3 minute read•Updated 1:15 AM EDT, Thu April 24, 2025
The Defense Advanced Research Projects Agency (DARPA) has announced a call for proposals for an ambitious lunar orbiter project, known as Lunar Assay via Small Satellite Orbiter (LASSO).
The initiative aims to advance technologies critical for maneuvering spacecraft in exceptionally low lunar orbits while simultaneously prospecting for valuable lunar water ice reserves.
DARPA’s dual-purpose solicitation seeks to accomplish both technological advancement and practical exploration objectives. Specifically, the agency intends to demonstrate capabilities for spacecraft to navigate and operate at altitudes as low as 10 kilometers above the lunar surface.
At such low altitudes, spacecraft encounter considerable challenges due to irregularities in the Moon's gravitational field, necessitating frequent orbital adjustments to maintain stability.
"Sustained and advanced maneuverability for spacecraft is key to enabling further improvements of space situational awareness (SSA) in cislunar space," - DARPA Solicitation Document
Beyond technology demonstrations, LASSO’s mission will involve comprehensive mapping of lunar regions for concentrations of water ice. DARPA's objective is to achieve full lunar coverage within a maximum of four years, identifying locations with water ice concentrations exceeding 5%. The detection and accurate mapping of such reserves are vital for future missions, potentially supporting commercial lunar exploration and NASA's broader goals for sustainable lunar presence.
"by establishing new technologies that can offer increased maneuverability and SSA while also supporting commercial space capabilities and NASA missions by identifying the existence of proven reserves of water," - DARPA Solicitation Document
Interested organizations must initially submit six-page abstracts detailing their proposed mission concepts.
Selected candidates will then provide oral presentations, with DARPA planning to award contracts for an initial six-month Phase 1A conceptual design study. Subsequently, successful candidates will progress to an 18-month Phase 1B, culminating in a critical design review. The final Phase 2 will involve a one-year effort to construct the spacecraft.
DARPA will facilitate collaboration with NASA to launch the completed spacecraft, designed to fit the standard ESPA payload adapter commonly used for secondary payload deployments.
The initiative emerges amid ongoing NASA setbacks in lunar water ice exploration. NASA's Lunar Trailblazer, a smallsat launched in February 2025 to seek lunar ice, experienced technical issues immediately after launch, jeopardizing its primary science mission. Moreover, NASA's Volatiles Investigating Polar Exploration Rover (VIPER), initially slated for a lunar landing via Astrobotic’s Griffin lander, encountered significant delays and budget overruns. NASA is currently soliciting industry partnerships to deploy VIPER without additional cost to the agency.
Although DARPA’s solicitation does not specify a budget, it requires proposers to submit a preliminary cost estimate followed by a detailed, realistic budget breakdown during oral presentations.
The LASSO program is part of broader DARPA lunar efforts, including the 10-Year Lunar Architecture (LunA-10) project launched in 2023. LunA-10’s findings, covering vital lunar infrastructure and commercial economic frameworks, will be detailed in "The Commercial Lunar Economy Field Guide," slated for release in May.
Complementing LunA-10, DARPA also initiated the Lunar Operating Guidelines for Infrastructure Consortium (LOGIC), a global collaboration to develop commercial standards and infrastructure guidelines for lunar exploration.
