Beijing, May 22 (Reporter: Liu Xia) - According to the website "Nature" on the 21st, the European Space Agency recently announced that the upcoming "Mars Space Biology" mission to Mars will use a groundbreaking nuclear energy source - plutonium. The reactor device is planned to utilize the heat generated from plutonium's radioactive decay to maintain the spacecraft's temperature. This will be the first time a spacecraft uses plutonium for a heating system.
The Mars rover "Rosalind Franklin" (artistic rendering). Image source: European Space Agency
Utilizing devices called Radioisotope Heater Units (RHUs) that generate heat through the decay of radioactive elements. By installing RHUs on spacecraft, reliable and long-lasting heat sources are provided for various components and instruments, keeping them warm in the cold expanse of space. This is particularly crucial for missions operating in extreme cold environments like outer space or other celestial bodies, where traditional heating methods such as electric heaters may not function.
The European Space Agency has traditionally relied on American or Russian partners for RHUs using plutonium-238 radioactive decay. However, since 2009, the agency has been developing plans to manufacture radioisotope heaters and batteries. Osin Satheran, head of the European Space Agency's Mars exploration team, highlighted that these nuclear heating devices enable spacecraft to stay warm in shadowed areas like volcanic vents or during the night, allowing for exploration of broader regions and extending mission lifespans.
The RHU used in this mission is the world's first to utilize americium-241 (a byproduct of plutonium decay) for heating. While the power output per gram of americium-241 is lower than an equivalent mass of plutonium, americium-241 is more abundant and cost-effective. This means that even though RHUs may require more isotopes to operate, their overall cost could be lower.
The production of americium RHUs is part of the "European Device Utilizing Radioisotope Energy (ENDURE)" project. These RHUs will heat components within the lander platform, which will deploy the "Rosalind Franklin" Mars rover onto the Martian surface. The rover is equipped with a 2-meter-long drill that can dig deep into the Martian surface, searching for traces of ancient Martian life.
