Circa 1990 to current o.o

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The Woodward effect, also referred to as a Mach effect, is part of a hypothesis proposed by James F. Woodward in 1990.^[1] The hypothesis states that transient mass fluctuations arise in any object that absorbs internal energy while undergoing a proper acceleration. Harnessing this effect could generate a reactionless thrust, which Woodward and others claim to measure in various experiments.^[2][3]

Hypothetically, the Woodward effect would allow for field propulsion spacecraft engines that would not have to expel matter. Such a proposed engine is sometimes called a Mach effect thruster (MET) or a Mach Effect Gravitation al Assist (MEGA) drive.^[4][5] So far, experimental results have not strongly supported this hypothesis,^[6] but experimental research on this effect, and its potential applications, continues.^[7]

The Space Studies Institute was selected as part of NASA’s Innovative Advanced Concepts program as a Phase I proposal in April 2017 for Mach Effect research.^{[8][9][10][11]} The year after, NASA awarded a NIAC Phase II grant to the SSI to further develop these propellantless thrusters.^[12][13].