NASA Stops Work on VIPER Moon Rover, Citing Cost and Schedule Issues

NASA says it intends to discontinue development of its VIPER moon rover, due to cost increases and schedule delays — but the agency is also pointing to other opportunities for robotic exploration of the lunar south polar region.

The Volatiles Investigating Polar Exploration Rover was originally scheduled for launch in late 2023, targeting the western edge of Nobile Crater near the moon’s south pole.

The south polar region is a prime target for exploration because it’s thought to hold deposits of water ice that could sustain future lunar settlements. NASA plans to send astronauts to that region by as early as 2026 for the first crewed lunar landing since 1972.

Unfortunately, the VIPER project ran into a series of delays, due to snags in the testing and development of the rover as well as the Astrobotic Griffin lander that was to deliver the rover to the lunar surface. The readiness date for VIPER and Griffin was most recently pushed back to September 2025.

During an internal review, NASA managers decided that continuing with VIPER’s development would result in cost increases that could lead to the cancellation or disruption of other moon missions in NASA’s Commercial Lunar Payload Services program, or CLPS. NASA notified Congress of its intent to discontinue development.

The budgeted cost for building VIPER was $433.5 million, and the estimated cost of building and launching the Griffin lander is $235.6 million, according to a 2022 report from NASA’s Office of the Inspector General.

NASA said it will continue supporting Astrobotic’s Griffin Mission One, with launch set for no earlier than the fall of 2025. Instead of delivering VIPER, the mission would provide a flight demonstration of the lander and its engines. In January, Astrobotic’s Peregrine lander passed up an opportunity to land on the moon due to a problem with its propulsion system.

NASA said other missions could verify the presence of ice in the moon’s south polar region and determine how such resources could be used to further exploration goals.

“We are committed to studying and exploring the moon for the benefit of humanity through the CLPS program,” Nicola Fox, NASA’s associate administrator for science, said today in a news release. “The agency has an array of missions planned to look for ice and other resources on the moon over the next five years. Our path forward will make maximum use of the technology and work that went into VIPER, while preserving critical funds to support our robust lunar portfolio.”

Late this year, for example, Intuitive Machines is due to deliver an ice-mining experiment called PRIME-1 to the south pole under the terms of the CLPS program. PRIME-1 is designed to drill for water ice and study what happens to the H₂O when it’s brought up to the surface.

In league with NASA, the CLPS program and a wide array of other partners, the Canadian Space Agency is planning to send an ice-hunting rover to the lunar south polar region by as early as 2026. The Artemis program’s crewed missions will also study the moon’s ice deposits and how they can be used.

NASA said it plans to disassemble VIPER and arrange for the reuse of the rover’s components and scientific instruments for other missions to the moon. But prior to disassembly, the agency said it would consider expressions of interest from commercial and international partners for use of the existing VIPER rover system at no cost to the federal government. Interested parties can email HQ-CLPS-Payload@mail.nasa.gov anytime between July 18 and Aug. 1.

NASA said the VIPER team would conduct an “orderly close-out” through next spring.

Word of VIPER’s demise was met with disappointment in some quarters of the space community. “In the Artemis era, why is lunar science targeted for cancellation?” Laura Seward Forczyk, founder and executive director of the space consulting firm Astralytical, asked in a posting to the X social-media platform.

Phil Metzger, a planetary physicist at the University of Central Florida, said NASA was making a “bad mistake.”

“This was the premier mission to measure lateral and vertical variations of lunar ice in the soil,” Metzger wrote in a posting to X. “It would have been revolutionary. Other missions don’t replace what is lost here.”