effect that clash: weapons. This progression was true of territorial frontiers throughout history, true of the high seas in the Middle Ages, and true of the air realm in the 20th century. The same is destined to be true in outer space." While this may not be the view of the authors, the paper certainly makes the case that arms control in space will not be easy.

But is human nature determinedly at cross-purposes with controlling weapons in space? And is space different - and is the value of space for communication, commerce or travel different - in ways that might actually limit the extent to which space becomes weaponised?

Space Is Different!

First, unlike the land and the continents, no country "owns" space. Space is not a sovereign territory. It could be likened to Antarctica where the major powers have agreed to share responsibility for the region's safe-keeping, but not to fight over it or weaponise it. The 1959 Antarctic Treaty pledges the continent to peaceful use, provides for free exchange of scientific information, and bans new territorial claims. Except for scientific exploration, the untapped oil and gas reserves and minerals of Antarctica also are tightly controlled by the treaty. But those hidden natural resources, no matter how extensive they might turn out to be, are not Antarctica's greatest value; undoubtedly, its supreme worth is as a sensitive beacon of the world's future climate and of the planet's biological history and future.

Since it is not subject to sovereignty claims of any state, outer space is different from land and even airspace. Remarkably, however, one crucial aspect of this distinction - especially that between airspace and outer space - remains uncodified. The altitude at which space begins has never been defined internationally. Space is defined by the US Department of Defense as "beginning" at an altitude of 100 miles, but in the United States astronaut wings are awarded for flights that reach 50 miles or higher.1 Eventually a more rigorous definition will be needed.

Dependence on Space

The commercial use of space is already an inseparable part of our daily lives. Our maps and clocks derive from the measurements from imaging satellites and the Global Positioning System (GPS) satellite navigation network. Our telephones, televisions, computers, and bank accounts depend on satellite communications. And our knowledge of the weather comes from overhead satellites that track every cloud. According to an ongoing study by the Union of Concerned Scientists (UCS), the United States has about 200 commercial and civil satellites in operation today, followed by the European Space Agency (about 50), Russia (about 30), and Japan (about 25).

The rate of growth in space assets was dominated for decades by military considerations. It was 44 years ago, on January 31, 1958, that America conducted its first successful satellite launch into space, four months after Sputnik. However, 40 years would pass before there were "not only more commercial satellites in orbit than military satellites, but also more commercial space launches than military".2 Since then the number of commercial launches has exceeded military launches, and these days the US military depends on commercial satellites for many functions. Satellites that are counted as "commercial" are in heavy use by the US military, and it is sometimes difficult to say whether a satellite is more "commercial" than "military". GPS is an example of a system originally launched by the US military but now in heavy commercial use. Conversely, satellites originally launched for commercial purposes can be dominated by US military use.

These developments create a situation where communication and commerce worldwide - not to mention military operations - are becoming dependent upon space to a degree never imagined when the Outer Space Treaty (OST) was being negotiated 35 years ago. In the United States, and in much of the rest of the world, space communications have taken on a personal, human intimacy that is different in kind and degree from business communications 40 years ago.

It is not likely that the United States will be able to separate its military interests in space from its commercial space interests, and in that sense also the US military will not be able to "own" space, nor own all the commercial satellites with military value. To put it differently, the United States certainly has an interest in the military use of space, and from a US point of view, space already is "militarised" through the day-to-day use of satellites, whether military or not. However, so far the United States has put relatively little of its defence budget towards true space strike or attack weapons. Clearly, the US needs to think carefully about the extent to which it wants to see space weaponised, since it has so much at stake, both commercially and militarily, and so much to lose in any outer space arms race.

A particularly important region of space is Low-Earth Orbit (LEO), ranging from roughly 180 miles to 1,200 miles up. This is the most crowded region of Earth-orbiting satellites for both military and commercial/civil satellites, and home to everything from the Hubble Space Telescope, the International Space Station, weather satellites, and many military and mobile-phone satellites. LEO would also be home to 24 or so of the US Space-Based Infrared System-Low Earth Orbit (SBIRS-Low) satellites, which with SBIRS-High would make up Washington's proposed 30-satellite SBIRS system. Finally, in the longer-term LEO could become home to perhaps as many as 1,500 US Brilliant Pebbles anti-missile satellites, should they be developed and deployed. If war in space is inevitable, it would likely start in LEO, if for no other reason than that much of the potential conflict in space will be clustered there.

Information vs. Shooters/Situational Awareness vs. Strike Attack

With respect to comprehensive agreements relating to outer space, it is necessary to consider the options. While some people might favor the notion that space, like Antarctica, should be a sanctuary with no activities in, through or from outer space by the military, or of utility to the military, of any state, that time has already passed. Space Sanctuary ended years ago, even before the OST was negotiated in 1967. Broadly defined, Space Sanctuary would ban reconnaissance, surveillance and communication assets operated by or used by the military, including those with dual use. Any effort to roll the clock back and prohibit these efforts is a non-starter. Similarly, it is too late to draw the line at space utilisation for non-strike military purposes - including reconnaissance, surveillance and communication satellites where the recipients of the information from the satellites include military agencies. Space is already "militarised" by both military and commercial satellites.

The only practical place to draw the line today is space weaponisation, that is military strike vehicles - "shooters" - whether located in space or otherwise, that are tested and deployed for warfare in space or elsewhere. Space weaponisation with strike vehicles, as opposed to space utilisation for non-strike military purposes, should be the focus of the discussions of permitted and prohibited activities.

Space weaponisation, if defined as dealing with strike vehicles but not sensors, is the classification that presumably would ban activities of greatest concern and where agreement might be possible at some point in time. To be fruitful, discussions should be focused on particular functions (e.g., a LEO-based laser to intercept ground-based offensive missiles that transit space), rather than general bans. While the latter may appear an attractive approach, it is unlikely be productive due to the complexity of the issue.

Military Assets in Space

Military assets in space can be thought of in three broad categories: communications satellites, sensor satellites, and shooters or strike weapons. At present, the US has about 110 operational military assets in space, Russia about 40, and the rest of the world (including Australia, China, Europe, India, Israel, Japan, South Korea, Taiwan and Turkey) about 20. None of these assets are strike weapons. Their roles include reconnaissance, surveillance and communications.3 Satellites that connect to ground stations, or to land, sea or aircraft based platforms, to act as relays or transmit radio or television signals can easily have both military and commercial applications. Satellites that only track the weather, or provide pictures over land and sea, also fall into the sensor category. Such satellites can also easily have both military and commercial value. Thus satellites in the communications and sensor categories are difficult to deal with from an arms control point of view. While many communications satellites or space sensor platforms have been and will be launched exclusively for military use, their generic nature makes them problematic subjects for arms treaties, just as radios or cameras are not regulated by such treaties. Communications and sensor satellites can be thought of as "passive" even though they would be an active part of battle.

Shooters are active military satellites with the direct capability to launch projectiles or directed energy beams at targets for strike purposes, whether offensive or defensive. An example is the Space-Based Laser being developed as part of President George W. Bush's layered missile defence plan. Also, the US Army has experimented with high-power ground-based lasers that could damage a satellite in orbit. But more realistically, for both defence and for offensive space weapons capability, shooters will primarily mean anti-satellite weapons (ASATs). These might be satellites carrying "kinetic kill vehicles," rockets, space mines, or cannons. The Soviet Union and the United States each tested ground-based and air-based ASATs into the 1980s. The US Air Force has experimented with ASAT concepts where projectiles are launched either from high-flying fighter aircraft or from satellites in space. Space-based kinetic kill vehicles might shoot smaller interceptors from platforms in space. Eventually, the administration intends to do a space "hit-to kill" experiment to demonstrate proof-of-concept of a kinetic kill configuration.

Active, offensive anti-satellite platforms with "shooting" capabilities clearly must be the next major focus in arms control efforts. The number of military assets in space for non-strike purposes is still relatively small, the United States has a commanding lead in space, and strike weapons are not yet a factor, but soon could be if not controlled. Not since the development of the atomic bomb has the United States had an equivalent opportunity and incentive to show leadership for restraint in the development of a new class of weapons, namely weapons in space. Here, the restraint is in using space for offense, for attack, not for knowledge. The concept of employing space assets for knowledge and for situational awareness is already well established and accepted.

Space Debris

The problem of space debris is a factor in the weaponisation of space, and in the ability of arms control agreements to deal with weapons in space for both defensive and offensive purposes. Reportedly, the US Space Command currently tracks about 9,000 man-made objects larger than four inches across. Most of these are small objects, the result of shroud or stage separation, missile break-up, or other phenomena. The exact number of man-made objects is impossible to catalogue, but there are reportedly hundreds of thousands, or even millions, of smaller man-made objects ranging from golf ball-sized objects to flecks of paint. The increase in space debris has become such a concern to the US military that it voluntarily constrains its activities likely to further aggravate the problem. Obviously, weapons fired at objects in space would very quickly and dramatically add to the burden from space debris.

Just as space debris can "passively" destroy operational satellites, so it can also be launched into space and used as a satellite killer. One simple and relatively inexpensive concept for destroying a constellation of US satellites would be for an adversary to launch rocket-loads full of gravel to "intercept" them in orbit. This threat alone would be justification for the US military to take a stronger role in arms control in space.

Missile Defence and the Weaponisation of Space

A complicating aspect of the debate about the weaponisation of space is the dedication of the current Bush II administration to deploy missile defence systems capable of intercepting or shooting down intercontinental-range ballistic missiles (ICBMs). A land- or sea-based system capable of such intercepts would almost automatically be capable of also intercepting satellites in LEO. In addition, of course, a space-based laser or space-based kinetic kill vehicle system would already have such a capability. The Brilliant Pebbles concept, first articulated clearly in the Bush I administration, could also be used either for missile defence or as an attack system to destroy satellites in orbit. The argument could be made that, if deployed, Brilliant Pebbles, the Space-based Kinetic Kill system, or the Space-Based Laser, while intended as defences against enemy ICBMs, would increase the chances that someday there will be an arms race, and possibly eventual conflict, in space.

Shooting down a satellite in LEO is easier than shooting down an ICBM in mid-course that may be equipped with various decoys and countermeasures. In the case of an incoming ICBM, the defender may not know the exact trajectory or the nature of countermeasures used. In the case of satellites, such targets are essentially sitting ducks whose orbit paths are known precisely and well in advance. Essentially, therefore, missile defence systems are "shooters" in that they will have an inherent capability to attack space assets in orbit as well as missiles in flight.

Some Next Steps for Arms Control

In a paper delivered to a meeting of the Pugwash Conferences for Science and World Affairs in Moscow in July this year4, John Rhinelander recommended a three-level focus on additional restraints on space activities. The proposed steps are:

(1) modest - multilateral agreement on non-interference with "peaceful" assets orbiting in space, enlarging upon the 30-year old examples from Strategic Arms Limitation Talks (SALT) and the Strategic Arms Reduction Treaties (START I and II) that prohibited interference and concealment from National Technical Means (NTM), i.e. spy and early warning satellites, perhaps in the form of a United Nations General Assembly resolution;

(2) intermediate - one and perhaps two "permissible interpretations" of the OST that would ban orbiting killers weapons, however armed, and perhaps require mitigation of debris in space; and,

(3) comprehensive, and furthest off - a series of amendments to the OST or a new freestanding treaty that would include forbidding attack vehicles in space and establish the technical means of verification.

Caucus of State Parties to the OST

A caucus of states parties to the OST this fall in New York during the United Nations General Assembly meeting would enable a first discussion of these three elements. While, following consultations with other states, China and Russia are not inflexibly committed to restricting space weaponisation negotiations to the Conference on Disarmament (CD) at Geneva, they continue to strongly value the benefits of operating under the aegis of the United Nations. A caucus at the UN in New York, which need not be subject to the CD's frequently-abused consensus rule, would accommodate this preference and probably represent the least costly alternative to Geneva discussions. The current US position seems to be that it is willing to discuss, but not open negotiations on, the issue; logically, therefore, the United States could be expected to participate in such a caucus.

Initially, the caucus should agree to sponsor a UNGA resolution this fall that builds upon the 30-party Conventional Forces in Europe (CFE) treaty. Article XV of the CFE prohibits interference with national and international technical means of verification. A General Assembly resolution should universalise the obligation from the current 30 to all states, and should expand its scope from photographic and other technical means of verification to all current types of orbiting satellites. This would include communication and other types of satellite of prime interest to most of the world.

Secondly, any review of the OST should include targeted amendments in addition to permissible interpretations of the current text. An amendment would require the support of a majority of states parties. Quite obviously, an amendment or permissible interpretation unanimously or overwhelmingly endorsed by the treaty's 96 members would be very significant, and could include an explicit prohibition on tests against targets in space.5 This would also open the way for discussion of the ASAT capabilities being demonstrated in current anti-ballistic missile (ABM) tests at relatively low altitudes in space, as well as those planned at higher altitudes later.

The ultimate goal of these discussions would be step 3, listed above - a multinational agreement banning the testing and deployment of any weapon strike system against orbiting satellites, whether ground-based, sea-based, air-based or space-based, including weapons that blind or disable but which do not entirely destroy a satellite. Such a ban could also cover the testing and deployment in space of attack vehicles (whether ASAT, anti-missile or ground/sea/air attack), but not any ballistic missile defence system other than those with space-based killers. This ban should not extend to various types of space-based sensors, including SBIRS-Low.6 The Pentagon is exploring the concept of small attack satellites to defend SBIRS, and such attack satellites would be forbidden under the recommended approach.

Forums on Verification Means

Verification will be critical to a comprehensive approach, including exchange of information, transparency, inspection, and shared observations about the technology and future directions of reconnaissance from space. The situation is aided by the fact that the observation of platforms in space from high-resolution telescopes on the ground or from space has become highly accurate. Nevertheless, verification will be extremely difficult for certain types of prohibited or constrained activities, such as space mines, which may be easily disguised as something else. While the United States and the Soviet Union readily accepted NTM as the baseline of their verification activities in SALT, augmented after the 1987 Intermediate Nuclear Forces (INF) Treaty by on-site inspections and other measures, a verification approach based on NTM would likely be unacceptable in a multilateral agreement unless access to some form of NTM data was available to all. The United States and Russia do not regularly share NTM data with one another, and when US-Soviet agreement on NTM was first reached in 1972 no comparable data was available to other states.7 Now, there are generally available commercial sources of data from space. However, on-site inspections and other forms of transparency will be necessary in certain instances. These will be difficult issues to handle.

Indeed, any comprehensive agreement, even if approached on a step-by-step basis, will be difficult.8 It would probably be wise to begin exploration of each substantive issue with associated verification measures. Track II discussions and non-governmental organisation conferences could have important roles after initial discussions get started among governments.

The Need for Leadership

The crucial point to emphasise is that outer space issues are becoming urgent, and a forum must be found to start a dialogue as early as possible. Groups of states should begin to wrestle with the issues, including one or more Western groups mindful of, but not speaking for, the United States. The New Agenda Coalition (Brazil, Egypt, Ireland, Mexico, New Zealand, South Africa and Sweden) might be one group, as might the NATO-5 (Belgium Germany, Italy, Netherlands and Norway).

The United States has and will continue to have more interests in space assets both civil and military than most countries, and it will retain a net benefit if no one (including the United States itself) has weapons in space. With the United States being more dependent on space for television, cell phones, and communications than any other country, most Americans - and most members of Congress - would support the ability of the United States to defend its communications and surveillance assets in space. Offensive space weapons, however, would rightly be regarded as another matter.

Under an arms control regime prohibiting space weaponisation, the United States would base its military "defence" of its space-based assets on hardening, redundancy, and readiness to launch new platforms if any systems were lost or attacked. Of course, if any state breached a space treaty, the United States, and any other state, could suspend or terminate its legal obligations if the breach were material. Also, the United States would plan sufficient lead-times to offset any adverse act through the deployment of replacement space assets. This approach is similar to that first used successfully with regard to SALT I.


The United States and other states are at the point where they will soon be adding scores of new military satellites to space for reconnaissance and communications purposes. If history is any guide, the military will press for strike weapons to defend those space assets, to control space, and ultimately to be able to wage war in space, if deemed necessary. The numbers of military satellites are still relatively small but the number of objects in space that must be dealt with is enormous. It is time to begin serious discussion in the international community for ways to control weapons in space.

Notes and References

1. US Space Command Spokesperson Air Force Major Perry Nouis, "Down-To-Earth Space Questions", SpaceDaily.com, April 9, 2001.

2. "NASA 1998: The Year in Space", Office of Space Flight, Dr. Jesco von Puttkamer.

3. The most recent discussion in open literature on military activities in space is an article by John Pike entitled "The Military Uses of Outer Space", featured in the Stockholm International Peace Research Institute's (SIPRI) 2002 Yearbook. Dr. Jonathan McDowell's Space Home Page at Harvard University - http://hea-www.harvard.edu/QEDT/jcm/space/space.html - is another excellent source.

4. "Strategic Stability and Arms Control After the ABM Treaty, John B. Rhinelander", July 8, 2002, pp. 4-8. See also the letter to the editor from George Bunn and John Rhinelander that first suggested interpreting the OST to ban all orbiting weapons, however armed, in Arms Control Today, June 2002.

5. In addition to the 96 states parties, 27 states have signed but not ratified the OST. For details and related documentation, see the United Nations Office for Outer Space Affairs (UNOOSA) in Vienna, http://www.oosa.vienna.org/treaty/ost/ost.html.

6. This, incidentally, was the position of Paul Nitze at the SALT I talks in 1971 before President Richard Nixon went further and agreed to seek to ban space-based sensors substituting for anti-ballistic missile radars in the ABM treaty.

7. The United States no longer opposes voluntarily sharing NTM data on an ad hoc basis. Its NTM data has been critical to the IAEA in its monitoring of North Korean nuclear activities. In addition, the CTBT, which the US initially promoted but has not yet ratified, anticipates receipt of national NTM data in the case of calls for special inspections.

8. James Clay Moltz puts forward a five-element proposal in his article "Breaking the Deadlock on Space Arms Control", in Arms Control Today (April 2002), pp. 3, 8. The proposal sets out four prohibitions and one permitted activity (testing of ground-, air- and sea-based missile defense interceptors).

Philip Coyle is a Senior Advisor to the Center for Defense Information (CDI), a defence consultant, and former US Assistant Secretary of Defense for Test and Evaluation. John Rhinelander is senior counsel, Shaw Pittman; Vice Chairman of the Lawyers Alliance for World Security and a member of the Board (and former Vice Chairman) of the Arms Control Association. This article is based on a longer paper prepared for the 52nd Pugwash Conference on Science and World Affairs in LaJolla, California, August 10-14, 2002.

Back to the Top of the Page

© 2002 The Acronym Institute.