“Europe’s upcoming Mars mission will use a pioneering nuclear-powered device that harnesses the radioactive decay of americium to keep its components warm — a first for spacecraft…
ESA’s heater units will not only be a first for Europe, but the first anywhere to use americium-241, a by-product of plutonium decay that packs less power per gram than its predecessor. But americium-241 is more abundant and cheaper, meaning that even if the RHUs require more of the isotope to run, they might be less expensive overall…
The Rosalind Franklin rover is uniquely equipped to search for traces of ancient life on Mars, with a 2-metre drill that allows it to burrow deep beneath the Martian surface.”
From Nature.