Strategic partnership brings high-energy nuclear-electric propulsion closer to reality

Propulsion technology is key to exploring the outer solar system, and many organizations are working on developing new technologies. One company with a long track record is Ad Astra Rocket Company, which has been developing the Variable Specific Impulse Magnetic Plasma Rocket (VASIMR) system for decades. But this type of electric propulsion system requires a lot of energy, so the company chose a unique partnership with a power plant that could solve that problem: a nuclear reactor.

Ad Astra recently entered into a strategic partnership with Space Nuclear Power Corporation (SpaceNux), which is responsible for developing the Kilopower Reactor, a 1kW nuclear reactor used in space missions.

There are many synergies that justify such a partnership between the two companies, but to understand why, let’s look at each technology in turn. The propulsion system VASIMR, which Ad Astra has been developing for more than 20 years, is a magnetoplasma rocket, a type of electric propulsion system.

Ion drives are the most commonly known form of electric propulsion and are known to be extremely fuel efficient. They aren’t powerful enough to lift a spaceship out of a planet’s gravity well, but once they enter space, where there is almost no gravity, they glow with long bursts of slow acceleration that translate to huge speeds if engaged long enough.

The problem is that it requires a lot of power. The fuel needs to be ionized, which requires a lot of energy, and that energy is hard to come by when you’re not connected to the power grid. Current solutions are either solar panels, which would require vast areas to power something like VASIMR, or have been popular for years to power systems on various spacecraft such as Voyager and Voyager. It utilizes one of the radioisotope thermal generators (RTGs) that have been used extensively. It has the patience but cannot provide enough power for a viable electric propulsion system.

Enter another form of nuclear energy, the traditional kind. SpaceNukes has been working on developing kilopower reactors in various guises for more than a decade, and in 2018 demonstrated the system’s ability to function at 1kW of power in ground systems. We are currently working with the U.S. Space Force under a project called JETSON. Develop a 12kW design for use in flight demonstrations.

VASIMR has the potential to significantly increase the efficiency of rockets as power increases above 100kW. The partnership between the two companies seems appropriate, as nuclear reactors are the only viable option for obtaining such power in space. However, there is still a long way to go before a 100kW system can be flight tested. The company’s press release announcing the memorandum said it hopes to conduct flight demonstrations and commercialize the technology “by the end of the decade.” “In the 2030s”

If they can hit that schedule, and it’s still a big assumption, the combination of VASIMR and kilopower-powered spacecraft could achieve the nuclear-electric propulsion dream that excites many space propulsion enthusiasts. It will be. This could reduce travel time to and from Mars from more than a year to a few months, allowing for more and better missions to the outer solar system, including interesting moons like Enceladus and Titan. .

Given both companies’ track record of slow and steady improvements, it seems likely that this technology will eventually see the light of day and enable a revolution in space propulsion. They must keep moving forward, like an engine that hopes to fly someday.