Radio Thermoelectric Generators

July 19, 2023

According to sources, ISRO and Bhabha Atomic Research Center (BARC) are developing Radio thermoelectric generators (RTGs).
RTGs are lightweight, compact spacecraft power systems.
The RTGs use radioactive materials, such as Plutonium-238 or Strontium-90, which release heat as they decay.
It contains two parts-
- the radioisotope heater unit (RHU) which generates heat, and
- the RTG, which converts the heat into electricity.
Large difference in temperature between this hot fuel and cold environment of space is applied across thermocouples, which generates an electrical current using no moving parts.
- Thermocouple is a material that develops a voltage if there is a heat gradient across it.
RTGs are independent of solar proximity and planetary alignment which are necessary to send a spacecraft deep into space, such as into inter-planetary missions.
Earlier, spacecrafts such as Voyager, Cassini etc have been powered by RTGs.