The United States' Development Of ASATs
Early in the race to exploit outer space, the United States took the initiative in developing ASATs. In the 1950s both the navy and the air force prepared the ground by deploying radar systems for space surveillance. In 1964 the United States became the first nation to test ASATs, relatively primitive devices using Nike-Zeus ABMs and air force Thor IRBMs. Two ground-based special-purpose ASAT systems were deployed in the Pacific in the 1960s, one of which remained operational until 1975. When the expected threat—a Soviet orbital bombardment system—did not materialize, this particular deployment was abandoned. Even under Eisenhower, U.S. studies concluded that the earth was "the best weapons carrier"; the Soviets apparently came to the same conclusion. They began to test an ASAT in 1968, stopped three years later, then resumed testing in 1976, which triggered renewed U.S. interest. President Carter attempted to negotiate a treaty designed to stop further ASAT developments. Talks were held in 1978, but the Soviets were not particularly interested. Early in the 1980s the Soviets offered to negotiate a ban on the testing of space weapons, but by then the Reagan administration was becoming committed to the development of a U.S. ASAT.
The launching of Sputnik in 1957 galvanized the U.S. space program, bringing projects to fruition. Reconnaissance satellites had been under study from early in the 1950s and had already benefited from the adoption of the recommendation of the Strategic Missile Evaluation Committee chaired by John von Neumann in the spring of 1954, which urged that the United States give "highest priority" to the development of ICBMs. Given that a rocket capable of sending a warhead an intercontinental distance can also, in general, launch a satellite of approximately the same weight, this decision meant that a sufficient launch capacity would also be available for satellites. The official, unclassified U.S. space program, however, gave initial priority to a scientific satellite, developed in 1955 under Project Vanguard. After Sputnik, however, political pressure led the Eisenhower administration to establish ARPA and then to transfer responsibility for military satellites to the services and the CIA, whose Project Corona reportedly resulted in the launching of satellites that took film and ejected the cannisters for air recovery.
Even before Sputnik, however, the air force had initiated a highly classified program of its own, called the Satellite and Missile Observation System (SAMOS), and also cooperated with the CIA's Corona program, which reportedly used air force Project Discoverer satellites. The downing of U-2 pilot Gary Powers in 1960 stimulated further increases in funding for Project SAMOS.
In general, Sputnik and the U-2 incident stimulated a new commitment to the use of space for military purposes. According to widely published reports, an organization called the National Reconnaissance Office was created in 1960. Air Force officers in particular urged that military activities in space be given high priority. Thus Gen. Bernard Schriever called on the United States to achieve "space superiority," and others argued that air and space were becoming indivisible fields of military operation. The air force made a special claim to the "space mission," though both the army and the navy put their own cases forward for control of satellites.
In the Eisenhower administration, the case for observational satellites was considered compelling. Eisenhower himself believed that because the Soviet Union was a closed society, certainly in comparison with the United States, reconnaissance satellites were crucial. Despite Soviet success with Sputnik, it was not clear at the outset that the Soviets would agree to satellite overflights. For this reason, such overflights were cloaked in secrecy. Because the United States was even more dependent than the Soviets on satellite reconnaissance, Eisenhower was reluctant
to approve the development of ASATs, inasmuch as this would give the Soviets an incentive to follow suit. He did permit exploratory development of the Satellite interceptor (SAINT) system because it was presumably designed for the interception (and inspection) of satellites rather than for their destruction.
It was well recognized, however, that U.S. satellites could not be easily protected by physical means. The United States therefore sought a politico-legal solution to their vulnerability by proposing international agreements to sanction or legitimate overflights by reconnaissance satellites. It proposed that space be used for peaceful activities, on the tacit understanding that reconnaissance satellites could be included because they were not weapons. At first the Soviets refused to agree to the proposals, but their view changed as they acquired their own reconnaissance satellites. As early as May 1960, Khrushchev expressed the view at an international meeting with other heads of state that photographic reconnaissance by satellites was permissible, even though overflights by aircraft were violations of sovereignty. At the same time, however, Soviet officials continued to object to satellite reconnaissance. In 1962 the U.S.S.R. opened a diplomatic offensive at the United Nations aimed at prohibiting such activities through the adoption of a declaration of principles holding that "the use of artificial satellites for the collection of intelligence information in the territory of foreign states is incompatible with the objectives of mankind in its conquest of outer space."
The Soviets changed their tune once their own Kosmos reconnaissance program began regular intelligence gathering and as progress was also made in the test-ban negotiations. They recognized that satellite reconnaissance could provide a way around the need for on-site inspection. By September 1963, the Soviets had ceased opposing the United States' call for legitimating satellite reconnaissance.
Meanwhile, the U.S. had not restricted its efforts only to reconnaissance satellites. Both the army and the navy developed ideas for ASATs. The army considered converting the Nike-Zeus into an anti-ballistic missile, and the navy worked on modifying the Polaris missile to serve the same purpose. The air force had the most ambitious program: in response to Soviet civil space activities, it proposed in September 1961 that the United States adopt a ten-year plan for satellite interception, space-based ballistic missile defense, a fast-reaction space bomber that could reenter the atmosphere, and a manned capability in space. The Kennedy administration rejected the proposal for a manned space facility but agreed that ASATs deserved closer consideration. This decision
was certainly reinforced by Khrushchev's threat to place bombs on orbiting Soviet satellites.
In the early 1960s McNamara took a highly secret decision to allow the army to develop a modified Nike-Zeus under the code name Mudflap, later designated Program 505. This system became operational on August 1, 1963. Earlier that year the air force was instructed to prepare an additional ASAT, using the Thor missile (alias Project 437). This was tested in February 1964. Nike-Zeus had the advantage of using a solid propellant, but the Thor could reach higher altitudes. Both were designed to use nuclear warheads, a disability inasmuch as their use would have threatened U.S. satellites in the vicinity and their testing would have violated the Limited Test Ban Treaty. Project 437 nevertheless remained in place on Johnston Island until 1975.
In 1963 the United States proposed, and the Soviets agreed, that the United Nations should issue a declaratory ban on weapons of mass destruction in outer space. The Soviet Union had already experimented with satellites designed to carry large nuclear weapons, which the United States called a Fractional Orbital Bombardment System (FOBS). But it evidently determined, as the United States had independently, that terrestrial systems were preferable for such purposes. In 1967 both nations signed a treaty banning weapons of mass destruction from placement in space. Neither the declaratory statement nor the treaty banned the development of ASATs. The United States proceeded with ASAT development as a hedge against surprise and possible Soviet abrogation of the treaty, and also in order to have the ability to attack satellites in time of war.
U.S. concerns were aroused in 1966 and 1967 by Soviet launches from Tyuratam, Kazakhstan. Apparently, the payload portion was commanded down to earth before one complete orbit. McNamara interpreted the launches as an attempt to develop FOBS satellites designed to serve as weapons carriers that would approach the United States from the south, its most vulnerable flank. To counter this threat, the United States utilized over-the-horizon radar, with increased coverage of the southern United States, and commenced development of a new ABM—the Nike X.
As early as 1958 ARPA sponsored a series of experiments called Project Argus, designed to assess certain of the effects of nuclear explosions in space. The Fishbowl series above Johnston Island in 1962 included one large nuclear explosion with a yield of 1.4 megatons; several satellites were damaged.
The navy in 1961 also proposed a direct-ascent ASAT in its modified
Polaris. The air force's SAINT had been designed as a co-orbital device, which must go through several space orbits before it achieves the same orbit as its target. So as not to give the Soviets an excuse to shoot down U.S. reconnaissance satellites, SAINT was designated an "inspection" system rather than as an interceptor. In January and February 1958, Eisenhower sent two letters to Bulganin, referred to earlier, proposing a cessation of all military activities in space, including the testing of long-range missiles. The proposal was conditioned on the creation of an international system for observing and verifying compliance. The U.S.S.R. rejected the proposal, calling it an attempt to hinder Soviet progress. In May 1962, as part of Project HiHo, the Navy test-launched a rocket from a Phantom F4D fighter bomber with a secondary objective of launching ASATs. In 1970 research began on the Miniature Homing Vehicle (MHV), the basis of the United States' current ASAT. The MHV is an air-launched heat-seeking missile that homes in on a target satellite and destroys it by force of impact. The United States has been developing this weapon since 1977, using an F-15 aircraft modified to serve as a launch platform. It is currently estimated that this ASAT could be ready for deployment in 1990 at a cost of $4 billion. Other efforts were pursued to improve space tracking and detection, which also served to improve prospects for an effective ASAT. And in the mid-1970s attention was directed to the need for an improved satellite survivability.