impellori

Impellori are a class of propulsion devices described in science fiction and speculative technology as mechanisms that produce thrust without conventional propellant. In many treatments they achieve motion by interacting with fields or energies that remain attached to the vehicle, or by tapping external energy sources, rather than ejecting material mass. As a result, impellori are typically framed as reactionless or near-reactionless drives, though authors differ on what constitutes a violation of momentum conservation.

Theoretical models vary. Gravitic impellori propose manipulation of local gravitational fields to push the ship along a desired vector. Electromagnetic impellori rely on high-intensity field interactions to generate thrust, often using internal media within a reaction chamber. Quantum vacuum impellori claim to extract and direct energy from the vacuum or zero-point fields. Hybrid designs combine elements from several models. Realistic depictions usually require substantial power sources, such as fusion reactors, antimatter, or large-scale energy harnessing.

Performance and feasibility are highly fictional and depend on the author’s rules. Common considerations include thrust-to-power ratios, efficiency limits, and thermal management. Many depictions warn of technical hazards such as field leakage, interference with onboard systems, or instability during rapid maneuvers. Impellori are frequently portrayed as enabling rapid interstellar travel, agile maneuvering in space, or propulsion without the logistical burden of propellant.

Etymology: the term derives from the Latin impellere, meaning to drive or push. See also reactionless drive, zero-point energy, and related warp concepts.