Space exploration is undoubtedly an activity that characterizes our species and determines our future. We dream of conquering other worlds beyond our own and inhabiting Mars, the Moon, and other planetary systems. The main problem is distance. Everything in the universe is very far from us, and with our current technology, a trip to any world outside the Solar System in less than a millennium is unthinkable. But the brightest minds manage to come up with innovative ideas that could solve our disturbing inability to migrate to other planets. For example, a researcher has proposed using magnetic plasma to propel rockets with 10 times the power of regular boosters.
How we launch stuff into space
Currently, it takes us between six to eight months to reach Mars and between one and 10 years to get to the most remote regions of the Solar System. If we wanted to send a crewed ship of any considerable size to Alpha Centauri, the closest star system to us (4.3 light years), it would take centuries with current propulsion systems.
An ordinary spacecraft that take off from Cape Canaveral several times a year contains a payload (the probe, satellite, ship, or module) that represents one-third of the total weight of the spacecraft and propulsion made up of a nucleus and typically two rockets. The fuel that generates the ignition and continuously the thrust energy that lifts the ship can be solid or liquid. These types of engines are called chemical propulsion. There are also nuclear fusion propellants, which are not used for takeoff but for acceleration during flight.
The problem with chemical engines is that the fuel is effective in getting an initial thrust of propulsion, but for a brief period. Fatima Ebrahimi, a physicist at the Princeton Plasma Physics Laboratory (PPPL), found a way around this problem: using magnetic plasma. She proposes an engine that could generate thrust longer than chemical fuels, allowing the ship to reach speeds ten times faster than the current ones.
Magnetic plasma thruster
Plasma thrusters have been around for decades, but they use electric fields to regulate the activity of the plasma. Instead, Ebrahimi suggests using magnetic fields to take advantage of a phenomenon known as magnetic reconnection.
This phenomenon occurs when two magnetic field lines with opposite charges come closer and connect at a point, canceling their total charge. “At that point of contact, the magnetic energy is annihilated, and the energy is converted into kinetic energy. […] The magnetic reconnection process occurs during the eruption of solar flares when mass and energy are ejected from the solar surface into space,” the researcher told Freethink.
Fatima works in a plasma laboratory where they use magnetic methods to control the plasma in nuclear fusion interventions. In her preprint, Ebrahimi describes the design of a magnetic plasma motor and includes the simulations she did. Magnetic field bubbles produce a tremendous amount of kinetic energy when they form, so this energy could be harnessed to propel spacecraft.
The advantage of having a thruster made up of electromagnets is that you can choose the intensity of the magnetic flux of the plasma, so it would serve as a kind of accelerator that would allow mission engineers to decide the speed and acceleration of their ships at each point of its trajectory.
Making interstellar space exploration possible
“If we make thrusters based on magnetic reconnection, we could possibly complete long-distance missions in a shorter period of time,” she added.
She and her collaborators need funding to take this idea beyond simulations. She hopes to be able to work in a lab in the next few years and one day see her idea embodied in a rocket soaring across the gigantic sky.
Meanwhile, other alternative propulsion projects are still in development. For example, the Direct Fusion Drive (DFD) is a fusion engine whose developers intended to effect takeoff propulsion. They consider it feasible to launch tests with this technology by 2028.