How does radioisotope thermoelectric generator work?

A radioisotope thermoelectric generator, or RTG, uses the fact that radioactive materials (such as plutonium) generate heat as they decay into non-radioactive materials. The heat used is converted into electricity by an array of thermocouples which then power the spacecraft.

How does an RTG generator work?

How Does an RTG Work? RTGs work by converting thermal energy into electrical energy through devices known as thermocouples. The natural decay of plutonium-238 produces heat that is then transferred to one side of the thermocouple.

How does a thermoelectric work?

Thermoelectric coolers operate according to the Peltier effect. The effect creates a temperature difference by transferring heat between two electrical junctions. When the current flows through the junctions of the two conductors, heat is removed at one junction and cooling occurs.

How long can an RTG last?

14 years
Currently, a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG, the RTG on the Curiosity rover) weighs 35.5 kilograms and has a life expectancy of 14 years.

What is radioisotope used for in medicine?

Radioisotopes are an essential part of medical diagnostic procedures. In combination with imaging devices which register the gamma rays emitted from within, they can be used for imaging to study the dynamic processes taking place in various parts of the body.

What are the advantages of radioisotope thermoelectric generator?

Ability to produce high energy radiation. Tendency to produce radiation decay heat. Possession of long half-life for continuous energy production. Large heat power-to-mass (or density) ratio.

What isotope is used in RTG?

Plutonium-238
Based on all of the above factors, the most frequently used isotopes for RTG fuels include Plutonium-238 (Pu-238), Strontium-90 (Sr-90), and Curium-244 (Cm-244) with Pu-238 being the most cited fuel on most resources about RTGs.

Where are RTGs used?

RTGs have been used as power sources in satellites, space probes, and uncrewed remote facilities such as a series of lighthouses built by the Soviet Union inside the Arctic Circle.

What are thermoelectric made of?

Three materials are commonly used for thermoelectric generators. These materials are bismuth (Bi2Te3) telluride, lead telluride (PbTe) and Silicon germanium (SiGe). Which material is used depends on the characteristics of the heat source, cold sink and the design of the thermoelectric generator.

What are thermoelectric devices?

A thermoelectric generator (TEG), also called a Seebeck generator, is a solid state device that converts heat flux (temperature differences) directly into electrical energy through a phenomenon called the Seebeck effect(a form of thermoelectric effect).

How hot is an RTG?

The initial thermoelectric couple hot junction temperature was 1273 K (1000 °C, 1832 °F) with a cold junction temperature of 573 K (300 °C, 572 °F). Each Voyager spacecraft has 3 RTGs. Collectively, the RTGs supplied each Voyager spacecraft with 470 watts at launch.

How much does an RTG cost?

As noted below, the cost estimated General Purpose Heat Source (GPHS) RTG costs range from $65M-$90M, depending on the exact delivery option. For these studies, the cost of the GPHS RTG was taken as $65M.