A former NASA engineer working on a propellant-less propulsion drive has claimed that the device can deliver enough thrust to achieve lift in Earth’s gravity, an effect which should not take place under our current understanding of physics.
Dr Charles Buhler, who worked on a range of programs while at NASA, has since co-founded Exodus Propulsion Technologies, which in 2019 applied for a patent for a system that they claim can generate force using asymmetrical electrostatic pressure. According to the patent, the system generates a voltage difference across an electrically conductive surface.
“The applied voltage difference creates an electric field resulting in an electrostatic pressure force acting on at least one surface of an object. Asymmetries in the resulting electrostatic pressure force vectors result in a net resulting electrostatic pressure force acting on the object,” the , adding that the invention could be used as a thruster to propel spacecraft. “The magnitude of the net resulting electrostatic pressure force is a function of the geometry of the electrically conductive surfaces, the applied voltage, and the dielectric constant of any material present in the gap between electrodes.”
Buhler explained the device to the Applied Power Electronics Conference.
According to Buhler, whose team has been looking for alternative explanations for the force generated, they were able to create a large enough force for the (very small) object to overcome Earth’s 1G of gravity (i.e. enough thrust to move the object off the ground in Earth’s gravity) using the method.
That may sound like peanuts – but in the near-vacuum of space, you do not need a lot of thrust to accelerate (depending, of course, on the mass of your payload). If you could maintain a constant 1G of acceleration, for example, not only could you enjoy a nice artificial gravity equivalent to that on Earth, but you could reach within a human lifespan (or at least, from the traveler’s perspective). But doing so would require an unimaginable amount of force beyond what we are capable of delivering with current propellants.
Buhler’s claim, were it to be proven true and not the result of another force the team has not accounted for, would be huge. During tests, the team claims to have found an even more puzzling result; the device was apparently sometimes able to maintain this thrust without a constant electrical input.
“The most important message to convey to the public is that a major discovery occurred,” Buhler told . “This discovery of a New Force is fundamental in that electric fields alone can generate a sustainable force onto an object and allow center-of-mass translation of said object without expelling mass.”
There are plenty of reasons to be skeptical of such claims. Other devices, notably the , have been claimed to have produced thrust without propellant. This was a highly controversial claim, as to contravene the law of conservation of momentum, and every action having an equal and opposite reaction. Later teams trying to replicate the mysterious thrust created by the EmDrive found that it could all be explained with and a thermal effect.
“With the aid of a new measuring scale structure and different suspension points of the same engine, we were able to reproduce apparent thrust forces similar to those measured by the NASA-team, but also to make them disappear by means of a point suspension,” Professor Martin Tajmar explained to German website .
“When power flows into the EmDrive, the engine warms up. This also causes the fastening elements on the scale to warp, causing the scale to move to a new zero point. We were able to prevent that in an improved structure. Our measurements refute all EmDrive claims by at least 3 orders of magnitude.”
If the force behind Exodus Propulsion Technologies’ design was proved to be the result of asymmetrical electrostatic pressure and not some other unaccounted-for force, and it can be shown to work on larger scales, it would be revolutionary to spaceflight.
“There are rules that include conservation of energy, but if done correctly, one can generate forces unlike anything humankind has done before,” Buhler added. “It will be this force that we will use to propel objects for the next 1,000 years… until the next thing comes.”
But it is, as they say, an extraordinary claim requiring extraordinary evidence. Buhler is inviting other scientists to look at the results and try to understand the underlying physics behind it. It could be that Buhler, or another, will find normal physics is behind the apparent propellent-less thrust.
For now, we would caution not to get your hopes up space high.