Futurist, scientist and author Arthur C. Clarke, who described the perfect orbit for communications satellites in a paper published in October 1945, died March 17 at his home in Colombo, Sri Lanka.

At the time, the concept of communication satellites was considered by many prominent scientists to be an impossible vision, but in October 1957 the Russians orbited Sputnik, and the United States followed in January 1958 with Explorer 1. The first commercial communications satellite, Early Bird, was launched in 1965 into precisely the orbit that Clarke had described two decades earlier, and today, hundreds of satellites provide various services around the globe.

In the 1940s, Clarke was one of the pioneers of ground approach radar, which today is a fundamental element of air traffic safety, and in the 1950s, he worked with Jacques Cousteau and others to help perfect scuba equipment. Clarke also had written about topics such as geothermal, solar and wind energy; the search for extra-terrestrial life; the development of the space elevator concept; and dozens of other innovative ideas.