NASA officials announced Tuesday that they are seriously considering sending the full-scale engineering model of the Perseverance Mars rover to the Moon, equipping the vehicle with a nuclear power source to explore the south pole region.
The car-sized rover, nicknamed “Promise” (also known as OPTIMISM), currently resides at NASA’s Jet Propulsion Laboratory in California where it has served as a testbed for the Perseverance mission on Mars. If approved, the vehicle would be fitted with a multi-mission radioisotope thermoelectric generator (MMRTG) powered by plutonium-238, giving it the ability to operate through the two-week lunar night and traverse terrain that solar-powered rovers cannot reach.
“We are thinking very hard right now about sending Promise to the Moon,” NASA Administrator Jared Isaacman said during a monthly update on the agency’s plans to build a Moon base. “We have got the hardware, and this is exactly what we should be trying to do to put wins on the board, getting a capability like Promise to the surface of the Moon.”
The rover has a mass of about 1,000 kilograms (1 ton). Because of its size, it would likely need to be delivered by Blue Origin’s Blue Moon lander or SpaceX’s Starship. NASA already has an MMRTG available with a supply of plutonium-238 that is steadily decaying, creating a “use it or lose it” urgency around the proposal.
Carlos García-Galán, another NASA official spearheading the Moon base initiative, emphasized the strategic advantage of a nuclear-powered rover.
“That would be an awesome capability,” García-Galán said. “For Moon-based objectives, having a nuclear RTG on it allows us to go anywhere we want, regardless of the illumination. Surviving the lunar night is going to be one of the bigger challenges with this capability, we would not have to worry about that. So, long traverses getting into those very hard-to-reach areas, just like Curiosity and Perseverance have shown us on the surface of Mars, that would be awesome.”
No longer needed as a test bed?
Over the years, Promise has served as a physical duplicate for troubleshooting problems Perseverance might encounter on Mars. Commands are often tested on this vehicle in the Mars Yard at JPL before similar commands are sent to the rover on the Red Planet. But with years of operational experience now accumulated from both the Curiosity and Perseverance rovers on Mars, NASA believes the testbed hardware can be repurposed.
“It makes sense, early on, when we have got a problem that we might want to test it out here before we upload it to Mars,” Isaacman said. “But we have had years now of experience operating the two rovers on the surface of Mars, and we have got this hardware that the taxpayers invested a lot in. So the question was posed, what if we sent it to the Moon?”
JPL engineers have indicated that Promise could be modified to operate on the lunar surface. Some adjustments to the scientific instruments would be required, but Isaacman described the idea as a creative way to advance the agency’s lunar objectives.
Could do a lot of useful science
A nuclear-powered rover of this scale could accomplish numerous scientific and exploration goals. NASA studied similar concepts more than a decade ago with an “Endurance” rover proposal that would have traversed nearly 2,000 kilometers (1,240 miles) across the South Pole-Aitken basin on the far side of the Moon. That rover was never built.
The decision is not final, and NASA is still assessing the feasibility of using Promise as a mainstay of its lunar fleet. However, the announcement underscores that Isaacman and his team are scouring NASA for existing hardware to accelerate the agency’s mandate to return to the Moon and establish a surface base.
The space agency is effectively on a wartime footing as it seeks to land humans on the Moon’s south pole before China and to explore the most scientifically valuable terrain there first. Mars, for the moment, is not a near-term priority.
The Perseverance rover launched to Mars in July 2020. Its predecessor, the similarly sized Curiosity rover, launched to the Red Planet in November 2011. Both continue to operate on the Martian surface.