differential sail

artist's concept of a differential sail spacecraft

Image credit: Artist's concept of a differential sail spacecraft. Credit: Popular Science.

A differential sail is one of seven types of hypothetical space drives suggested by Marc Millis of the Breakthrough Propulsion Physics Program at NASA's Glenn Research Center (see Millis drives).


The differential sail would work by absorbing cosmic radiation falling on it from one direction and reflecting the incident radiation from the opposite direction. The imbalance in radiation pressure would push the sail ahead.


Compare with diode sail and induction sail.