Since the advent of intercontinental ballistic missiles in the 1950s, military scientists and engineers have been working hard to find a way to defeat them. Yet after decades of research and billions of dollars in investment, intercepting an incoming intercontinental ballistic missile, or “hitting a bullet with another bullet”, as it’s often described, still cannot be done reliably.
In a test last month, for instance, a US ground-based interceptor failed to take down a missile, marking another defeat for a system that has had, to date, a mixed record at best.
Ironically, that ground-based missile defense system, which uses a so-called “hit to kill” approach, where the amount of destructive energy released on impact disables or destroys the intercepted missile, is less ambitious and seemingly more practical than missile defense schemes of years past. Previous attempts often involved exotic directed-energy weapons and Death Star-like complexity. What follows is a partial list of the most outlandish ideas:
Excalibur (Cancelled 1992)
It was perhaps the grandest missile defense scheme of all time: A space-based nuclear-pumped X-ray laser that would blast large numbers of intercontinental ballistic missiles. The cornerstone of President Ronald Reagan’s Strategic Defense Initiative, Project Excalibur was, in theory, capable of protecting against a large-scale nuclear attack from the Soviet Union. After about ten ground-based tests, however, the project was cancelled.
Brilliant Pebbles (Cancelled 1993)
Another ambitious missile defense scheme proposed under the Reagan-era missile defense effort was the concept of launching missile-killing mini-satellites, each about the size and shape of an American football. Like the Excalibur laser, it was criticised for its technical complexity and cost. In theory, the mini-satellites would hone in on and collide with ballistic missiles as they travelled outside the Earth’s atmosphere. It was eventually cancelled when the Reagan-era projects were scaled back in favour of the ground-based missile defense scheme, which lives on to today in the form of ship- or land-launched interceptor missiles that can – when all goes to plan – knock down a ballistic missile in flight. If you are wondering how Brilliant Pebbles got its name, it came from the idea that these would be more intelligent and smaller than a type of guided missiles, then known as “smart rocks”.
Space Based Laser (Cancelled 2002)
Started by the Defense Advanced Research Projects Agency (Darpa) as the Alpha High Energy Laser, and then later transferred to the Strategic Defense Initiative Organization, the Space Based Laser was supposed to lead to a megawatt class laser that could shoot down missiles. Unlike Excalibur, however, the Space Based Laser was to be based on a chemical laser, and thus didn’t require setting off nuclear explosions in space. What ensued, however, was years of cost overruns and schedule delays, as the Pentagon and contractors struggled with the complexity of putting a chemical laser in space with a mirror that could reflect the beam and a tracking system that would allow it to hone in on a missile. Though work on the idea of a Space Based Laser continued for years after the Strategic Defense Initiative was cancelled, by 2002, the director of the Missile Defense Agency announced that it was being shelved. The laser never made it to space.
Airborne Laser (Cancelled 2009)
The notion failed as much because of the plans for how it would be used stretched the imagination of military planners. A fleet of Boeing 747 aircraft equipped with lasers would circle the planet waiting for a possible missile attack. Once such an attack was imminent, the aircraft would swoop in and intercept the missile during its vulnerable “boost phase”. Integrating the laser on the aircraft and demonstrating it could work as promised proved daunting: problems such as atmospheric turbulence, which affects beam propagation, proved difficult to solve. The laser also required dangerous chemicals to operate. After years of development and billions spent, then Defense Secretary Robert Gates cancelled the programme, saying its “proposed operational role is highly questionable.”
Eighth Card (Cancelled late 1960s)
Reportedly named for a reference to a card game trick that would give the United States the upper hand over the Soviet Union, this once top-secret laser programme was based on a gas-dynamic carbon dioxide laser that was supposed to reach 500 kilowatts. Numerous reviews eventually determined that, among other problems, scaling it up in power while maintaining the beam quality would be impractical.
Project Seesaw (Cancelled late 1960s)
In the 1960s, the U.S. government funded the top-secret project, which looked at the feasibility of particle beams for missile defense. Bounced between various agencies, including the Advanced Research Projects Agency (now known as Darpa), the project literally see-sawed between evaluations that deemed it theoretically feasible, or practically impossible. Eventually the latter evaluation won out, and no particle beam was developed.
Project Argus (Cancelled approximately 1959)
In 1958, the United States carried out a series of top-secret nuclear tests meant to test a missile defense theory forwarded by an eccentric physicist at the Lawrence Livermore National Laboratory in California. The concept was that nuclear weapons detonated in the upper atmosphere would create an artificial radiation belt capable of stopping incoming intercontinental ballistic missiles—a sort of atmospheric missile shield. Though the tests were hailed as successful the scheme, at the time dubbed “the greatest scientific experiment ever conducted”, was deemed impractical, if not impossible, for stopping nuclear attacks, and never went beyond testing.