Xenon, ion propulsion

Xenon, propellant of the plasma thrusters of geostationary satellites and deep-space probes, is only a tiny by-product of the air-separation units of large metallurgical complexes. Ukraine and Russia supplied a large share before the war; its scarcity pushed SpaceX to switch Starlink to krypton and then argon. Every surge in satellite construction tightens a structurally narrow market.