How rockets reignite in zero gravity

Transcript

To restart, a rocket engine must first solve the problem of its fuel, which floats aimlessly in zero gravity. Small thrusters fire briefly, creating a gentle push that settles the propellants at the bottom of their tanks, ready for the main engine. With the fuel in place, an ignition system provides the spark. Some engines use hypergolic propellants, which ignite spontaneously on contact, eliminating the need for a separate igniter altogether.