[Reading Science] "This Is the Heart of Future Nuclear-Powered Spaceships"

Rolls-Royce UK Unveils Concept Design for Micro Modular Reactor

[Asia Economy Reporter Kim Bong-su] "This is the heart of the nuclear propulsion spacecraft that will lead future space exploration."

Recently, as major space development countries including the United States are developing nuclear propulsion engines for deep space exploration such as Mars, the global engine development company Rolls-Royce has attracted attention by unveiling a conceptual design of a micro nuclear reactor for spacecraft engines.

The company posted this information along with photos on its official Twitter account on the 27th of last month. It explained, "(The small reactor) is essentially designed to use a safe and very robust fuel system," adding, "Individual uranium particles are encased in multiple protective layers that act as a control system, enabling them to withstand extreme conditions." Rolls-Royce has been developing micro nuclear reactors for spacecraft engines in cooperation with the UK Space Agency (UKSA) since 2021.

A micro nuclear reactor for spacecraft being developed by Rolls-Royce in the UK. Photo by Rolls-Royce Twitter account.

The method of generating electricity using nuclear materials for use in space is broadly divided into two types: nuclear batteries and micro nuclear reactors. Nuclear batteries convert heat generated during nuclear decay into electricity using motors and thermoelectric devices. There is also a method that produces electricity by colliding beta particles with semiconductors. NASA has already demonstrated this several times for deep space exploration. The Voyager 1 and 2 probes, which explore beyond the solar system, and the Mars exploration rovers Perseverance and Curiosity each used nuclear batteries. However, micro nuclear reactors have not yet been used in practice. The UK Space Agency (UKSA) and Rolls-Royce have been developing them since 2021, and NASA announced on the 24th of last month that it will develop a small reactor for nuclear propulsion engines by 2027 in collaboration with the Defense Advanced Research Projects Agency (DARPA) under the U.S. Department of Defense.

South Korea also succeeded in space demonstration by using a radioactive isotope thermoelectric generator (RTG) made of Plutonium-238 (half-life 88 years) developed by the Korea Atomic Energy Research Institute during the second launch of the Nuri rocket in June last year to supply power to a performance verification satellite. Although it is an ultra-low power of 120mW, it is enough to be used for satellite measurement sensors for 40 years. The Korea Atomic Energy Research Institute plans to scale up to 6W or more in the future and intends to use it for lunar landers and other applications by 2031.