Jet force is the exhaust from some machine, esp. aircraft, propelling the object itself in the opposite direction as per Newton's Third Law. An understanding of jet force is intrinsic to the launching of drones, satellites, rockets, airplanes and other airborne machines. Jet force is the exhaust from some machine, esp. aircraft, propelling the object itself in the opposite direction as per Newton's Third Law. An understanding of jet force is intrinsic to the launching of drones, satellites, rockets, airplanes and other airborne machines.