NASA Chief Rejects $1 Billion PROMISE Rover Estimate as Lunar Push Faces RTG Tradeoffs
Updated
Updated · SpaceNews · Jul 31
NASA Chief Rejects $1 Billion PROMISE Rover Estimate as Lunar Push Faces RTG Tradeoffs
2 articles · Updated · SpaceNews · Jul 31
Summary
Jared Isaacman said NASA would not fly PROMISE if converting the Mars-rover testbed cost even 20% of The Planetary Society’s $723 million low-end estimate, sharply disputing claims the lunar rover could top $1 billion.
The society’s analysis said turning JPL’s OPTIMISM model into a moon-ready rover would require major additions—space-rated communications, flight instruments and work to certify a spare RTG, lander changes and launch approval.
That spare RTG is central to the dispute because using it for PROMISE could block outer-planet science missions, while Isaacman argued it makes little sense to let Pu-238 decay about 2% a year awaiting a mission that does not exist.
NASA’s wider planning is already constrained by nuclear-power uncertainty: the agency has delayed its next New Frontiers mission call to fiscal 2027 while assessing which candidate missions could get RTG support.
Isaacman cast PROMISE as part of a broader Moon Base strategy to repurpose existing hardware quickly and deliver near-term lunar capabilities rather than wait for lengthy consensus-building.