In April of 1961, the cosmonaut Yuri Gagarin became the first human being to travel in space. Eight years later, Neil Armstrong became the first person to set foot on the Moon. Now, companies across the globe, such as SpaceX, race to get the first humans to Mars. This goal is only one in a journey of which we cannot yet - if we ever will - see the end. Still, there are many obstacles ahead of us. One of those obstacles is the means of transportation to be used if we wish to take humans farther than our moon. A trip to Mars with our current technology would take six months to make the journey one way, and six more to make the journey back. While this time frame is somewhat plausible...what if we want to go farther? An answer could be close.
20 years ago, the idea of producing thrust using electromagnetic radiation, the same thing as light, was proposed by a British scientist named Robert Shawyer. 18 years later, in 2014, reports emerged that ‘anomalous thrust’ had been produced using the very same electromagnetic waves. Anomalous thrust means that thrust had been produced, but the reason for its production is unknown even by those who produced it. These reports were met with much skepticism among the scientific community; however, as you may know, in 2016, the National Aeronautics and Space Administration published a study stating that scientists at their Johnson Space Center had produced 1.2 micronewtons per kilowatt (a common unit of measuring thrust) of thrust in a near vacuum, yet again by using electromagnetic radiation. This time, the scientific community paid more attention.
1.2 micronewtons per kilowatts of thrust is actually surprisingly miniscule; popular Hall thrusters normally produce a thrust of 60 millinewtons/kilowatt, which is an entire order of magnitude (ten times) larger than what the EM (Electromagnetic) drive produced. And still, the energy required to produce that tiny amount of thrust with the drive is more than impressive. So, if the drive is (so far) so inefficient, why has it become so popular?
Remember Isaac Newton and his three laws of motion? Well, it seems like this electromagnetic drive doesn’t, because so far, it defies them. The drive is composed of a closed-off, cone-shaped chamber. Inside, microwave radiation (a kind of electromagnetic radiation with a wavelength longer than any visible light) is bounced around, and because the chamber is closed, none of it escapes. Usually, to produce thrust, a propellant is required; the propellant is expelled in the direction opposite of the desired direction. This works, consistently, because of Newton’s third law of motion, which states that for every action, there is an equal and opposite reaction. The action is the propellant being shot backwards; the opposite reaction is the vehicle being propelled forward. However, in the EM drive, no propellant is released; this means that there is no identified action. Yet in various experiments, including NASA’s, it seems there has been a consistent reaction: thrust.
This alone makes the EM drive a possibly magnificent discovery - if it truly works - but it is also revolutionary for space travel. Traditional spacecraft must carry actual tons of propellant to produce the amount of thrust required for their journey, but with this drive, no propellant would be needed. This means that the net weight of spacecraft using the EM drive would be significantly reduced. If functional, it is thought that the EM drive would allow a spacecraft to be sent to Mars in 70 days. Still, we shouldn’t get ahead of ourselves. The NASA experiment acknowledged nine different sources of possible error in their calculations, including vibrations, air currents, magnetic interaction, thermal expansion, and more. All of these things could have been the cause for the “thrust” that was measured, which would mean that the EM drive does not, in fact, work. It is not seldom that laws are said to have been broken, and then proven to be true yet again when it is realized that the original experiment and/or data was flawed. Somewhat recently, in 2011, scientists of the Oscillation Project with Emulsion-Tracking Apparatus (OPERA) thought they had discovered neutrinos (elementary particles, the same kind of thing as protons and electrons) that traveled faster than the speed of light, something previously thought to be impossible. Not surprisingly, it was later confirmed that the data was flawed and neutrinos could not, in fact, break one of the most basic laws of general relativity, which states that nothing can travel faster than the speed of light. Regarding the EM drive’s authenticity, all I can say is, don’t hold your breath.
There is still hope, however. Today, further research continues. NASA has established an Advanced Propulsion Physics Research laboratory, informally known as “Eagleworks,” to understand how this drive works and investigate its possible uses to assist the exploration of our universe. There are also many independent companies researching the anomaly for themselves; for example, the Satellite Propulsion Research Ltd, a small company based in the UK. Sooner or later, we will figure out whether this is one of the biggest discoveries since gravity, or just another case of flawed data.