The push to electrify transportation has gained immense traction in recent years. Automakers around the world are scrambling to bring out more electric vehicles to market to meet the increasing demand from climate-conscious consumers. Most automakers have also pledged to outright replace their current line-up of vehicles with internal combustion engines (ICE) with fully electric “green” vehicles within the next decade.
At the same time, the pace of the new “space race” is increasing, with private companies racing to achieve new milestones. With the successful launch of SpaceX’s inspiration4 mission, space tourism has been given a boost. Within the next year, at least three different crewed missions with private citizens have been planned.
Yet, spacecraft have been increasingly reliant on liquid hydrogen and methane for fuel. The latter being a potent greenhouse gas, 300 times more efficient at trapping heat compared to carbon dioxide.
Once the stuff of science fiction, efforts to develop a viable propulsion system using the sun’s energy have been successful, although largely used on spacecraft in outer space.
Over the years, a dozen spacecraft from NASA, JAXA, ISRO, and ESA have used solar electric propulsion on a variety of missions.
The latest, and most ambitious project to use the novel technology is NASA’s Psyche spacecraft.
According to a NASA blog post, the mission is scheduled to launch sometime in August 2022. The spacecraft is destined to a distant asteroid known as Psyche, some 2.4 billion kilometers away between the orbits of Mars and Jupiter, and rich in metal.
NASA’s Psyche spacecraft in July 2021 at JPL. Credit: NASA/JPL-Caltech
Although the spacecraft will use the chemical engines of SpaceX’s falcon heavy rocket to escape the Earth’s gravity, once in outer space, it will rely entirely on solar electric propulsion. The spacecraft’s four thrusters, known as Hall thrusters will be powered by electricity generated from the solar arrays.
Xenon, a neutral gas used in plasma TVs, will be used as a propellant. Using electromagnetic fields, the Hall thrusters will accelerate and expel Xenon ions (charged atoms), to create a gentle thrust.
Yet, due to the lack of drag in outer space, the spacecraft can achieve speeds of over 320,000 kilometers per hour. According to NASA, the Hall thrusters on Psyche are so efficient that they can operate continuously for over five years with just 922 kilograms of xenon.
Cover Photo: Credit: NASA/JPL-Caltech