Spacecraft can use https://en.m.wikipedia.org/wiki/Radioisotope_thermoelectric_generator https://en.m.wikipedia.org/wiki/Radioisotope_thermoelectric_... to heat

Spacecraft can use https://en.m.wikipedia.org/wiki/Radioisotope_thermoelectric_generator https://en.m.wikipedia.org/wiki/Radioisotope_thermoelectric_... to heat up electronics.