Nuclear power could cut travel time to Mars to just 45 days from seven months. Here’s the twist

NASA is reviving research on 70-year-old nuclear thermal technology to accelerate manned trips to the Red Planet. The agency plans to collaborate with contractors to test a nuclear-powered rocket in space by 2027. 

In partnership with the US Department of Defense’s Defense Advanced Research Projects Agency (DARPA), NASA has enlisted Lockheed Martin to design, build, and test this advanced nuclear thermal rocket technology, which aims to cut travel time while operating with twice the efficiency of conventional chemical rockets that rely on fuel and oxidizers for propulsion. 

NASA intends to deploy a prototype system in space by 2027, potentially marking it as one of the first of its kind developed and operated by the US. 

A nuclear thermal rocket could deliver high thrust similar to chemical propulsion but with up to three times the efficiency. This means that instead of the current minimum of seven months to reach Mars, a nuclear-powered journey could take just 45 days. Additionally, NASA is exploring the potential for an efficient Earth-to-Moon connection, making this technology even more beneficial.

The agency is exploring two nuclear propulsion systems: nuclear electric and nuclear thermal.  

Nuclear electric propulsion systems use propellants more efficiently than chemical rockets but produce lower thrust. They generate electricity from a reactor, which charges gas propellants like xenon or krypton, ejecting ions through a thruster to propel the spacecraft forward. This low-thrust approach allows for prolonged acceleration, enabling a Mars mission to use significantly less propellant than high-thrust systems. 

“While NASA’s immediate focus is on returning humans to the Moon with the Artemis program, we are also investing in ‘tall pole’ technologies that could support crewed missions to Mars,” said Jim Reuter, associate administrator of NASA’s Space Technology Mission Directorate (STMD). “We’re eager to see the innovations industry can bring to nuclear propulsion and fission surface power in response to our upcoming request for proposals.” 

To date, only robotic missions have reached Mars, eliminating the need for a return trip. Astronauts would have to wait over a year for optimal planetary alignment to return, extending a round-trip mission to over three years. 

NASA aims to minimise crew travel time between Earth and Mars to around two years. Space nuclear propulsion systems could significantly shorten total mission durations and offer greater flexibility and efficiency in mission planning. 

“The reactor at the heart of a nuclear thermal propulsion system presents a major technical challenge due to the extremely high temperatures required for optimal performance,” explained Anthony Calomino, NASA’s nuclear technology portfolio lead within STMD. 

While most of the engine operates at moderate temperatures, materials in direct contact with the reactor fuel must withstand temperatures exceeding 4,600 degrees Fahrenheit. NASA and the Department of Energy are collaborating with industry to develop effective strategies, and industry partners will create preliminary designs to address this challenge.