NASA is planning to send a repurposed version of its Mars rover testbeds to the moon. The new rover, called PROMISE (Polar Rover for Observation, Mapping and In-Situ Exploration), will be a hybrid of the engineering models of Perseverance and Curiosity. These full-scale replicas were originally built on Earth to test features for the Martian rovers, but now one of them could be adapted for lunar exploration.

The proposal was announced in late June, with NASA administrator Jared Isaacman explaining that the hardware has years of operational experience from Mars. PROMISE will scout the lunar south pole, a potential site for future bases due to abundant water ice. It will be equipped with a multi-mission radioisotope thermoelectric generator (MMRTG) powered by plutonium, allowing it to operate regardless of illumination and survive the harsh lunar night.

However, PROMISE is still a concept. The test model, previously called OPT IMISM, is not flight-ready. It lacks temperature control sensors, flight instruments, communications, and a generator, and its components aren't rated for abrasive lunar dust. Extensive upgrades are needed.

The Planetary Society estimates the mission would cost $700 million to $1.3 billion, with a launch not expected until the early 2030s. For now, NASA has not detailed the full upgrade process, but the rover's nuclear capability offers unprecedented exploration flexibility.