In Star Wars, the spacecraft of the galaxy far, far away are propelled through space by massive engines glowing bright blue. Current spacecraft may pale in comparison, but the technology that powers these ships is becoming a reality.
Other countries like China have devoted significant resources toward developing space capabilities. That’s why ensuring that the United States is leading in rocket technology is important to allow U.S. spacecraft to respond quickly to changes in low-Earth orbit and deeper in space. Developing different rocket technologies and fuel variety can equip the United States with a plethora of options for maintaining low-orbit spacecraft, traveling to Mars, and harvesting resources from space for transportation back to Earth in an economical time frame.
Innovations in rocket propulsion using several different types of designs can allow future spacecraft to reverse course, turn around, change directions mid-flight, and reach their destinations in a matter of months. Plasma rocket technology will be the key building block for long-distance space travel. The federal government should continue to champion this technology’s development for further utilization of space resources and defense applications.
Plasma-based systems work by heating ions of fuel to create plasma and then directing that plasma using magnetic fields to be dispensed in a particular direction. This creates thrust to propel a craft forward, but plasma-based engines can vary plasma output and direction, creating much more potential for navigating the vacuum of space.
Ad Astra’s Variable Specific Impulse Magnetoplasma Rocket (VASIMR), for example, can vary thrust power and can take either hydrogen, helium, or deuterium as fuel. This variety of fuel types would allow for extreme flexibility in space, as electrolysis would split water into usable oxygen and hydrogen for human consumption and fuel for the plasma rockets. As hydrogen is also one of the best shields against harmful radiation, its use as fuel for plasma rockets would reduce the likelihood of astronauts or sensitive machinery being damaged by space radiation and any potential radiation given off by the engines themselves.
Plasma-based rockets have the potential to radically decrease travel times in outer space and in low-Earth orbit. Most rockets today are designed around chemical use, which caps their exhaust velocity around 5,000 meters per second. While that may seem fast, this causes multi-ton rockets to carry thousands of gallons of fuel to deliver a small payload to a distant planet. Capping exit velocity also leads to journeys that would take months, even years, to complete one-way.
Using plasma-based rocket technology, like the Pulsed Plasma Rocket (PPR) developed by NASA and Hbar Technologies, has the potential to cut humans’ travel time to Mars down to only two months. Current investigations into PPR technology have shown that this type of engine may be capable of generating 20,000 pounds of force (lbsf). This force generation runs against the need for constant electron bombardment within the engine to produce plasma, meaning a consistent source of electricity is needed.
While some fuels may fill niches during a space flight in order to preserve fuel consumption or reduce a spacecraft’s weight, ion and nuclear fission rocket technologies all are viable substitutes for plasma-based rockets. Today, ion thrusters are used to adjust satellites’ position in Earth’s orbit and are the main fuel source for probes on multi-year journeys into the solar system. Ion fuel systems have been recorded as having up to 90 percent fuel efficiency and can travel massive distances on a relatively small amount of fuel.
Case in point, NASA’s Evolutionary Xenon Thruster has been operated for over 43,000 hours on 770 kilograms of xenon propellant as fuel. The drawback for fuel efficiency is that spacecraft using ion thrusters require a large amount of time to reach full acceleration. Small probes and satellites powered by ion thrusters can reach speeds of up to 200,000 mph but require multiple months to reach top speeds.
Ion thrusters have the potential to power smaller spacecraft or act as a backup power source but have yet to be utilized for larger spacecraft. Fission reactors have the opposite problem: Their ability to produce a large amount of energy and rapidly accelerate a spacecraft runs up against the challenge of miniaturizing a fission reactor to be able to fit into a spacecraft. Fission engines combined with an electrical power source would ensure that thrust could be generated at all times, or at a moment’s notice, to change a craft’s direction. Both ion thrusters and nuclear fission may be combined with a rotating detonation rocket engine to generate enough initial energy to break through Earth’s gravitational pull to place spacecraft into orbit above Earth before beginning a journey to Mars.
Other nations like China have poured millions of state dollars into developing space resources, AI, robotics, and quantum computing for their satellites. By developing the technology to push our spacecraft further faster, the United States’ space capabilities will leave China in low-Earth orbit while the United States leads the way in traveling to Mars and advancing deeper into the solar system.
Roy Mathews is an Innovation Fellow at Young Voices. He is a graduate of Bates College and former Fulbright Fellow in Indonesia. He has been published in The Wall Street Journal, The National Interest, and the Boston Herald.