Spaceborne GPS Receivers

Our relationship with space has changed dramatically since the first words were heard from the Moon in 1969. Space above Earth is now a complex array of more than 2,200 satellites, not including space debris made up of spent rocket boosters, dead satellites and a wrench or two from space walks and repairs. And, more satellites, large and small, are launching all the time.

In 1997, engineers at General Dynamics designed and built a transponder, or radio, that would travel aboard the Cassini spacecraft, the nation’s first full-scale mission to explore Saturn. After reaching Saturn, the Cassini mission was to last only four years. Almost twenty years after launch, the spacecraft crashed into Saturn’s gaseous surface after sending millions of images, and textbooks worth of scientific data to Earth, helping reveal the secrets of Saturn’s rings and moons.

NASA’s twin spacecraft, Voyager I and II are exploring where nothing from earth has ever flown before. The initial goal of the Voyager mission was a 12-year effort to explore Jupiter and Saturn, but due to the success of the spacecraft and a planetary alignment that occurs about every 175 years it has been extended for the last 40 years to explore Uranus and Neptune and even to the outermost edge of the Sun’s domain, and beyond.