‘To boldly go where no man has gone before.” So ended “The Captain’s Oath” that opened most episodes of “Star Trek.” 

For years, Americans happily suspended disbelief to watch the crew of the starship Enterprise as they roamed the universe on an epic journey of discovery. Yet for decades, people considered the deployment of space-based missile defense to be the stuff of science fiction. 

That view began to dissolve on March 23, 1983, when President Ronald Reagan announced a new mission for the United States: the “ultimate goal of eliminating the threat posed by strategic nuclear missiles.” A year later, the nation stood up the Strategic Defense Initiative Organization (SDIO), dedicated solely to the task of making nuclear-armed ballistic missiles “impotent and obsolete.” 

Despite initial skepticism, SDIO funded research on the boost surveillance and tracking system, directed-energy weapons, ground-based interceptors, radars, command and control systems, and space-based interceptors. Significant progress was made in each of these fields. Yet the program as envisioned by President Reagan was not fully implemented. 

The collapse of the Soviet Union, coupled with an ebullient, post-Cold War optimism regarding the state of international security, led U.S. investment in a national missile defense system to dwindle. America downscaled its missile defense program and pursued a new concept, Global Protection Against Limited Strikes (GPALS). Rather than focusing on missile defense capable of shooting down a large majority of Soviet ballistic missiles, the U.S. designed GPALS to be able to shoot down about 200 re-entry vehicles — the number that a rogue Russian strategic submarine commander could launch. Accidental launch and limited ballistic missile attack became the name of the game in the new environment marked by rapid changes and the spread of ballistic missile and nuclear weapon technologies. 

Massive improvements in computer chips, optics and miniaturization allowed U.S. engineers and scientists to continue and advance Reagan-era space-based interceptor concepts. These improvements led to the development of the Brilliant Pebbles system, the core of GPALS. Each 45-kilogram space-deployed Brilliant Pebble would have its own “eyes” and “brain” to execute its mission: to protect the U.S. and allies from incoming ballistic missiles. The interceptor would strike incoming missiles in the boost phase, when missiles are at their slowest and have not yet deployed countermeasures. In the early 1990s, the U.S. and the Soviet Union even discussed sharing this protection. 

Congressional budget cuts to the program prompted the SDIO and NASA to send a joint probe, Clementine, to space. In addition to providing valuable lunar data, Clementine validated some of the technologies related to the Brilliant Pebbles initiative, proving that the program was feasible. 

The rosy expectations about the end of history and eternal world peace soon proved to be misplaced. Bad actors like North Korea and Iran got busy improving their ballistic missiles, developing nuclear weapons and aggressively threatening U.S. interests at home and abroad. The Clementine mission’s success did not end congressional opposition to the Brilliant Pebbles program. Despite the advancing threat, the administration of President Bill Clinton, committed to the Anti-Ballistic Missile Treaty and arms control with Russia, terminated the program in 1994. 

Washington was not able to fully dedicate itself to providing a layered missile defense system until President George W. Bush withdrew from the Anti-Ballistic Missile Treaty following 9/11 attacks. The administration concluded that it could not rely on retaliation-based deterrence vis-à-vis unpredictable actors like North Korea and Iran armed with long-range ballistic missiles. In the following years, the U.S. greatly advanced ground- and sea-based ballistic missile defense systems, building upon the work conducted under the auspices of SDIO, which had been renamed the Ballistic Missile Defense Organization in 1993. In 2002, it was rechristened as the Missile Defense Agency. 

Today the U.S. missile defense program boasts a successful track record of intercepts in space. Yet so far the U.S. has opted not to advance the concept of space-based ballistic missile defense interceptors. General skepticism lingers that the operational concept is technologically feasible and affordable. 

Since 2001, the U.S. has funded its missile defense program at about $8 billion a year. It is not developing space-based missile interceptors. Its space-based efforts are limited to developing and fielding systems that provide for detection, tracking and surveillance, producing data that allow interceptors to discriminate between warheads and countermeasures. Just recently, the Ground-based Midcourse Defense system intercepted a target simulating a long-range ballistic missile with countermeasures using space-based and ground-based satellite data. 

But today’s ground- and sea-based missile defense systems cannot possibly protect Americans from the numbers of ballistic missiles Russia and China have. There are simply too few interceptors. Moreover, current U.S. policy precludes building missile defenses that could address Beijing’s and Moscow’s ballistic missile threat. Yet national security demands that once ballistic missiles are in the air, the U.S. should be able to intercept most or all of them, no matter where they came from and in what quantities. 

Over 20 years ago, SDIO, along with numerous studies, validated and endorsed the Brilliant Pebbles space-based interceptors. Given technological advancements, the U.S. could undoubtedly design even better miniature kill vehicles to be deployed in space. If the U.S. is to get serious about defending itself from ballistic missile attacks of all ranges and scales, it will have to revive the space-based missile defense interceptor approach.

Michaela Dodge is an analyst specializing in defense and strategic policy issues in the Heritage Foundation’s Douglas and Sarah Allison Center for Foreign and National Security Policy.