NASA Backs Development of Nuclear Space Engine for 45-Day Journey to Mars

NASA has endorsed the development of a nuclear space engine that could shorten the journey to Mars to just 45 days, significantly reducing the current travel time of seven months. The American firm SpaceNukes, in collaboration with the University of Michigan, is working on a new generation of nuclear electric propulsion systems that are 25 times more efficient than conventional rockets. Additionally, there is ongoing partnership with Ad Astra Rocket Company, whose VASIMR engine can achieve speeds of up to 197,950 km/h.

SpaceNukes is involved in the Space Power and Propulsion for Agility, Responsiveness, and Resilience (SPAR) program, which aims to develop nuclear electric propulsion technologies for future space exploration. This technology is intended for both military and civilian applications.

Nuclear electric propulsion systems harness a nuclear reactor to power an electric propulsion unit. According to SpaceNukes, these systems are 25 times more effective compared to traditional rockets.

One of the primary goals of the company is to create a spacecraft capable of maneuverability. Traditional rocket missions require meticulous planning of trajectories and engine thrust, but the implementation of nuclear electric rockets will allow for greater flexibility in these aspects.

In 2018, SpaceNukes successfully tested its Kilopower reactor utilizing Stirling technology (KRUSTY), showcasing a modular reactor designed for long-term space missions.

The partnership between SpaceNukes and the University of Michigan will focus on developing a second-generation reactor. The new design will be able to withstand higher operational temperatures for both the reactor core and radiators, which will significantly reduce the overall mass of the propulsion system.

SpaceNukes claims to be the sole American company that has designed, built, and tested a new nuclear reactor concept in the past half-century.

Another entity working on similar technologies is Ad Astra Rocket Company, founded by former NASA astronaut Franklin Chang-Diaz. They are developing a nuclear electric propulsion engine known as VASIMR. In a 2023 interview, Diaz stated that nuclear electric propulsion is «the only thing needed for humans to journey to Mars.» However, he mentioned that the project faces significant funding challenges, making investor acquisition a barrier.

Last year, SpaceNukes announced a partnership with Ad Astra to collaboratively develop these technologies. The VASIMR engine, powered by a nuclear reactor, is projected to accelerate a spacecraft to speeds of 197,950 km/h, theoretically allowing it to reach Mars in about 45 days, thus cutting the existing travel time estimates by sixfold.

Meanwhile, the American firm Howe Industries is developing a technology called the Pulse Plasma Rocket (PPR). The company states that this propulsion system can produce a thrust of up to 100,000 N at a specific impulse of 5,000 seconds, meeting two critical requirements for deep-space missions. This positions it as a promising candidate for future deep-space explorations.

In 2023, NASA approved the design for a nuclear electric propulsion system (NEP), which relies on a nuclear reactor to power a Hall effect thruster. This ion engine generates an electromagnetic field that ionizes and accelerates an inert gas (like xenon) to create thrust. This technology has been explored under NASA’s Nuclear Systems Initiative (NSI).

Furthermore, NASA’s Institute for Advanced Concepts has awarded a grant to the startup Positron Dynamics for the development of a new type of rocket called a nuclear fission fragment engine (NFFE). The projections suggest it would combine the power of chemical rockets with the long-term thrust of solar sails.