Forty Years Later, the Voyager Spacecraft Remain Beacons of Human Imagination

The sky in Cape Canaveral was a wan blue-gray on the morning of August 20, 1977, and an eerie stillness hung over the warm waters of the Atlantic Ocean. The quiet was broken at 10:29 a.m. local time, when the twin boosters of a Titan III-Centaur launch system roared to life on the launch pad, lifting from Earth’s surface NASA’s Voyager II spacecraft, assembled painstakingly in the clean rooms of California’s Jet Propulsion Laboratory and bound on an interplanetary odyssey of unprecedented proportions.

Voyager II’s primary targets, like those of its twin, Voyager I, were the gas giants Jupiter and Saturn. Since Voyager II’s trajectory was less direct, Voyager I—true to its name—arrived at Jupiter first, despite having departed Earth more than two weeks later than its counterpart, on September 5.

Both equipped with a battery of tools including standard cameras, infrared and ultraviolet imagers, magnetometers and plasma sensors, the Voyager spacecraft arrived at their destination in 1979, nearly two years after they set out. With stunning thoroughness, the two vehicles surveyed Jupiter (including its famous Great Red Spot), Saturn (including its dusty, icy rings), and the pair’s myriad moons, generating numerical data still instrumental today and capturing high-resolution photos of faraway worlds that could previously only be dreamed of.