The National Aeronautics and Space Administration has paused development of its PROMISE robotic lunar vehicle after proposals to recycle components from Mars rovers yielded unexpectedly high costs.
Total cost estimates for building and integrating the lunar surface exploration craft range between $723 million and $1.33 billion.
Casey Dreier, chief of space policy at the Planetary Society, calculated the budget figures during an official review of the NASA proposal. Dreier said the overall estimate includes between $234 million and $320 million for launch and landing operations, alongside extensive engineering expenses.
NASA planned the PROMISE vehicle as part of its lunar exploration program, which relies on specialized robotic vehicles to transport scientific instruments across the surface of the Moon. To lower costs, project planners sought to repurpose existing hardware rather than building a new vehicle from scratch.
Rising costs of hardware recycling
The proposed design aimed to combine engineering models developed for previous Mars missions, specifically MAGGIE and OPTIMISM. These test vehicles were originally built to help engineers evaluate hardware performance, software functions, and driving operations before the Curiosity and Perseverance rovers traveled to Mars.
Curiosity and Perseverance are NASA robotic rovers designed to explore the surface of Mars. Engineering models like MAGGIE and OPTIMISM serve as physical, Earth-bound stand-ins, allowing mission teams to test code and simulate driving conditions without risking spacecraft on another planet.
NASA Administrator Jared Isaacman did not challenge the entire proposal budget, but he indicated strong reservations about the projected expenditures. Isaacman said that if flying the PROMISE rover consumes 20 percent of its minimum budget, he would not allow the mission to fly.
Isaacman noted that launch and landing procedures carry substantial costs and that combining leftover hardware components creates exceptional technical complexity. However, he admitted that it would be crazy not to take advantage of hardware units that have already received hundreds of millions of dollars in investment.
Technical challenges and future outlook
Transforming ground test models into flight-ready lunar hardware requires substantial technical modification. Engineers must certify the hardware for launch, adapt existing communications equipment for lunar operations, and integrate a plutonium radioisotope power system to sustain the vehicle on the Moon.
Radioisotope power systems generate electricity from the heat produced by decaying radioactive isotopes, such as plutonium. These power sources enable space probes and rovers to operate during long lunar nights and in extreme planetary environments where solar power is insufficient.
Full details regarding the financial viability of the overall project remain secret, limiting public discussion of the budget. NASA officials indicated that the mission could still move forward if engineers successfully lower integration costs and resolve remaining technical hurdles.
