How the Star Wars Program Didn't Work

President Reagan suspected that the announcement of the Strategic Defense Initiative (SDI) would infuriate the Soviet Union. He was right. Despite Reagan's repeated assurances that the defense system would only be used to prevent the Soviet Union from attacking rather than giving the U.S. carte blanche to strike without consequence, Soviet leader Yuri Andropov remained unconvinced. Within a year, the Soviets were directing 70 percent of their propaganda worldwide toward maligning SDI, despite finding the program not feasible to begin with [source: Lettow].

The Soviets also pointed out that any ballistic missile defense system the United States could build would violate a number of treaties already in place. For instance, the Anti-Ballistic Missile (ABM) Treaty of 1972 limited both the United States and the Soviet Union to two (and later one) ground-based missile defense systems. The 1967 Outer Space Treaty, signed by several countries including the U.S. and the Soviet Union, banned the use of weapons of mass destruction in space.

The firestorm of criticism for Reagan's plan kept burning. European allies were concerned about how the program would affect the precarious balance of power between them and the Soviet Union. U.S. lawmakers worried that the technology needed to shoot ICBMs down midflight was simply out of reach and not worth pursuing. These fears from home and abroad introduced some serious tension into negotiations among all parties involved. Still, despite serious pressure to put SDI on the bargaining table in an effort to get the Soviet Union to reduce its nuclear armament, Reagan refused to compromise the program.

Subsequent presidents, however, were quick to modify and cut the program. President George H.W. Bush initiated a review of SDI shortly after the start of his term, ultimately deciding to refocus the program and drastically cut back its scope. Granted, by this time the Soviet Union had collapsed, diminishing the threat of large-scale nuclear war. Rapidly rising costs and relatively few tangible results had also made the program more unpopular than ever. President Bill Clinton further refined the scope of the project, and before long, the United States' missile defense programs looked very little like what Reagan envisioned when he announced the program. Of course, things might have gone very differently for SDI had the technological aspects of the program not been so daunting.

Read on to see exactly how SDI hoped to shoot down nuclear missiles, and how those hopes never quite turned into reality.

MIRACL, SSTS, BSTS, CHECMATE and ERINT -- all were systems designed to take down ICBMs as part of the Strategic Defense Initiative (SDI). The acronyms alone are enough to make your head spin and only hint at how complex and difficult building a missile defense shield truly was and is. Not only did the system have to detect when a missile launch occurred, it also had to track the missiles in flight, communicate that information to the weapons poised to shoot down those missiles, and finally, aim and fire those weapons to score directs hit on fast-moving targets.

To make matters even more complicated, the Soviets could add missile decoys, overwhelm the system by building more ICBMs or even take aim at the defense system itself, incapacitating it before launching a nuclear attack in the first place. And finally, certain technologies were off the table from the start thanks to restrictions outlined in the ABM and Outer Space treaties.

Still, scientists and engineers heading up SDI came up with several promising approaches shortly after the program received funding, and many of them lived up to the "Star Wars" moniker. The press particularly enjoyed focusing on the X-ray laser, a weapon seemingly ripped out of the pages of a science-fiction novel. The laser, proposed by renowned physicist Edward Teller, was designed to orbit the Earth, where it could shoot down multiple Soviet ICBMs simultaneously using power generated by a nuclear blast. Initial testing of the technology provided disappointing results, however. By the late 1980s, the X-ray laser was scrapped, but not before becoming a symbol for the impracticality and expense of the "Star Wars" program.

Other approaches to destroying Soviet ICBMs included so-called kinetic warheads that would collide with ICBMs in orbit and destroy them, satellite-mounted rail guns that were ultimately scrapped for requiring huge energy reserves to operate and the MIRACL laser that scientists hoped to shoot off of ground-based mirrors at moving targets. Critics of SDI are quick to point out how few of these approaches amounted to anything, but in fact, SDI was set up to explore every alternative from the start and pursue only the most promising of the candidates. Unfortunately, even after billions of dollars were spent developing these technologies, SDI had yet to shoot down a single ballistic missile in flight [source: New Scientist]. And before the technologies could be refined and modified to take advantage of ever-increasing computing and tracking systems, the Cold War had ended and "Star Wars" was phased out for a new approach to missile defense.

Looking back, it's easy to criticize Reagan's "Star Wars" program as impractical and perhaps even reckless. It never came close to helping rid the world of nuclear weapons as Reagan hoped it would, but the Strategic Defense Initiative (SDI) wasn't a complete bust. Many argue that SDI forced the Soviet Union to stretch its defense spending to the breaking point to match the United States' efforts, ultimately leading to the end of the Cold War.

SDI also forced a new round of negotiations on nuclear arms reduction between the two countries, culminating in the signing of the Intermediate-Range Nuclear Forces Treaty and the dismantling of thousands of conventional and nuclear weapons [source: Federation of American Scientists]. And while many people are quick to point out how slowly SDI progressed, President Reagan declared from the outset that a working missile defense might not materialize until the next century. We can only guess whether SDI would have started producing results throughout the '90s had it been continued.

We do know, however, that SDI fundamentally changed the United States' approach to missile defense. Since the "Star Wars" program was phased out in favor of more targeted and limited missile defense, the U.S. has continued to make slow and steady gains in its ability to destroy a small number of long-range missiles in flight. In 2011, the closest equivalent to SDI is the Ballistic Missile Defense System (BMDS) developed under the U.S. Missile Defense Agency designed to destroy the sorts of small-scale missile strikes that might originate from rogue nations and terrorist organizations. In addition to developing incredibly advanced tracking and targeting systems, the program has created both land- and sea-based missile defense systems. Working with Boeing, the agency has even found some success using plane-mounted chemical lasers to destroy a ballistic missile during its launch. So, while the technologies behind BMDS don't involve nuclear-powered space lasers and the like, the program would likely be far behind where it is today if it weren't for Reagan's dogged determination to build a missile defense system decades earlier.

What's more, the U.S. Missile Defense Agency is taking steps to carry out Reagan's vision of an international missile defense system. Currently, the agency is working with countries throughout the world on developing missile defense technology, installing tracking and detection systems, and creating support for the program. So while missile defense may never lead to a world free of nuclear weapons, some might argue that it's well on its way to making the world a safer place, and we have "Star Wars" to thank.