The Voyager program consists of two unmanned space probes (Voyager 1 and Voyager 2) that were launched in 1977 to study the planets Jupiter and Saturn. These probes were built by the Jet Propulsion Laboratory and are funded and controlled by NASA. The probes were not only successful in this mission, but have continued their journey to the outer solar system and are still operational today. If you have ever wondered how they are powered and how they have remained running after all of these years, keep reading to find out.
How are the Voyager probes powered?
Both of the Voyager probes are powered by radioisotope thermoelectric generators (RTGs). Basically an RTG is an electrical generator that is powered by radioactive decay. The heat released by the radioactive material is converted into electricity. The RTGs in the Voyager probes are powered by plutonium-238 and each probe had a total of 3 RTGs, which provided a total power of about 470 watts when they were launched.
The plutonium-238 decays over time, it has a half life of 87.84 years, and today the probes have approximately 265 W of power available. As the power output of the RTGs drops some of the operations of the probes must be switched off. It is estimated that the probes will remain operational until about 2025 when they may no longer have the power to support the scientific equipment. If this prediction is accurate this means that the probes will have operated for an impressive 48 years!
Did you know?
Voyager 1 has travelled further from Earth than any other human-made object and will probably become the first such object to leave the solar system.
RTGs are commonly used in space missions, but they have been used other applications such as in unmanned lighthouses and for remote monitoring sites.
You can follow the progress of the NASA Voyager probes on twitter! http://twitter.com/#!/NASAVoyager2