 Artist's impression ofVIPER operating in darkness. | |
| Names | Volatiles Investigating Polar Exploration Rover |
|---|---|
| Mission type | Exploration, resource prospecting |
| Operator | NASA |
| Website | https://www.nasa.gov/viper |
| Mission duration | 100 days (planned)[1][2][3] |
| Spacecraft properties | |
| Spacecraft type | Roboticlunar rover |
| Manufacturer | NASA Lyndon B. Johnson Space Center |
| Dry mass | 430 kg (950 lb)[4] |
| Dimensions | 2.45 m (8 ft 0 in) in height, 1.53 m (5 ft 0 in) in length and width[5] |
| Start of mission | |
| Launch date | 2027 (Planned) |
| Rocket | New Glenn |
| Launch site | Cape Canaveral Space Force Station,LC-36 |
| Contractor | Blue Origin |
| Moon rover | |
| Landing date | 2027[6] |
| Landing site | Mons Mouton,South pole region[7][2] |
| Instruments | |
| Neutron Spectrometer System (NSS) Near InfraRed Volatiles Spectrometer System (NIRVSS) The Regolith and Ice Drill for Exploring New Terrain (TRIDENT) Mass Spectrometer Observing Lunar Operations (MSolo) | |
VIPER (Volatiles Investigating Polar Exploration Rover) is alunar rover developed at the NASAAmes Research Center. The rover would be tasked with prospecting forlunar resources inpermanently shadowed areas oflunar south pole region, especially by mapping the distribution and concentration ofwater ice. The mission built on a previous NASA rover concept, theResource Prospector, which had been cancelled in 2018.[8]
VIPER was to be carried aboard Astrobotic'sGriffin lander as part of NASA'sCommercial Lunar Payload Services (CLPS) initiative.[9]
In 2025, NASA released an Announcement for Partnership Proposal seeking U.S. companies to deliver and operate the completed VIPER rover on the Moon.[10] On September 19, 2025, NASA selectedBlue Origin to carry VIPER to the Moon.[11]
Amidst cost growth and delays to readiness of the rover and the Griffin lander, the VIPER program was ended in July 2024, with the rover planned to be disassembled and its instruments and components reused for other lunar missions. Before commencing disassembly, NASA announced they would consider "expressions of interest" from industry to use the "VIPER rover system at no cost to the government."[6] At the time of the announcement NASA expected to save $84 million by canceling the mission, which has cost $450 million so far.[12] The budgeted cost to build VIPER was $433.5 million, with $235.6 million budgeted to launch the lander.[13] The agency still plans to support the Griffin lander to arrive on the Moon in fall of 2025, though with Astrolab' FLIP rover in place of the VIPER rover.[14] NASA expects the primary objectives of VIPER to be fulfilled by an array of other missions planned for the next several years, but these may eventually become overshadowed and forgotten over time.[13]
VIPER's abrupt cancellation was received poorly by the scientific community. At the time of its cancellation, VIPER had been fully assembled and completed vibration testing.[15] In response, a letter opposing the cancellation was circulated and garnered over 2500 signatures by the end of July 2024.[16] In August 2024,The Planetary Society published a statement calling for the program to be reconsidered.[17] On September 6, 2024, theHouse Committee on Science, Space, and Technology published a letter requesting additional information as to why NASA cancelled the mission.[18]
In February 2025, NASA announced a new approach to potentially revive the VIPER mission through an industry partnership. The agency released an Announcement for Partnership Proposal seeking U.S. companies to deliver and operate the completed VIPER rover on the Moon. Under the proposed partnership, NASA would provide the already-built VIPER rover while the selected company would be responsible for the launch, landing, and surface operations, including data collection and dissemination, as well as all mission costs.[10] As of May, 2025, discussions are still ongoing but collapsed.
With the potential cuts from the second Donald Trump administration looming, the future of VIPER remains unclear. It is possible that the VIPER mission could be scrapped, and the team behind it face dismissal, and the VIPER name to be reused in unrelated contexts.
On September 19, NASA announced the awarding of aCommercial Lunar Payload Services (CLPS) task order toBlue Origin, a commercial NASA partner that is a part of theArtemis Program[19] using theirBlue Moon MK1 Lander to land at the south pole of the Moon. As a part of this task order, Blue Origin has the option to deliver the rover to the Lunar surface.[20] Both NASA and Blue Origin have expressed eagerness in including VIPER as a part of the mission,[21][22] but it is likely that the ultimate decision to include VIPER relies on the success of thefirst mission of the Blue Moon MK1 Lander, another CLPS mission.[23]
_and_north_pole_(right).webp)
TheVIPER rover has a size similar to a golf cart (around 1.4 × 1.4 × 2 m), and would be tasked with prospecting forlunar resources, especially forwater ice, mapping its distribution, and measuring its depth and purity.[1][2] The water distribution and form must be better understood before it can be evaluated as a potential resource within any evolvable lunar or Mars campaign.[24]
TheVIPER rover would operate on the western edge ofNobile crater onMons Mouton in the Moon'ssouth pole region.[7][25] The first rover with its own lighting source,[26] it was planned to rove several kilometers, collecting data on different kinds of soil environments affected by light and temperature—those in complete darkness, occasional light and in constant sunlight.[27][2] In permanently shadowed locations, it would operate on battery power alone and would not be able to recharge them until it drives to a sunlit area. Its total operation time was planned to be 100 Earth days.[1][2][3]
TheVIPER rover was part of the Lunar Discovery and Exploration Program managed by theScience Mission Directorate atNASA Headquarters, and was meant to support the crewedArtemis program.[2] NASA'sAmes Research Center was managing the rover project. The hardware for the rover was designed by theJohnson Space Center, while the instruments were provided by Ames, Kennedy, andHoneybee Robotics.[2] The project manager was Daniel Andrews,[2][28] and the project scientist was Anthony Colaprete, who was implementing the technology developed for the now cancelledResource Prospector rover.[29] The estimated cost of the mission was US$250 million in October 2019.[3] NASA said on 3 March 2021 that the new lifecycle cost for the mission was US$433.5 million.[30]
Both the launcher and the lander were competitively provided throughCommercial Lunar Payload Services (CLPS) contractors, with Astrobotic providing the Griffin lander to deliver the rover, and SpaceX providing the Falcon Heavy launch vehicle.[31] NASA was aiming to land the rover in September 2025 until the mission was canceled on 17 July 2024.[6][32]
In February 2024 the final instrument, the TRIDENT drill, was installed into the rover.[33] Later on 28 February 2024, VIPER Project Manager Dan Andrews announced that all the rover's scientific instruments were installed, and that it was more than 80% built.[34] Further progress was reported in April 2024, remaining on track for launch later in the year.[35] The rover moved to the environmental testing phase in May.[36]
At the lunar south pole VIPER will collect images and make neutron measurements while traveling between locations of interest.[37] At those locations the rover will shift to "Prospecting” mode, allowing higher fidelity measurements. The rover will be capable of:
Data obtained byLunar Prospector,[38]Lunar Reconnaissance Orbiter,Chandrayaan-1, and theLunar Crater Observation and Sensing Satellite, revealed thatlunar water is present in the form of ice near the lunar poles, especially within permanently shadowed craters in thesouth pole region,[39][40] and present in the form of hydrated minerals in other high-latitude locations.[41]
Water may have been delivered to the Moon over geological timescales by the regular bombardment of water-bearingcomets,asteroids andmeteoroids,[42] or continuously producedin situ by the hydrogen ions (protons) of thesolar wind impacting oxygen-bearing minerals.[38] The physical form of the water ice is unknown, but some studies suggest that it is unlikely to be present in the form of thick, pure ice deposits, and may be a thin coating on soil grains.[43][44][40]
If it is possible to mine and extract the water molecules (H
2O) in large amounts, it can be broken down to its elements, namely hydrogen and oxygen, and form molecular hydrogen (H
2) and molecular oxygen (O
2) to be used as rocket bi-propellant or produce compounds formetallurgic and chemical production processes.[45] Just the production of propellant, was estimated by a joint panel of industry, government and academic experts, identified a near-term annual demand of 450 metric tons of lunar-derived propellant equating to 2450 metric tons of processed lunar water, generating US$2.4 billion of revenue annually.[46]
TheVIPER rover will be equipped with a drill and three analyzers. The Neutron Spectrometer System (NSS), will detect sub-surface water from a distance, then,VIPER will stop at that location and deploy a 1 m (3 ft 3 in) drill called TRIDENT to obtain samples to be analyzed by its two onboardspectrometers, MSolo and NIRVSS.[2][3][47] Previously a TRIDENT drill and MSolo mass spectrometer were incorporated into thePRIME-1 payload of the unsuccessfulIM-2 lunar landing mission.[48]
| Instrument name | Abbr. | Provider | Function[49] |
|---|---|---|---|
| Neutron Spectrometer System | NSS | Ames Research Center (NASA) | Detect sub-surface hydrogen (potentially water) from a distance, suggesting prime sites for drilling |
| The Regolith and Ice Drill for Exploring New Terrain | TRIDENT | 1-m drill to obtain subsurface samples | |
| Near InfraRed Volatiles Spectrometer System | NIRVSS | Ames Research Center (NASA) | Analyze mineral and volatile composition |
| Mass Spectrometer Observing Lunar Operations | MSolo | Kennedy Space Center (NASA) | Analyze mineral and volatile composition |
NSS measures the energy released by hydrogen atoms when struck byneutrons. It was developed for the cancelledResource Prospector rover.[24]
The TRIDENT drill contains two temperature sensors, one at the tip and one about 20 cm (7.9 in) up. In addition to drilling and bringing up samples for NIRVSS and MSolo, its temperature sensors can measure the subsurface temperature. Combined with its heater element, TRIDENT can measure the thermal conductivity of the regolith. In addition, measuring the force necessary to drill reveals geotechnical properties of the regolith.[50]: 17
NIRVSS will determine if the hydrogen it encounters belong to water molecules (H2O) or tohydroxyl (OH−). Originally developed for theResource Prospector rover.[24]
Sub-systems: Spectrometer Context Imager (a broad-spectrum camera); Longwave Calibration Sensor (measures surface temperature at very small scales).
MSolo will measure themass-to-charge ratio ofions to elucidate the chemical elements contained in the sample. The instrument was created through a collaboration withINFICON, in which one of their mass commercial spectrometers was modified to make it suitable for spaceflight.[50]: 9
VIPER is a limited-time mission; operating at the poles means there's no sunlight to harvest with solar panels, so the rover will carry all the power it needs to last 100 days there.
This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain.| Missions |
| .svg) | ||||
|---|---|---|---|---|---|---|
| Agencies | ||||||
| Facilities | ||||||
| Rockets | ||||||
| Crewed spacecraft | ||||||
| Robotic spacecraft | ||||||
