NASA announced Wednesday it was pulling the plug on the VIPER (Volatiles Investigating Polar Exploration Rover) project. It was the second time in less than a decade, NASA scrapped plans for a roving scout to explore the Moon for water ice, the decision coming six years after cancelling a similar mission, the Resource Prospector.
The 430 kg (948 lbs.) rover was designed to fly to the Moon’s South Pole onboard Astrobotic’s Griffin lander, the second planned mission to the Moon for the Pittsburgh-based company. Astrobotics first mission, the smaller Peregrine lander, ended prematurely in January when a propulsion issue prevented it from reaching the Moon.
During a teleconference with members of the press, Joel Kearns, NASA’s deputy associate administrator for exploration within the Science Mission Directorate, pointed at ballooning costs as a big driver for the cancellation of VIPER.
“When we formalized the VIPER project, we told Congress that the budget for the project would be $433.5 million and that the landing would be at the end of 2023,” Kearns said. “We had already made the decision to reschedule landing for 2024 so that we could have Astrobotic do additional propulsion tests on the lander.
“When we made that decision, we updated the VIPER work plan and we reset the budget to $505.4 million with a landing at the end of 2024. But our latest estimate that was done earlier this year showed that since we were no longer planning to land VIPER at the end of 2024, but instead would have to do it for the science window 2025, that the cost for the VIPER project was projected to be $609.6 million.”
Kearns said ballooning past 30 percent of the original budget was a bridge too far and automatically triggered what he called a cancellation termination review, which was held in June. Back in 2019 when VIPER was first announced, NASA quoted the original estimate for the gold cart-sized rover at $250 million with a delivery to the Moon in 2022.
In a blog post in May 2024, Dan Andrews, the VIPER project manager, shared that in April the lander passed a system test readiness review, allowing VIPER to move onto stress tests and environmental testing.
“These environmental tests are important because they force our rover to experience the conditions it will see during launch, landing, and in the thermal environment of operating at the lunar South Pole,” Andrews wrote in May. “Specifically, acoustic testing will simulate the harsh, vibrational ‘rock concert’ experience of launch, while thermal-vacuum testing will expose VIPER to the hottest and coldest temperatures it will see during the mission, all while operating in the vacuum of space. It’s a tough business, but we have to make sure we’re up for it.”
During his comments on Wednesday, Kearns said that at this point, VIPER hadn’t completed system-level environmental tests and that some ground systems needed to operate the rover on the Moon weren’t complete either.
He said with the cancellation of VIPER, NASA would save a minimum of $84 million, “which is the cost to continue to finish the road for flight and ground systems and then operate the mission, which now can’t take place in 2024.”
When pressed on why this decision was being made when NASA has weathered budget increases of similar or greater amounts and not cancelled programs, Kearns said they were not only tied down by Congress’ budget constraints, but also that the quoted estimates might not be the end of the story.
“One of the concerns that we had was the immediate cost, that we would have to take out of something else in NASA Science in order to get ready for the September 2025 landing, but another concern we had was that the landing would not take place in September 2025 and if it took place later than November, it’d probably be taking place in 2026, which would probably require a similar amount of money to continue into 2026,” Kearns said.
A notable part of that timeline concern came from the fact that Kearns said the Griffin lander would be ready no earlier than September 2025.
“We took into account the fact also that it could be at least possible that the Griffin lander availability for launch could be delayed past September 2025. The Griffin lander itself would have to be able to launch by November 2025 or else it would miss the VIPER science operations window for that 100-day mission after it lands,” Kearns said. “VIPER can only take its measurements during particular conditions at the South Pole when there’s a lot of sunlight available, which we call South Pole summer, and also a way to communicate directly by radio back to Earth.”
“This is a challenge for any long-duration mission that will go to the South Pole that doesn’t use, say, nuclear power for heating and for power,” Kearns added. “You have to be very careful about how long you will be in darkness.”
What happens now?
NASA will maintain its $323 million contract with Astrobotic, which will allow Griffin Mission One to press forward towards launching in 2025. Kearns said the lander will now travel to the Moon with a mass simulator, which will weigh about the same as VIPER.
He added that Astrobotic can seek additional commercial payloads for the lander and if needed, the size of the mass simulator could be reduced to compensate.
“We decided at NASA, given the scope and schedule and the cost, the fixed-price cost that we’ve agreed with Astrobotic with the Griffin mission, that we will not substitute additional science instruments on Griffin because we feel that if we did, it might mean schedule delays and increased costs for the government,” Kearns said. “So our focus now on Griffin is to get the data out of the successful landing, of how their propulsion system works.”
When asked if VIPER could switch to another one of NASA’s booked lunar landers, like the cargo version of Blue Origin’s Blue Moon lander, Nicola Fox, the associate administrator for NASA’s Science Mission Directorate, said that could had negative budget impacts for other CLPS missions.
“It’s more about the cost risk and the threat to the rest of the NASA program,” Fox said.
She said NASA has informed appropriators in Congress about their decision and are awaiting their response.
In a post on X, formerly Twitter, Astrobotic stated that it aims to launch its Griffin lander in the third quarter of 2025. In April, the company announced that it would be launching its own shoebox-sized rover called CubeRover in partnership with the company, Mission Control, as part of Griffin Mission One.
The lander will also carry the LandCam-X payload on behalf of the European Space Agency and French startup, Lunar Logistics Services. It’s designed to “take pictures as it approached the Moon to improve the precision and safety of future lunar landings.”
Astrobotic hasn’t published a full list of its commercial customers yet.
