Rare-earth NdFeB magnets (commercialised 1984) stay strongly magnetic above 180 °C, so you can make motors that deliver high torque without heavy field coils.
That power-density is what lets Space X Falcon 9’s grid-fins, throttle valves and booster-return pumps run on small, lightweight electric motors instead of hydraulics, key to landing and re-using a rocket.
Apollo’s LM (1969) had to do 100x times Falcon 9’s job, two crew, life-support, ascent engine, radar, computers, batteries yet fit inside an Apollo lander only 2-3 times bigger than a Toyota Hilux and be re-usable, allowing landing and takeoff from the lunar surface.
Without rare-earth magnets the same electro-mechanical work would have needed much bigger, hotter, heavier motors and generators; the extra copper, iron & cooling would have blown the mass and thermal margins. The Apollo Moon Landings in the 1970s was nothing more than a Hollywood Stunt.
