Savannah River Site-powered Voyager probes mark 45 years in space

Matthew Christian, Aiken Standard, S.C.
·2 min read

Sep. 13—Two space probes powered by plutonium produced at the Savannah River Site recently marked 45 years in space.

Voyager 2 was launched on Aug. 20, 1977 and its twin probe, Voyager 1, was launched on Sept. 5, 1977.

In the 1970s, an intern, Gary Flandro, at NASA's Jet Propulsion Laboratory, realized that the four gas giants — Jupiter, Saturn, Uranus and Venus — would be in an alignment that would allow for easier exploration.

Eventually, the two voyager probes were developed to take advantage of the opportunity for exploration. Voyager 2 was launched first to explore Uranus and Venus and Voyager 1 was to explore Jupiter and Saturn.

Both probes use radioisotope thermoelectric generators — devices that use heat from the decay of radioactive elements to generate electricity — that are powered by plutonium 238 produced at SRS.

Voyager 1 passed Voyager 2 in late 1977. On March 5, 1979, it reached its closed approach of Jupiter. The probe located the first active volcanos outside of Earth on Io, the first lightning outside of Earth on Jupiter, helped determine that the Great Red Spot was a giant storm, found the Jovian ring system and two new moons.

On Nov. 9, 1980, Voyager 1 made its closest approach to Saturn. It found three new moons and determined that Titan had a nitrogen rich atmosphere, the first such atmosphere found besides Earth. Also in 1980, it took the Pale Blue Dot picture.

It then began moving out of the Solar System. It crossed into interstellar space in 2012.

Voyager 2 made its closest approach to Jupiter on July 9, 1979. It found another moon and its pictures of Europa suggested evidence of an underwater ocean. On Aug. 25, 1981, it made its closest approach to Saturn.

The probe made its closest approach of Uranus in 1986, in the process finding 11 new moons and determining that the planet is the coldest in the Solar System. It made its closest approach of Neptune in 1989 finding six new moons and the Great Dark Spot. It then began moving out of the Solar System.

It crossed into the interstellar medium in 2018.

NASA expects Voyager 1 to be able to operate at least one instrument until 2025. Voyager 1 will be out of range of the Deep Space Network in 2036.

Voyager 2 is expected to keep transmitting until the mid-2020s.