A NASA spacecraft bound for an unexplored metal-rich asteroid has reignited its plasma thrusters, continuing its cruise deeper into the Solar System after switching to a backup fuel line.
The $1.4 billion Psyche mission, built to explore an asteroid with the same name, has four electric thrusters fueled by xenon gas. Psyche’s solar electric propulsion system is more fuel efficient than conventional rocket thrusters, and it works by flowing xenon through an electromagnetic field, which ionizes the gas and expelling the ions at high speed to produce thrust.
The plasma engines generate lower thrust than chemical rocket engines, but they can accumulate years of run time over the course of a mission, enabling a spacecraft to make significant changes in its velocity to steer its way through space.