Answer: GPS

In 1983, Korean Airlines Flight 007 accidentally strayed into prohibited air space over the USSR. Russian interceptor jets scrambled to meet the civilian aircraft. Despite identifying the plane as a civilian craft in the wrong airspace, the fighter pilots shot the plane down—all 269 people aboard the passenger jet were killed. This was the second time Russian fighter jets had fired on a Korean airliner that was in their airspace (both times as a result of poor navigation tools and problems).

In response to the tragedy, U.S. President Ronald Reagan issued a directive that the Global Positioning System—then under development by the military—would be available for the public to use as a tool for the betterment of mankind and to prevent future tragedies caused by outdated navigation techniques.

When the system became fully operational in 1995, it included provisions for both military and civilian use. Restrictions on the accuracy of civilian GPS readings were maintained until relaxed by a policy directive from President Bill Clinton in 1996—the order became effective May 2, 2000, and ever since then, both civilian and military GPS units have had access to the same high-quality signals and information.