NASA’s announcement yesterday that it would kill its $600 million VIPER lunar rover, even after it had been fully assembled, shows how the agency’s budget for planetary science has been strained to the breaking point. And some are questioning the decision, suggesting there are other ways NASA could have saved money.
But the cancellation of the water-hunting rover, which was meant to ride on a privately developed lunar lander, is also a warning sign about the viability of a far bigger agency effort, its $2.6 billion Commercial Lunar Payload Services (CLPS) program, says Clive Neal, a lunar scientist at the University of Notre Dame. “It’s on the edge right now.”
NASA began CLPS in 2018, in the hopes that it would stimulate companies to provide cheap, reliable access to the surface of the Moon. Although the development of the commercial landers would initially be supported by NASA-funded payloads, the space agency’s officials hoped they would lead to the creation of a market where academics or other companies would pay to put instruments, experiments, or even infrastructure on the Moon. But private customers have been slow to materialize, and with NASA canceling one of the biggest CLPS payloads, the whole program has been put on notice, says Amy Fagan, a planetary scientist at Western Carolina University. “If they are willing to cancel this very large payload, what else will be easy for them to cancel?”
NASA has always said CLPS would be risky, and the first two missions have proved that out. The first lunar lander, built by Astrobotic, failed to reach the Moon in January, and the second, developed by Intuitive Machines, toppled over upon landing a month later. The failures have forced scientists to temper their hopes for CLPS, Fagan says. “That was a wake-up call for some scientists, who really were skipping over rainbows thinking this was the next big thing.”
VIPER, which stands for Volatiles Investigating Polar Exploration Rover, was built out of instruments first intended for another lunar rover, the Resource Prospector, which NASA canceled in 2018, before it could be built. VIPER was then “shoehorned” into the nascent CLPS program, Neal says, but ambitions for it also grew. The rover grew from the size of a golf cart to a small car, and it was capable of operating for 100 days and surviving the frigid weekslong lunar night. Armed with a drill and instruments that could directly detect water, it would have mapped ice at the lunar south pole that could in the future be used by U.S. astronauts.
This ambition meant costs for the rover grew from $434 million to what would have been more than $600 million by the time it launched on Astrobotic’s Griffin lander in September 2025, Joel Kearns, deputy associate administrator for exploration in NASA’s science division, said yesterday in a press conference. Combined with the $323 million provided to Astrobotic for the launch and landing of the rover, that meant the mission would cost close to $1 billion—with nearly all of that money already spent. The completed rover was in the last stages of mission preparation, undergoing testing to ensure it could withstand the rigors of the lunar environment. Canceling the mission now will save $84 million, and possibly more if its launch had been further delayed, Kearns estimated.
The cost savings seem so minimal, given the impact the decision will have on lunar science, Fagan says. Similar savings could come from delaying or eliminating one future CLPS mission, she noted. “A lot of people I’ve talked to are a little perplexed,” she says. “We’re trying to wrap our brains around it.”
The move comes as NASA’s planetary division has been reeling from the collision of inflation and budget cuts dictated by a debt ceiling deal that President Joe Biden’s administration struck with Republicans in the House of Representatives last year. Many missions have been delayed, and its flagship Mars Sample Return mission, costing up to $11 billion, has been effectively suspended until engineers can find ways to make it cheaper. Although lawmakers have enthusiastically supported lunar exploration, they cannot hide from the part they have played in killing VIPER, Neal says. “Congress really has to take some of the blame.”
This does not signal the end of NASA’s desire to explore the Moon’s ice, Nicky Fox, its science chief, said yesterday. “Despite what’s happening with VIPER, we are committed to continue to study the Moon and to look for water and ice in all of our future missions.” But the scientific results from VIPER won’t easily be reproduced. The PRIME-1 lander, developed by Intuitive Machines and scheduled for launch late this year, will carry a version of Viper’s drill and mass spectrometer, but it is a technology demonstration, going to an area where water is unlikely to be seen. Lunar Trailblazer will launch later this year to map ice near the south pole, but it is a small scouting satellite that will struggle to match the ground-truthed evidence of a rover. “The science from Viper far exceeds what we get from the other CLPS missions combined,” Neal says. He adds that Viper would also have lured CLPS customers, as it would have demonstrated not only the reliability of an Astrobotic lander, but also the reality of proven lunar water reserves.
In its press conference, NASA made an unusual offer for an international space agency or company to take over the rover, but they must express interest by 1 August. Otherwise, the agency will disassemble the rover for parts, repeating what happened with the Resource Prospector. “It’s déjà vu all over again,” Fagan says.
Meanwhile, Astrobotic will still go ahead with its demonstration of the large Griffin lander, potentially carrying a dummy mass instead. Astrobotic’s CEO, John Thornton, told Space News the company might seek instead to demonstrate vertical solar panels that can catch the Sun’s low-angled rays at the lunar poles, something that Congress has been directing NASA to pursue.
The cancellation comes as China has landed several rovers on the Moon, including on its far side. Its next missions will target water resources on the south pole in order to site its future lunar research station. Neal fears NASA is losing the latest space race. “We cancel the only prospecting mission that will give us worthwhile information,” he says. “We’re now ceding leadership in exploration of the south pole.”
