Electrospray thrusters
Extremely fine-thrust engines that spray charged droplets to hold a spacecraft steady with great precision. Busek's units flew on ESA's LISA Pathfinder, which tested technology for detecting gravitational waves from space.
Why it matters
Some science missions need a spacecraft to stay almost perfectly still or fly in precise formation, far beyond what normal thrusters can manage. Electrospray thrusters make that possible, which future space observatories depend on.
How the technology works
A strong electric field pulls charged droplets or ions from a liquid propellant at the tip of tiny emitters, producing a very small and finely adjustable thrust. Because the thrust can be set in tiny steps, it can cancel out the faint push of sunlight and other disturbances on a spacecraft.
Sources
Updated Oct 22, 2026 · How we source facts · Suggest a correction