Novel propulsion systems are one of the most important ways to push space exploration forward – literally. Traditional propulsion systems, like chemical rockets, are good at getting spacecraft out of gravity wells but not so great at traveling in free space. More modern systems, like electric propulsion, are better at providing long-term propulsion but are very slow. Others haven’t even made it to space, like nuclear thermal rockets. But there’s one type that could trump them all – fusion propulsion. It has the benefit of significant thrust and excellent fuel efficiency and could open up the whole solar system in ways other systems could only dream of. One company, Helicity Space, thinks they are on the path to developing a working version of just such a fusion propulsion system, and they just received a NASA Institute of Advanced Concepts (NIAC) grant to continue its development.
The NIAC grant itself focuses on exploring the heliosphere—an area surrounding the Sun (including on top of it) that our star influences. It is huge in terms of the amount of space covered and not well understood because, typically, missions only stay in the plane of the ecliptic, and if they go far enough to reach the outer stretches of the heliosphere, it is only after decades of travel, like the Voyager space probes.
Helicity proposes using fusion rockets to send a constellation of spacecraft to all parts of the heliosphere with sensors to detect things such as plasma properties, the amount of energetic particles, and the amount of dust in a given region. This constellation could provide heliophysics with a much more complete picture of what the heliosphere looks like.
However, the real innovation the NIAC grant focuses on isn’t sensor instrumentation but the propulsion system. Fusion propulsion has been a dream of many space exploration enthusiasts for decades. Still, it has seemed to suffer from the same fate of technical development hell that its ground-based cousins, the large-scale power-positive fusion plants, have. The physics of plasma constraint and forced fusion are challenging, to say the least, so projects like the International Thermonuclear Experimental Reactor (ITER) cost billions of dollars and take decades to complete.
Helicity, on the other hand, is a scrappy start-up based in Pasadena, and they believe they can produce a functioning fusion engine well before ITER hits its full power in 2035. In an interview with Fraser, Setthivoine You, the company’s co-founder and chief technologist, explains that if you’re trying to make money from a fusion power plant, “you need to do net gains of 20, 30, 40, 50 [times] more fusion energy out than what you put in [and] you have to do it every single second, 24 hours a day, 365 days a year.”
On the other hand, Helicity’s engine doesn’t have to operate constantly and can produce net gains of only 10x, and only occasionally. In such an operational mode, the engineering challenge becomes much more tractable. The company has already built a prototype unit at its facility in Pasadena and has been presenting at several conferences and publishing academic papers detailing its progress all along.
Credit – Isaac Arthur YouTube Channel
The NIAC grant will allow them to start fleshing out the technical details of what the engine would require to complete the heliosphere mission, allowing them to tweak the engine to get to those performance metrics. But that’s not the only mission this system can be used for. Getting to Mars in about a month and a half, rather than the nine months using traditional propulsion, has been one of the space exploration community’s main selling points to such a system.
During the interview, Fraser mentioned even more outlandish missions, like one to the solar gravitational lens point, where we could use the Sun’s gravitational lensing effect to image exoplanets around other stars directly. Dr. You mentioned, “Our proposal could take us out there in less than 10 years”, dramatically shorter than any currently proposed propulsion system. Unlike alternatives like giant solar sails, it would also have the added benefit of slowing down and holding its position.
In addition to the advanced propulsion system, though, Helicity mentions developing additional technologies that could directly benefit people back on the ground as part of their proposal. Dr. You mentions “high-high solid-state switches, energy storage, systems, [and] magnetic coils” as potentially useful tools that would result from the development of the engine.
Credit – Helicity Space
Much of the challenges facing the development team appear to focus on developing these “subsystems inside plasma sources,” which is one particular challenge Dr. You calls out, along with several other engineering challenges. Basically, proving the engine will work in space is the biggest technical hurdle at this point – and the Phase I NIAC grant is another step towards doing so.
It is not the first step, however—Helicity is backed by several VC firms and large aerospace companies, including Airbus and Lockheed Martin. The fact that they already have an experimental system up and running also lends credence to their ability to execute the mission of bringing fusion power to space. If they manage to do so, a long-held dream of space exploration enthusiasts will be realized, and the whole solar system will be opened up for human use.
Learn More:
NASA / Helicity Space – Fusion-Enabled Comprehensive Exploration of the Heliosphere
Helicity Space – Technology
UT – Magnetic Fusion Plasma Engines Could Carry us Across the Solar System and Into Interstellar Space
UT – Impatient? A Spacecraft Could Get to Titan in Only 2 Years Using a Direct Fusion Drive
Lead Image:
Image of the heliosphere and an artist’s concept of the fusion drive ship that could be sent to monitor it.
Credit – NASA / Helicity Space
