The LASSO initiative will test navigation and propulsion technologies at an altitude of just ten kilometers above the lunar surface, and will help map subsurface ice deposits with a concentration of 5% or more.
DARPA, the advanced development arm of the US Department of Defense, issued a request for proposals on April 14 for the design of a small water-cracking satellite that could serve as a platform for testing spacecraft performance in very low lunar orbit while detecting subsurface ice deposits. The mission, called Lunar Assay via Small Satellite Orbiter (LASSO), consists of two main components: practicing maneuvers in extremely low layers above the moon and mapping water concentrations below the surface (SpaceNews).
According to the order documents, the technological part will focus on the navigation and propulsion capabilities required to ensure stable flight in a low-altitude orbit of only about 10 kilometers above the lunar surface. At these altitudes, the effects of the inhomogeneous gravitational fields of the lunar masses (mascons) create constant instability, requiring active engine firings every few hours to maintain a safe trajectory. This skill is also expected to benefit the new branch of the US Space Force (USSF), which seeks to expand spatial awareness (SSA) in the region between the Earth and the Moon.
At the same time, LASSO will fully map the lunar surface to discover areas where the concentration of underground water is at least 5% by volume, in sections no larger than about 4 square kilometers. The goal is to complete scanning the entire lunar surface within a maximum of four years, and to identify water deposits “of a size and certainty that will justify the investment and energy required to extract them.” An accompanying economic study will compare the costs of transporting water from Earth versus the costs of obtaining water directly from the Moon, in preparation for the development of future water infrastructure.
To this end, DARPA is calling on organizations to submit six-page program summaries, followed by oral presentations. The initial selection will proceed to a six-month conceptual design phase (Phase 1A), followed by an 18-month critical design phase (Phase 1B). At the end of the process, only one vendor will be selected for the year-long construction phase (Phase 2), at the end of which DARPA’s involvement will end with a planned launch in collaboration with NASA. The structure must fit into the ESPA interface, an accepted standard for launching secondary satellites.
DARPA’s efforts come after setbacks and disruptions to previous NASA ice-mapping projects. The Lunar Trailblazer mission, which launched on February 26, encountered serious problems in the first hours after launch, and a final update on March 12 said that the primary research objective “is now not possible.” Also, the VIPER project, which was designed to sniff out ice in the lunar south pole region, was postponed to July 2024 due to budget and schedule issues, and NASA is now looking for commercial partners to launch it at no additional cost.
The LASSO initiative fits into the framework of broader cultural DARPA projects for lunar legislation: the LunA-10 (10-Year Lunar Architecture) project for a year of comprehensive planning for lunar infrastructure, the results of which will be published as “The Commercial Lunar Economy Field Guide,” and the LOGIC consortium, which is experimenting with defining standards for commercial lunar infrastructure issues.
According to Michael Nyack, project manager at DARPA, “LASSO will contribute to the development of technologies that will add maneuverability and SSA, and will assist commercial systems and NASA missions in locating verified water deposits.”
The deadline for submitting abstracts is set for May 27, 2025.
