how have scientists used nuclear power as a fuel for spacecraft
Nuclear power in space
short
either small fission systems or radioactive decay for electricity or heat
Nuclear power in space is the use of nuclear power in outer space , typically either small fission systems or radioactive decay for electricity or heat . Another use is for scientific observation , as in a Mössbauer spectrometer . One common type is a radioisotope thermoelectric generator , which has been used on many space probes and on manned lunar missions , and another is small fission reactors for Earth observation satellites such as the TOPAZ nuclear reactor . A radioisotope heater unit provides heat from radioactive decay of a material and can potentially produce heat for decades .