It sounds like something from a James Bond movie: a massive satellite, the largest ever launched, equipped with a powerful laser to take out the American anti-missile shield in advance of a Soviet first strike. It was real, though—or at least the plan was. In fact, when Soviet President Mikhail Gorbachev walked out of the October 1986 summit in Reykjavik, Iceland, because President Ronald Reagan wouldn't abandon his Strategic Defense Initiative, or SDI, the Soviets were closer to fielding a space-based weapon than the United States was. Less than a year later, as the world continued to criticize Reagan for his "Star Wars" concept, the Soviet Union launched a test satellite for its own space-based laser system, which failed to reach orbit. Had it succeeded, the cold war might have taken a different turn.

The spacecraft was known as Polyus-Skif. "Polyus" is Russian for "pole," as in the north pole. "Skif" referred to the Scythians, an ancient tribe of warriors in central Asia—and the European equivalent of "barbarian."

According to Soviet space scholar Asif Siddiqi, a historian at Fordham University in New York City, Moscow began working on space-based weapons well before Reagan kicked the U.S. program into high gear with his March 23, 1983 Star Wars speech. "[The Soviets] funded two massive R&D studies in the late 1970s and early 1980s to explore how to counter imaginary American missile defense ideas," he says. Two concepts emerged: Skif—a laser "cannon" in orbit—and another weapon known as Kaskad (Cascade), designed to destroy an enemy's satellites with missiles fired from another craft in orbit.

Although some details about these programs leaked out in the mid-1990s, it was not until a few years ago, says Siddiqi, that the full extent of the space weapon plans became known, even in Russia. A former press officer in the Russian space industry, Konstantin Lantratov, pieced together the history of Polyus-Skif. "Lantratov managed to dig deep into the story, and his research clearly shows the enormous scale of these battle station projects," Siddiqi says. "These were not sideline efforts; this was a real space weapons program."

Design work began in the 1970s, not long after the symbolic Apollo-Soyuz "handshake in space" between NASA astronauts and Soviet cosmonauts. The famed Energia organization, which had built the Soyuz crew spacecraft as well as the giant N-1 moon rocket, a program that between 1969 and 1972 suffered four explosions, started studying both the Skif and the Kaskad concepts in 1976. Initially, Energia's plan was to use space-based weapons to shoot down American intercontinental ballistic missiles early in flight, when they were still moving relatively slowly. The Salyut space stations, the first of which was launched in 1971, would serve as the core for either the laser-equipped Polyus spacecraft or the missile-armed Kaskad. The stations could be refueled in orbit and could house two cosmonauts for up to a week.

The designers quickly abandoned this plan, however, and with it the notion of having cosmonauts live on board the Polyus spacecraft. According to Lantratov, the Soviet Ministry of Defense determined that Soviet technology was not up to the challenge of shooting down ICBMs from space, and directed that Skif and Kaskad instead be used to disable American anti-missile satellites—which didn't yet exist, and hadn't even been approved.

Although the United States also had spent considerable amounts of money in the 1950s and 1960s trying to develop a missile defense system, by the mid-1970s this work was winding down, and during Jimmy Carter's presidency, progress on anti-missile systems was minimal. In 1972, both superpowers had signed the Anti-Ballistic Missile Treaty, which limited each to two anti-missile launch sites, one to defend the capital city and one to defend a single base from which ICBMs could be launched.

But the ABM Treaty forbade only the deployment of anti-missile weapons, not testing or development, a loophole both sides exploited. Beginning about 1980, when Reagan won the presidency, scientists at the Lawrence Livermore National Laboratory in California (among them physicist Edward Teller, the so-called father of the H-bomb), along with researchers at other federal labs and a handful of military and civilian policymakers, began looking at "directed energy" weapons—which shoot beams instead of bullets—as a way to neutralize an increasing Soviet advantage in launchers and strategic missiles.

Reagan was taken with the idea, and three years later, in a televised speech on national security, he announced a plan to build a defensive shield to "make nuclear weapons impotent and obsolete," essentially changing the nation's strategic posture from offense to defense. The proposal was immediately attacked by Democrats in Congress, who called it unworkable; it was the late Senator Ted Kennedy who tagged it with the moniker "Star Wars." Despite the skeptics, funding for missile defense increased dramatically, and reached nearly $3 billion a year by 1986.

As prominent planetary scientist and Gorbachev advisor Roald Sagdeev wrote in his 1994 memoir The Making of a Soviet Scientist, "If Americans oversold [the Strategic Defense Initiative], we Russians overbought it." In the summer after Reagan's Star Wars speech, Under Secretary of Defense Fred Iklé requested a CIA study on how the Soviets might respond. The work fell to three analysts, including Allen Thomson, a senior analyst working for the CIA's Office of Scientific and Weapons Research. Thomson had studied other Soviet military research programs, including efforts to develop directed-energy weapons and sensors for space-based submarine detection.