DARPA Seeks Proposals for Lunar Water-Prospecting Satellite

The Defense Advanced Research Projects Agency (DARPA) has issued a solicitation for proposals to develop a small lunar orbiter called Lunar Assay via Small Satellite Orbiter (LASSO). The mission has dual objectives: testing navigation technologies for very low lunar orbits and mapping the moon's surface for water ice concentrations. DARPA's solicitation, released April 14, outlines a multi-phase development process that could ultimately result in a spacecraft capable of operating just 10 kilometers above the lunar surface.

The LASSO initiative explicitly connects to U.S. military interests, with DARPA noting that technologies developed would support the Space Force's cislunar space situational awareness capabilities. The solicitation states that "sustained and advanced maneuverability for spacecraft is key to enabling further improvements of SSA in cislunar space." This represents part of the expanding U.S. military interest in monitoring and potentially controlling the space between Earth and the moon as various nations increase their lunar activities.

The water-prospecting aspect of the mission aims to identify lunar regions with at least 5% subsurface water ice concentration, resources that could support future NASA missions and commercial lunar operations. DARPA's approach contrasts with NASA's recent struggles in this area, including the technical problems with the Lunar Trailblazer satellite launched in February and the cancellation of the VIPER rover mission on Astrobotic's Griffin lander due to cost and schedule issues. DARPA plans to hand off the completed spacecraft to NASA for launch arrangements.

LASSO represents DARPA's latest lunar initiative, following its 10-Year Lunar Architecture (LunA-10) project announced in 2023 and the subsequent Lunar Operating Guidelines for Infrastructure Consortium (LOGIC). Michael Nayak, a DARPA program manager, revealed at the 40th Space Symposium that the results of LunA-10 will be published in May as "The Commercial Lunar Economy Field Guide." These initiatives reflect growing U.S. government interest in establishing infrastructure and capabilities on and around the moon, with potential implications for both national security and commercial development.

The LASSO procurement process will begin with six-page abstracts and oral presentations, followed by selection of multiple organizations for six-month conceptual design studies. After an 18-month phase to advance concepts through critical design review, DARPA expects to select one provider for a one-year spacecraft construction effort. While the solicitation does not specify a budget, it requires proposals to include cost estimates that are "reasonable, realistic, and affordable," indicating the agency's intent to move forward with actual development rather than just conceptual studies.