If we want to travel to interstellar space one day, engines that use electrodeless plasma thrusters could be the key.

If we want to explore the solar system in the coming decades, we need better technology. By that, I mean propulsion systems primarily. The stuff we have right now just doesn’t cut it if we want to go beyond Mars. Given the current technology, even traveling to the red planet takes several months. And this makes exploring the solar system a difficult task ahead. And by that, I mean exploring it with manned crews. Luckily, scientists are already coming up with novel and innovative ways to help us travel to the “stars.” Imagine having technology that, instead of taking you to Mars in months, can take you there in weeks or even days. Even though it may sound like science fiction, scientists are working hard to turn it into pure science.

High-power electrodeless plasma thruster

In recent reports from Tohoku University, a researcher has improved a high-power electrodeless plasma thruster. This paves the way toward deep space exploration. Spacecraft use electric propulsion to propel themselves by accelerating their propellers with electromagnetic fields. The use of electric propulsion devices, such as cross-linked ion thrusters and Hall thrusters, has already been successfully demonstrated on several space missions. The propellant, or plasma, is ionized by solar energy. It is then accelerated by electromagnetic fields to generate thrust energy. Due to their high power level, these devices have a limited useful life due to the electrodes getting exposed to plasma and becoming damaged. So, scientists looked for an alternative. Eventually, they thought, why not get rid of electrodes? The ta-daaa moment.

Electrodeless plasma thrusters

Scientists have developed electrodeless plasma thrusters to overcome this problem. In one example, radio frequency (rf) is used to generate plasma. To create thrust, radio waves are directed to a cylindrical chamber. There, they are converted into plasma by a magnetic nozzle. There are several advantages to using these MN rf plasma thrusters, also known as helicone thrusters, such as their simplicity, operability, and potential high power-to-thrust ratio. Despite this, the efficiency with which radio frequency power is converted into thrust energy has hindered its development. A modest conversion rate of 20% has been achieved in more recent studies after early experiments generated conversion rates in the single digits.

An efficiency of 30%

Professor Kazunori Takahashi from Tohoku University’s Department of Electrical Engineering reported an efficiency of 30% in a recent study published in Scientific Reports. Although mature electric propulsion devices usually require xenon gas, which is hard to come by in sufficient quantities, the current efficiency of 30% could be achieved using argon propellant. Accordingly, an MN rf plasma thruster could save the Earth’s resources and reduce its cost. As a result of the breakthrough, high-powered space transportation technology is a step towards becoming more efficient and widely accessible.