propellant

Then they backed the membrane with a gel matrix containing a perfluorocarbon (PFC) propellant and fluorescent "nanobullets" about a micron wide, and hit it with ultrasound.

Today’s spacecraft use rockets and rockets use large quantities of propellant.

As propellant blasts out of the rocket in one direction, it pushes the spacecraft in the other.

In-space electric propulsion can reduce the amount of fuel, or propellant, needed by up to 90% compared to chemical propulsion systems.