NASA Administrator Jared Isaacman has pushed back on reports that a recycled Moon rover project could cost around $1 billion. According to the available details, he said the agency would not proceed if that estimate is anywhere close to accurate.

The idea under discussion appears to involve converting two Mars rover engineering testbeds into a single vehicle for lunar exploration. On paper, reusing existing hardware might sound like a cheaper path, but the reported price tag suggests that adapting those systems for the Moon could become far more expensive than expected.

Isaacman’s reaction highlights a broader issue for NASA: repurposing old designs does not automatically guarantee savings. Engineering changes, mission requirements and the difficulty of making equipment work in a different environment can quickly raise costs, even when the starting point is hardware that already exists.

For now, the strongest signal from NASA’s leadership is that affordability will be a deciding factor. If the recycled Moon rover estimate remains near the level being discussed, the project may struggle to move forward in its current form.