Outer Space Treaty

Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies (Outer Space Treaty)

The Outer Space Treaty obligates Parties not to place any objects carrying nuclear weapons in orbit, on the Moon, or on other celestial bodies.

  • Ratified

See Status

Ratified (136)

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Opened for Signature

27 January 1967

Entered into Force

10 October 1967

Treaty Overview

  • Depositaries: Russia, United Kingdom, and United States


The Outer Space Treaty was adopted by the UN General Assembly (UNGA) in resolution 2222 (XXI) after being considered by the Legal Subcommittee in 1966. The Treaty added new provisions to the foundation provided by the Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space, which had been adopted by the General Assembly in 1963 in resolution 1962 (XVIII).

Treaty Obligations

he Treaty stipulates that exploration and use of outer space shall be carried out for the benefit and in the interest of all countries, and it shall be the province of mankind. Parties agree not to place in orbit around the Earth any objects carrying nuclear weapons or any other kinds of weapons of mass destruction; not to install such weapons on celestial bodies, or station them in outer space in any other manner; the Moon and other celestial bodies are to be used exclusively for peaceful purposes; establishment of military bases, installations and fortifications, the testing of any type of weapons, and the conduct of military maneuvers on celestial bodies shall be forbidden.

Verification and Compliance


States Parties agree to inform the UN Secretary-General as well as the public and the international scientific community, to the greatest extent feasible and practicable, of the nature, conduct, locations, and results of activities covered in this Treaty. The Treaty sets forth that all stations, installations, equipment, and space vehicles on the Moon and other celestial bodies shall be open to representatives of other States Parties on a reciprocal basis; such representatives shall give reasonable advanced notice of their projected visit, so that appropriate consultations may be held, and so that maximum precautions may be taken to assure safety and to avoid interference with normal operations of the facility to be visited.


When activities are carried on in outer space by an international organization, responsibility for compliance with this Treaty shall be borne both by the international organization and by the States Parties to the Treaty participating in such organization. No specific measures for compliance are included in this Treaty.




From 29 January to 9 February, the 55th Session of the Scientific and Technical Subcommittee met in Vienna.

From 9 to 20 April, the 57th Session of the Legal Subcommittee met in Vienna.

From 20 to 29 June, the 61st Session of the Committee on the Peaceful Uses of Outer Space took place in Vienna.


From 30 January to 10 February, the 54th Session of the Scientific and Technical Subcommittee met in Vienna.

From 27 March to 7 April, the 56th Session of the Legal Subcommittee met in Vienna.

On 22 May, Malta acceded to the treaty.

From 7 to 16 June, the 60th Session of the Committee on the Peaceful Uses of Outer Space took place in Vienna.


On 15-26 February, the 53rd Session of the Scientific and Technical Subcommittee met in Vienna. The Subcommittee released a final report outlining its priority areas as well as defining its mandate.

On 3 March, the 36th session of the United Nations Interagency Meeting on Outer Space Activities took place in New York. The group submitted a report on the implementation of transparency and confidence building measures in outer space activities.

On 4-15 April, the 55th session of the Legal Subcommittee of the Committee on the Peaceful Uses of Outer Space took place in Vienna. The subcommittee submitted a final report on the legal mechanisms pertaining to outer space.

On 8-17 June, the 59th session of the Committee on the Peaceful Uses of Outer Space took place in Vienna and was attended by 70 states. The committee reaffirmed its goal of maintaining outer space for peaceful purposes. The committee also agreed upon a First Set of Guidelines on the Long-term Stability of Outer Space Activities and identified seven priorities for UNISPACE+50.

On 28 June, the UN Office for Outer Space Affairs and the Sierra Nevada Corporation signed a Memorandum of Understanding to provide opportunities for UN member states to conduct experiments in outer space. From 5-8 September, the 10th UN Workshop on Space Law took place in Vienna, Austria. Recommendations were made on how to increase the safety, security, and sustainability of outer space activities, capacity building for developing nations in space law, and the intersection of cyber security and space law.

On 27 September, the UNOOSA and SNC announced details of the first ever UN space mission. The mission will give developing countries opportunities to develop and launch microgravity payloads into orbit. The space mission is set to launch in 2021.


On 2-13 February, the 52nd session of the Scientific and Technical Subcommittee of the Committee on the Peaceful Uses of Outer Space took place in Vienna. 61 States members attended the session. The subcommittee submitted a final report and the Working Group on the Use of Nuclear Power Sources in Outer Space also submitted a report.

On 13-24 April, the 54th session of the Legal Subcommittee of the Committee on the Peaceful Uses of Outer Space was held in Vienna. The subcommittee submitted a final report. Working Groups on Definition and Delimitation of Outer Space, Status and Application of Outer Space Treaties, as well as International Mechanisms for Cooperation submitted their reports respectively:

A/AC.105/C.2/2015/DEF/L.1, A/AC.105/C.2/2015/TRE/L.1, A/AC.105/C.2/2015/IMC/L.1.

On 10-19 June, the 58th session of the Committee on the Peaceful Uses of Outer Space took place in Vienna. 66 States Members attended the session. The committee submitted a report.



On 9 February, NASA accepted applications from companies that want to mine the moon for rare materials such as Helium-3 under a program called “Lunar Cargo Transportation and Landing by Soft Touchdown” (CATALYST). The Outer Space Treaty prohibits any country from claiming property on the moon, but lunar mining has sparked debate over lunar property rights.

From 24 March to 4 April, the fifty-third session of the Legal Subcommittee of the Committee on the Peaceful Uses of Outer Space was held in Vienna. The Subcommittee submitted a draft report to the General Assembly and the chair of the Working Group on the Status and Application of the Five United Nations Treaties on Outer Space also submitted a report.

On 31 March, the EU Council made public their fifth revised draft of a Code of Conduct for Outer Space Activities.

From 27-28 May, the third EU open-ended consultations on the Code of Conduct for Outer Space Activities was held in Luxembourg, using as their basis the fifth revised draft of the Code submitted earlier in 2014.

On 10 June, Russia and China submitted an updated draft of their proposed Treaty on the Prevention of the Placement of Weapons in Outer Space, the Threat or Use of Force against Outer Space Objects to the Conference on Disarmament. Frank A. Rose, the Deputy Assistant Secretary of State for Arms Control, Verification, and Compliance for the United States, stressed the United States’ opposition to this Treaty. He asserted that the draft did not meet necessary criteria, particularly that “there is no effective verification regime to monitor compliance, and terrestrially based anti-satellite systems posing the greatest and most imminent threat to space systems are not covered.”


On 20 February, experts gathered in Sydney, Australia for a forum on Off-Earth Mining. Discussions included lunar water, potential fuel and the legality of any mining operation under the Outer Space Treaty. Australia does not have a space agency but does house some of the world’s largest mining companies; hence the keen interest in the next mining frontier. The first of its kind, the goal of the conference was to establish dialogue regarding the feasibility of placing a self-sustained, mechanized mining colony on the Moon.

On 8 March Lithuania acceded to the Outer Space Treaty and became the 102nd member.


The fifty-first session of the Legal Subcommittee of the Committee on the Peaceful Uses of Outer Space was held from 19-30 March 2012 in Vienna, Austria, during which Chair highlighted the instrumental role of the Subcommittee in the development and further advancement of the international legal regime governing the activities of States in the exploration and use of outer space over the past 50 years. Delegates expressed the view that a lacuna existed in the current legal regime governing outer space with regard to the possible introduction of weapons into outer space, thus their aim is to eliminate the deficiency and strengthening of the current legal regime to ensure safety, security and transparency in the conduct of space activities.

On 12 April, the Democratic People’s Republic of korea failed to launcha satellite in commemoration of the late Kim Il Sung’s 100th birthday and in line with the Outeer Space Treaty’s peaceful exploration clause. The Kwangmyongsong-3 rocket broke into approximately 20 pieces which landed in the sea west of Seoul. The DPRK stated that the rocket was intended to lift a ssatellite in to space but western nations are not convinced of its true purpose due to past nuclear weapns work. The launch broke two UNSC resolutions for a second time (1718, 1874) which demand the DPRK halt all rocket launches and activities related to its ballistic missile program.


On 8 February, the Conference on Disarmament met to discuss the prevention of an arms race in outer space. China and Russia brought forward the 2008 draft treaty on the prevention of placement of weapons in outer space, which was welcomed by some states while the United States reiterated its reservations about the proposed text.

On 7 March, the United States attempted to launch a satellite that would contribute to observations of the Earth’s atmosphere; however, it crashed into the Pacific Ocean before it achieved orbit.

On March 15, Iran reported successfully launching a rocket dubbed Kavoshgar-4 with a test capsule meant to sustain life in orbit.

On 15 June, Iran successfully placed the satellite Rasad into orbit for the second time. Rasad will be used for topography missions and high-resolution mapping. Iran launched the satellite on a two-stage Safir-1B rocket, which may constitute a violation of UN Security Resolution 1929 prohibiting Iran from taking any actions related to nuclear-capable ballistic missiles.

On 12 September, the United Nations General Assembly adopted Resolution 66/71 on international cooperation in the peaceful uses of outer space. The Resolution reaffirmed the importance of continued progress in cooperation in outer space.



On 3 February, Iran reported successfully launching into space a rocket carrying a mouse, two turtles, and worms. This comes as part of Iran’s efforts to demonstrate technological parity with the West, and raises concerns about Iran’s developing ballistic missile capabilities.

On 19 June, the Russian government called upon the United States to halt any consideration of fielding space-based weaponry linked to missile defense. According to Russian Deputy Defense Minister Vladimir Popovkin, because satellites can be easily shot down, there is no need to rely on a space-based missile defense system.

On June 29, U.S. President Barack Obama released his administration’s official space policy. This document indicated that the United States would “consider proposals and concepts for arms control measures if they are equitable, effectively verifiable, and enhance the national security of the United States and its allies.”

On 27 September, the European Union issued a draft Code of Conduct for Outer Space activities, which contains voluntary guidelines to minimize harmful interference, collisions, or accidents as well as debris in outer space. The draft, revised in October, is intended to be the basis for further consultations with third countries.


On 2 February, Iran launched into orbit its first indigenous satellite, carried by Safr-2 rocket. The telecommunications satellite is called Omid (Hope) and reportedly weighs 27 kg. The successful satellite launch makes Iran the tenth country in the world with a capability to place its own satellites into orbit. The launch provoked concerned reactions from the West, with the U.S. State Department expressing “grave concern” and the German foreign minister calling it a “worrying development.”

On 3 March, the DPRK signed the Outer Space Treaty. On 4 April the DPRK launched a long-range Taepodong-2 missile that reportedly contained a satellite payload. According to United States Northern Command, stage one of the missile fell into the Sea of Japan/ East Sea, while the remaining stages along with the payload landed in the Pacific Ocean. The DPRK government claimed that the launch was justified by the wording of the Treaty, which states that space “shall be free for exploration and use by all states without discrimination of any kind.” Many states, including the Republic of Korea, claimed that the DPRK violated UN Security Council Resolution 1718, which demands that the DPRK not conduct any further missile launches.

On 5 March, Russian Deputy Defense Minister General Valentin Popovkin announced that the Russian Federation is developing anti-satellite technologies. On 13 May, the Russian President Dmitry Medvedev approved the new national security strategy, which will be followed until 2020. This report criticizes unidentified states for seeking the “unilateral formation of a global missile defense system” and the “militarization of outer space.”

On 6 May and 8 July, the United States launched two satellites into space that are intended to detect and track missile flights. The U.S. Missile Defense Agency claims that the completed satellite network will be capable of continuously tracking strategic or tactical missiles in order to allow U.S. missile defense systems to bring them down with interceptors.


On 20 February, the United States destroyed a non-functioning National Reconnaissance Office satellite using a modified tactical Standard Missile-3 (SM-3) launched from an AEGIS cruiser. Ambassador Christina Rocca addressed the issue on 15 February in the Conference on Disarmament, claiming that the action would be consistent with the Outer Space Treaty as the United States had notified foreign governments in advance in the interest of transparency and was carrying out the operation to prevent the possible loss of life.


On 11 January, China conducted the first successful test of its anti-satellite (ASAT) system by successfully using a ground-based medium-range ballistic missile to destroy an old Chinese weather satellite. This move was in contradiction to years of Chinese statements calling for a ban on weapons in space at the Conference on Disarmament. In response, the United States lodged a formal diplomatic protest claiming, among other things, that the test violated the intent and spirit of the Space Treaty but reiterated its position that there is no arms race in space and therefore, no reason to negotiate on PAROS or any new treaty with regards to the weaponization of space.


In August 2006, US President George Bush authorized the new U.S. Space Policy. In the document unveiled to the public on 6 October, Washington emphasized its right to “freedom of action in space” saying it will “deter others from either impeding those rights or developing capabilities intended to do so.” The policy supports the use of nuclear power in space. The policy also asserts the right to “deny, if necessary, adversaries the use of space capabilities hostile to U.S. national interests.”

At the 2006 First Committee Meeting, the “Prevention of an arms race in outer space” (Egypt, 61/58), as in years past, continued to express the hope that an ad hoc committee would be established within the Conference on Disarmament to reinvigorate the debate on the adoption of a legally binding document relating to the weaponization of outer space. The United States, however, was the only delegation to vote against and continues to oppose attempts to create such a document, arguing that the existing multilateral arms control regime is sufficient and that there is no need to address a “non-existent threat.”

The “Transparency and confidence-building in outer space activities” (Russia, 61/75) resolution was adopted by an overwhelming majority of 167 yes votes, with only the United States voting against and Israel abstaining. The United States restated its standard position that there is no arms race in outer space or intent to weaponize outer space and, consequently, no need exists for a new instrument to address the issue.



During the UNGA 60th session Member States adopted several resolutions regarding the use of outer space. A/RES/60/54 was adopted to prevent an arms race in outer space, however, the U.S. and Israel abstained. A/RES/60/66 demonstrated the Member States’ dedication to transparency and confidence-building measures in outer space activities. Only the United States voted no and Israel abstained. They also adopted A/RES/60/99 “International cooperation in the peaceful uses of outer space” by acclimation.


In the United Nations General Assembly, 178 countries voted in favor of the PAROS resolution to reserve space for peaceful purposes. No countries voted against the resolution. Only four states—Israel, Haiti, Palau, and the United States—abstained from voting.


The Resolution, “Prevention of an arms race in outer space” (Sri Lanka, 58/36), calls on all states to contribute actively to the objective of the peaceful use of outer space and to refrain from actions contrary to that objective. The CD is invited to establish an ad hoc committee on this issue as early as possible.


At the 2002 session of the Conference on Disarmament (CD), the prevention of an arms race in outer space (PAROS) remained one of the controversial issues that kept the CD from agreeing on a program of work. The President of the Conference, Ambassador Reimaa of Finland, presented a draft program of work to the CD at the end of the first part of the 2002 session that envisaged the establishment, for the duration of one year, of four Ad Hoc Committees, including one on PAROS. China and Russia, together with other delegations, presented on 27 June 2002, a working paper on the possible elements of a treaty on PAROS. Establishing an Ad Hoc Committee on PAROS was part of a proposal on a program of work presented by the former presidents of the CD in August 2002, but there was no consensus among the delegations on this item.


During the 2001 CD session, Russia proposed the establishment of an Ad Hoc Committee on PAROS, to “negotiate with a view to reaching agreement on a regime capable of preventing an arms race in outer space.” This regime could take the form of an internationally legally binding instrument. China also supported the Russian proposal and submitted a working paper outlining the basic provisions that the “Treaty on the Prevention of the Weaponization of Outer Space” should contain. China’s ambassador mentioned that the weaponization of space was “by no means a remote issue”; instead, the “danger was imminent and the issue most urgent.” The United States ambassador, on the other hand, made a few statements stressing that the United States “did not think outer space issues were ripe for negotiations” since, according to the United States, there is “no arms race” in outer space.


In 1997 the UNGA adopted a resolution on the prevention of an arms race in outer space (52/37), which reaffirmed the importance and urgency of preventing an international arms race in outer space and the readiness of all States to contribute to that common objective. The 1998 resolution (53/76) reiterated the former and emphasized the need for further measures, with verification, to prevent an arms race in outer space. The resolution stated that the CD has the primary role in negotiating multilateral agreements, including those on PAROS. It also called for the re-establishment of the Ad Hoc Committee of the CD. Furthermore, it urged States that conduct activities in outer space to keep the CD updated on any progress on bilateral or multilateral negotiations on the matter. The UNGA resolution of 1999 (54/53) reiterated the above objectives, while calling for the re-establishment of the Ad Hoc Committee of the CD in 2000.


The 1995 and 1996 regular sessions of the UNGA again affirmed the need to consolidate the regime, and requested that the CD re-establish an Ad Hoc Committee on the subject (50/69).


The 1994 regular session of the UNGA reaffirmed that there is a need to consolidate and reinforce the legal regime applicable to outer space; emphasized the necessity of further measures with appropriate and effective provisions for verification; and requested the CD to intensify its consideration of the question of the prevention of an arms race in outer space in all its aspects (49/74).


In 1993, a UN study on the application of confidence-building measures in outer space was concluded and submitted to the UNGA (48/305), pursuant to its resolution of December 1990. The group of governmental experts commissioned to prepare the study concluded that since the Outer Space Treaty was adopted in 1967, “legal norms may have to be developed further, whenever appropriate, to address new developments in space technology and increasing universal interest in its application.” Thus, the need to formulate a framework for the enhancement of cooperation and confidence-building among States was identified. The 1993 regular session of the UNGA commended this study to the attention of all UN members.

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