Radio Thermoelectric Generators (RTGS)

Recently, the Bhabha Atomic Research Centre (BARC) and the Indian Space Research Organisation (ISRO) began working together to develop radio thermoelectric generators (RTGs), a novel strategy intended to overcome the limitations of conventional
chemical engines for interplanetary travel.

How Does RTGS Work?

• Chemical engines are effective for satellite thrusters, but due to fuel constraints and a lack of solar power in far-off places, they are unsuitable for long space flights.
• RTGS are innovative power sources designed to address these challenges in deep space missions.
• They utilize radioactive materials, such as Plutonium-238 or Strontium-90, which emit heat as they decay over time.
• The propulsion and power of spacecraft are made possible by the harnessing and conversion of this heat into electricity.
• Essentially, the engine contains two parts-
  1. The Radioisotope Heater Unit (RHU):
     • Heat is produced by the RHU as a result of radioactive material decay.
     • It starts the procedure by releasing thermal energy, which forms the basis for the production of electricity.
  2. The RTG (Heat-to-Electricity Conversion):
     • The RTG part converts the heat that the RHU produces into useful power.
     • A thermocouple, a substance that produces electricity when exposed to a temperature gradient, is used for this conversion.
     • The spacecraft’s batteries are charged using the voltage the thermocouple produces.
     • The propulsion systems that are powered by these batteries, in turn, enable interplanetary flight.