by Nicole Quenelle
NASA’s Armstrong Flight Research Center

Rocket off course? It could be a slosh problem.

Propellant slosh, to be exact. The motion of propellant inside a rocket-based launch vehicle or spacecraft tank is an ever-present, vexing problem for spaceflight. Not only can it make gauging the amount of available propellant difficult, but the volatile waves of liquid can literally throw a rocket off its trajectory.