Celebrating 40 years since Voyager 2

Satellite telecommunications company Frequency Electronics (FEI) is celebrating the launch of the Voyager 2 spacecraft by NASA on 20 August 1977 — 40 years ago this week.

The spacecraft has spent the past four decades hurtling through space and is currently situated around 17 billion kilometres from Earth. Yet its precision timing system, designed and manufactured by FEI, is still keeping time, enabling NASA to communicate with the spacecraft, while its sensitive electronics continue to gather information about our universe.

“Forty-four years ago, NASA approached FEI for state-of-the-art master timing clocks for the Voyager satellites,” said Joel Girsky, chairman of the board of Frequency Electronics. “Little did FEI know that they would be the heart of the longest operating and farthest reaching man-made objects in our solar system.”

Voyager 2 and its twin, Voyager 1, are both equipped with long-lasting power supplies, as well as redundant systems that allow the spacecraft to switch to backup systems autonomously when necessary. Each Voyager carries three radioisotope thermoelectric generators, devices that use the heat energy generated from the decay of plutonium-238 — only half of which will be gone after 88 years.

Because the Voyagers’ power decreases by four watts per year, engineers are learning how to operate the spacecraft under ever tighter power constraints. To maximise the Voyagers’ life spans, they also have to consult documents written decades earlier describing commands and software, in addition to the expertise of former Voyager engineers.

Team members estimate they will have to turn off the last science instrument by 2030. However, even after the spacecraft go silent, they’ll continue on their trajectories at their present speed of more than 48,280 km/h, completing an orbit within the Milky Way every 225 million years.

Image caption: An artist concept depicting one of the twin Voyager spacecraft. Image credit: NASA.