As companies and countries clamor to launch satellites and manned spacecraft, space is getting ever more crowded. And because satellites play increasingly important roles in military operations, multiple governments are developing anti-satellite (ASAT) weapons.
But debris generated by anti-satellite weapons tests, like the one Russia conducted late last year, poses a significant threat to use of space, whether by militaries or private enterprises. Since 2007, the United States, China, and India have also carried out debris-producing activities, creating a hazardous environment for satellites and human spaceflight. While many experts agree that debris-producing weapons tests in space should be prohibited, very little progress has been made toward achieving this goal.
There’s a key obstacle in the way of formal anti-satellite weapons limits: Many countries around the world are developing missile defense systems, and several of the technologies used in missile defense are applicable to anti-satellite weapons.
In the last two decades of the Cold War, the United States and the Soviet Union went through multiple rounds of arms control negotiations that included discussions specifically aimed at limits on anti-satellite weapons. While Moscow and Washington made significant progress on nuclear arms reductions, talks about the “controlled use of space” did not lead to anti-satellite arms control agreements.
But there is a path toward eliminating the damage of the space weapons tests without limiting weapons technologies that can be used as anti-satellite weapons: A ban on debris-generating anti-satellite testing in space. Such a ban would be verifiable and circumvent the difficulty of eliminating whole categories of weapons technologies.
Anti-satellite weapons and the Cold War. In the summer of 1960, the United States successfully launched its first imagery intelligence satellite, called Corona, into orbit. On its first mission, Corona imaged more of the Soviet Union than all of the previous U-2 reconnaissance plane flights combined. Very quickly, satellites became the largest source of intelligence on the Soviet Union. American national security leaders feared that a US anti-satellite weapon program would have risked spurring the Soviets to act aggressively against US space systems, putting vulnerable intelligence satellites at risk. To this end, President Dwight Eisenhower set the precedent of pursuing an international political framework that would ensure the viability of satellite reconnaissance.
But anxiety about orbital nuclear weapons prompted the US government to embrace a hedge. Fearful of the potential for Soviet space-based nuclear weapons, President John F. Kennedy, approved a land-based nuclear-tipped anti-satellite weapons system called Program 437. By the time of the program was established, US scientists had already learned that high-altitude nuclear detonations could damage or destroy American satellites. Officials believed that Program 437 was of very limited utility.
In Moscow, however, Program 437 was likely used as a justification to accelerate its own anti-satellite weapons effort aimed at having the capability to destroy US military and intelligence satellites. By the late 1960s, the United States and the Soviet Union both recognized the legitimacy of overflights from space. At this same time, the Soviets, however, had begun testing a non-nuclear co-orbital anti-satellite system.
Not wanting to undermine the American-Soviet arms control talks, President Richard Nixon refused to approve a new anti-satellite weapons program in response to the Soviet effort. Largely due to ongoing arms control negotiations, the Soviet Union ceased testing anti-satellite weapons in space in 1971, lowering tensions over space security. When in 1972 the United States and the Soviet Union signed the Anti-Ballistic Missile Treaty and the Strategic Arms Limitation Treaty, they included a provision that neither party would interfere with the other’s reconnaissance satellites, which were used to monitor treaty compliance.
But the calm wouldn’t last long.
The Soviets resumed testing in 1975, and President Gerald Ford ordered a reexamination of US anti-satellite weapons policy. Prominent American physicist Solomon Buchsbaum would oversee the review. Buchsbaum maintained that satellites would increasingly play essential roles in supporting tactical military operations and would therefore be critical targets in a wartime situation. The review noted that Soviet satellites used to support naval targeting provided reason enough for the United States to begin developing a new space weapons.
Primarily due to the growing tactical use of military space systems, Buchsbaum concluded that “treating space as a sanctuary [was] neither enforceable nor verifiable” and that “the Soviets should not be allowed an exclusive sanctuary in space.” Ford embraced these findings, and in his final days in office, he signed a national security memorandum directing the creation of a new anti-satellite weapons program.
Buchsbaum and his team, nevertheless, maintained that it was worthwhile to consider arms control proposals that would limit anti-satellite weapons designed to attack higher-attitude satellites that were used for nuclear command and control and early warning. It would be left up to Jimmy Carter to decide how to proceed on anti-satellite weapons arms control.
Shortly after his arrival in the White House, Carter made securing a new arms control treaty with the Soviet Union a top priority. Since the treaty would rely on satellites for verification, Carter believed unfettered development of anti-satellite weapons could undermine treaty ratification. He wanted to completely ban anti-satellite systems and maintained that the benefits of getting rid of them outweighed the Ford administration’s favored arguments about the utility of the weapons in wartime. The Pentagon warned that verification of anti-satellite limits would be a significant challenge because it would be difficult to monitor all Soviet military hardware with anti-satellite applications. To address this problem, US officials recommended banning dedicated weapons, but not systems with residual anti-satellite capabilities, e.g., missile defenses that did not have a primary anti-satellite mission.
During the Carter administration, the United States and the Soviet Union went through multiple rounds of anti-satellite weapons talks in 1978 and 1979. The parties disagreed over definitions; Soviet negotiators, for example, wanted the United States to place limits on the space shuttle because they deemed it anti-satellite capable, but US officials refused to put the shuttle on the negotiating table. To place added pressure on Moscow, Carter authorized the Pentagon to move ahead with anti-satellite weapons development, including tests in space, though no debris-producing tests would be conducted while he was president.
Despite disagreements, Moscow and Washington were making progress towards agreeing to a moratorium on testing anti-satellite weapons in space, along with a prohibition on displacing each other’s satellites. In essence, even though the two sides were unable to agree to limits on anti-satellite or anti-satellite-capable weapons, a ban on certain behaviors, i.e., debris-producing tests and physical interference with satellites, was a possibility. But world events interrupted the diplomatic progress. After the Soviet Union invaded Afghanistan in 1979, the talks stalled.
In stark contrast to Carter, President Ronald Reagan embraced the military utility of anti-satellite weapons; his administration publicly identified their importance for denying the Soviet Union the use of space and for deterring attacks against US satellites. And Reagan sought expeditious development of an air-launched anti-satellite weapon, commissioning a study for implementing his national space policy based on the premise that the Soviet Union had “initiated a major campaign to capture the ‘high ground’ of space.”
The most significant space-related development during Reagan’s presidency was his establishment of the Strategic Defense Initiative, a research program to develop the technologies for land- and space-based missile defense. Shortly after the president announced the program in March 1983, the Soviet Union proposed a moratorium on anti-satellite weapons testing that would eventually lead to their dismantlement. Because anti-satellite weapons and space-based missile defense relied on many of the same technologies, the Soviet proposal to limit anti-satellite systems would have constrained the Strategic Defense Initiative.
Despite the Reagan administration’s emphasis on the military value of anti-satellite weapons, recently declassified documents reveal that in 1984 the president was considering proposing a treaty that would limit offensive space weapons, i.e., anti-satellite systems, and allow defensive ones, i.e., space-based missile defense. Reagan told his senior advisors that “we should first talk about getting rid of these offensive arms like this F-15 [anti-satellite weapons]. We must make it clear that we are not seeking advantage, only defense.” He said, moreover, that the United States was “willing to negotiate the end of [anti-satellite weapons] because they are offensive weapons. [Strategic Defense Initiative] is a non-nuclear defensive system.”
Chief of Naval Operations Admiral James Watkins replied that the planned air-launched anti-satellite weapon was “not the answer to the military’s prayer” and could “be given up, from a military point of view, but it must be remembered that this is closely related to [the Strategic Defense Initiative].” Other members of Reagan’s national security team explained that the Strategic Defense Initiative’s interceptors could also serve as anti-satellite weapons, and that it was therefore impossible to distinguish between offensive and defensive space weapons.
At this same time, Kenneth Adelman, the head of the Arms Control and Disarmament Agency, an independent agency of the US government that focused on arms control negotiation and implementation until its dissolution in 1999, recommended negotiating “rules of the road” that would establish boundaries for military activities in space, but this was not positively received by other administration officials. Members of an inter-agency anti-satellite weapons working group considered multiple arms control options, including a ban on high-altitude systems and new generations of low-altitude systems, but the Department of Defense was vehemently opposed to any form of space arms control because of its plans for more sophisticated anti-satellite weapons and because of the potential impact on the Strategic Defense Initiative.
Because preserving the Strategic Defense Initiative was a top priority, Reagan ended up rejecting any limits on anti-satellite weapons. In 1985, the United States conducted the first and only test of its air-launched, Miniature Homing Vehicle system that included destruction of a US satellite. But due to congressional opposition to anti-satellite weapons, lawmakers prohibited further debris-producing tests and the Pentagon cancelled the Miniature Homing Vehicle program in 1988.
Anti-satellite weapons after the Cold War. After the Cold War came to an end, the US government cut funding for space-based missile defense and anti-satellite weapons. The Russian Federation moved its anti-satellite weapons programs into a mothballed status and focused on other priorities. In these changing geopolitical circumstances, restraint in space was restored, but this was a tenuous situation at best.
Though Moscow and Washington had made significant progress on nuclear arms reductions in the Nuclear and Space Talks of the 1980s, they did not agree to any new binding measures regarding the use of space for military purposes.
The United States demonstrated that space systems were essential for modern warfare during the first Gulf War, which also highlighted the reality that satellites were a key vulnerability for US national security. To ensure unfettered access to space in wartime, Air Force Vice Chief of Staff General Thomas Moorman advocated that the United States develop the means for militarily controlling space.
Because of US dependence on space systems, the federal government commissioned a special panel to reexamine the organization and management of the American national security space enterprise. The panel’s chair, Donald Rumsfeld, warned of the potential for a “Pearl Harbor in space” and that space security, therefore, demanded renewed focus. When former President George W. Bush selected Rumsfeld as his secretary of defense, the president was choosing someone with a long history of endorsing space control capabilities.
The linkage between missile defense and anti-satellite weapons would once again become a key problem for space security in the post-Cold War era. The first really significant development for space security in the 21st century was Bush’s announcement in 2001 that the United States would withdraw from the 1972 Anti-Ballistic Missile Treaty, citing concerns about “rogue states” like North Korea and Iran. This move contributed to the proliferation of missile defense systems, which, of course, could also be used as anti-satellite weapons.
A watershed moment in space security was a 2007 Chinese weapons test that produced significant debris in low earth orbit. This was the first debris-generating anti-satellite weapons test in over 20 years. The tacit norm of not conducting destructive weapons tests in space was shattered. According to media reports, the Bush administration knew of the test ahead of time but said nothing in order to “maintain maximum flexibility for developing antimissile defenses.” Washington, along with diplomats from around the world, resolutely condemned the test.
Approximately one year after the Chinese test, the United States executed Operation Burnt Frost, which involved shooting down a US satellite that had reached its end of life. The Bush administration had determined that the satellite’s toxic hydrazine posed a significant environmental risk and ordered the Pentagon to destroy it. The Navy used an SM-3 missile, designed for missile defense, to eviscerate the satellite shortly before reentry to minimize debris generation. Even though the operation was officially due to health and safety concerns, its occurrence so soon after the Chinese demonstration made the US action appear to be a response to Beijing.
Even though then-Vice Chairman of the Joint Chiefs General James Cartwright described the use of the SM-3 in an anti-satellite role as “a one-time deal,” the current director of the Missile Defense Agency, Vice Admiral John Hill, recently referred to the SM-3 as a “space weapon.”
In recognition of the changing space security environment, the Obama administration declared that space was “congested, contested, and competitive,” a policy position that, harkened back to the late 1970s, when Carter recognized that the United States and the Soviet Union were moving towards making space into a potential battleground.
But former President Barrack Obama did not, however, take meaningful steps towards engaging with the international community to constrain either the development or testing of anti-satellite weapons. The administration rejected the European Union’s proposed Space Code of Conduct, which emphasized freedom of access to space, among other areas, describing it as “too restrictive.” In other words, there was concern that agreeing to the non-binding code of conduct could box in US military space activities and plans. Obama did not reinvigorate the country’s anti-satellite efforts in response to space security concerns, but he also did not act to curb the harmful effects of anti-satellite weapons testing in space.
In certain key areas, former President Donald Trump’s national security space policy recycled the space language of the Reagan administration. Trump famously created the US Space Force as an independent service and called for “projecting military power in, from, and to space.” Space, Trump said, is “going to be a very big part of our defense and offense,” insisting on the need for space-based missile defense. During Trump’s presidency, the Department of Defense began to formally refer to space as a warfighting domain. Despite these re-organizations and introduction of more aggressive space policy language, the United States has focused on developing technologies that wouldn’t physically destroy satellites, electronic warfare capabilities for instance.
After India, an important US partner, destroyed one of its own satellites in 2019, the then-Acting Secretary of Defense Patrick Shanahan called for developing “rules of the road” for space. But just as in the 1980s, diplomatic engagement on norms development in space was not an administration priority.
In his first year in office, President Joe Biden has had to contend with Russia’s first debris-producing anti-satellite weapons test in the 21st century. Moscow has conducted multiple tests that did not involve destroying a space object, and it is not yet clear why the Russian government conducted this particular test, especially when it could have endangered astronauts and Russian cosmonauts on the International Space Station. Perhaps the test was a “screw up” and the Russians did not intend to intercept the target in a way that produced so much debris. Regardless, the test incident highlighted the reality that debris produced by anti-satellite weapons is a serious threat to commercial, civil, and national security space operations, a reality that has been proven time and time again since the Cold War.
Deputy Secretary of Defense Kathleen Hicks has called for an end to debris-producing anti-satellite weapons tests. Biden’s nominee to become the assistant secretary of defense for space policy, John Plumb, similarly backs a moratorium on destructive testing of the space weapons. It’s time to make an international agreement banning debris-generating anti-satellite weapons tests a top administration priority.
Learning from the past. The present space security environment is similar to the situation in the late 1970s and 1980s, but also different in key respects. The US government is once again openly discussing concerns about the vulnerability of space systems, along with the potential for military action to, in, and from space. Key differences are that anti-satellite weapons technologies have significantly progressed and the number of countries and commercial entities operating in space has grown exponentially. During the Cold War, space security was primarily defined by US-Soviet engagement, but bilateral arrangements will be insufficient for the present situation.
Because space systems play such important roles in modern warfare, it is only to be expected that militaries around the world will develop the means to interfere with satellites in wartime. Many countries are investing more in missile defense capabilities that can be used as anti-satellite weapons as well. Israel, for example, has alluded to the fact that it could use its Arrow system in an anti-satellite weapons role if needed in the future. Due to this situation, the missile defense-anti-satellite weapons “entanglement” continues to be a significant problem and an impediment to limits on the weapons. All hope is not, however, lost.
A key lesson from the Cold War is that proposals aimed at limiting behaviors in space are likely to be more easily achieved than attempting to limit or ban whole classes of weapons systems with anti-satellite applications. The United States and the Soviet Union discussed anti-satellite limits multiple times, but definitional differences and concerns over verification stymied progress. It is, nevertheless, very well possible that had the American-Soviet anti-satellite weapons talks continued past 1979 a mutual testing moratorium would have been achieved. For the United States in the 1980s, the fact that anti-satellite weapons constraints would have limited missile defense development was the primary problem. At different points in time, Moscow and Washington did, however, limit their respective testing activities in space.
This emphasis on banning debris-producing space tests in no way suggests that other space arms control proposals should not be considered or pursued. For example, discussions aimed at preventing kinetic and non-kinetic interference with satellites used for nuclear command and control and early warning could reduce the likelihood of nuclear escalation. But the objective here is to secure an agreement, in the near term, that will lead to a more sustainable space environment.
Securing formal constraints on dual-use technologies with anti-satellite weapons applications is going to be a long-term and uphill battle. To promote stability in space, the United States, Russia, China, India, and other countries should focus on finally establishing a prohibition against debris-producing tests. This will, at the very least, prevent the further generation of harmful debris in space due to weapons testing. It is indeed verifiable and overcomes the political challenges associated with securing a multi-party arms control agreement that bans specific weapons systems that can be used as anti-satellite weapons. Developing rules of the road for space has long been on the diplomatic agenda, and it is time to act before debris-producing tests become a behavioral norm.