The StarLink satellites use krypton thrusters instead of xenon [0]. They need more electic power to run, but produce higher specific impulse [1]. And krypton is

The StarLink satellites use krypton thrusters instead of xenon [0]. They need more electic power to run, but produce higher specific impulse [1]. And krypton is cheap. [0] https://www.spacex.com/sites/spacex/files/starlink_press_kit.pdf https://www.spacex.com/sites/spacex/files/starlink_press_kit... [1] http://ngpdlab.engin.umich.edu/electric-propulsion/krypton-HET http://ngpdlab.engin.umich.edu/electric-propulsion/krypton-H...