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DN-007 L: In situ measurements of the horizontal and vertical distribution, abundance, and physical makeup of shallow bulk water ice

Ground measurements of water ice in shadowed South Pole regions: how much there is, at what depth (in 20 cm steps to 1 m), how it varies across sites at least 50 m apart, and whether it is granular or in consolidated sheets. "There are no ground truth measurements". Without them NASA "will be unable to understand the abundance and accessibility of bulk water ice". It is named in the Moon Base Users Guide (near-term), under two challenges, "Securing sites" and "ISRU systems" (Data gaps spreadsheet, DN-007 L; Users Guide, pp. 12–13).

Quotations below are from row DN-007 L of the data gaps spreadsheet unless marked otherwise. ADD Rev C's Appendix E prints the same record as a table, and it matches the row field for field except for the wording of one sentence under "Impact if data is unavailable" (ADD Rev C, p. 271, PDF checked).

Description

"Measure the vertical and horizontal distribution and abundance of shallow bulk water as a function of depth in shadowed regions of the lunar south pole. Identify the physical makeup of the shallow water ice (i.e., granular vs. consolidated sheets). A series of direct, ground-based measurements should be taken at several different locations to support resource exploration on the lunar surface. This data gained over a limited area should be matched with orbital data to identify water-favorable sites at regional scales."

Data utility (white paper, Table Two): "To enable better identification of potential sites for in-situ resource utilization activities" (ACR25 data-gaps white paper, p. 3).

Need driver and data type

  • Need driver: Lunar Resource Exploration
  • Data type: In Situ Measurement

Target measurement parameters

"Water ice abundance with vertical resolution <20 cm depth intervals to 1 m depth, at least 50 m horizontal resolution (distance between sample sites), with a 1 wt% water ice abundance detection limit."

Current state of data

"There are no ground truth measurements that characterize shallow bulk water ice on the lunar surface."

Impact if data is unavailable

"Knowledge of water ice distribution and abundance is a critical input for ISRU system design, architecture analysis, and identification of potential water reserve sites. Without data, NASA will be unable to understand the abundance and accessibility of bulk water ice at the south pole. Therefore, Artemis missions will be unable to take advantage of in-situ water during lunar surface missions which increases uncertainty of water collection and extraction methods."

The ADD words the first sentence differently. ADD Rev C's table reads "Knowledge of water ice distribution and abundance is a critical input for both ISRU system design and architecture analysis and identification of potential water reserve sites" (p. 271, PDF checked). The sheet, quoted above, has "a critical input for ISRU system design, architecture analysis, and identification of potential water reserve sites". Both name ISRU system design, architecture analysis and the identification of water reserve sites; only the wording differs. Both documents are from December 2025. The wiki quotes the sheet and records the ADD's wording here (open question 38).

Benefits if data is available

"With direct, ground-based data covering a sufficient area and matched to orbital measurements, a predictive 'water favorability' model can be developed, generating a map of potential water concentrations and distributions at other locations. This is critical to the selection of favorable ISRU surface sites which can inform both ISRU systems and surface exploration activities."

Traceability

Priority

None. The spreadsheet has no priority field, and the Users Guide calls the data-gap list "not comprehensive or prioritized" (Users Guide, p. 11).

Moon Base relevance

The Users Guide names DN-007 L for two associated challenges (Users Guide, pp. 12–13):

  • "Securing sites" (p. 12): "Identifying, selecting, and landing at individual sites requires more data about the lunar surface, including regolith properties, high-resolution imagery, mapping, and resource locations." Also cited: DN-001 L to DN-006 L, DN-008 L to DN-010 L, DN-013 L and DN-014 L. No tech gap.
  • "ISRU systems" (p. 13): "Using local lunar resources to enable exploration requires both detailed knowledge of resource availability and systems to extract and process those resources." Also cited: data gap DN-006 L and tech gaps #0601, #0603, #0604 and #0605.

The guide ties its challenges to "near-term Moon Base development efforts": missions in phase one "offer opportunities to collect data and mature technologies to enable essential phase two and phase three capabilities" (p. 11). See Technology and knowledge challenges.

Phase 1 missions on the same subject (the wiki's link; no source pairs them): VIPER's 1-meter drill will "sample lunar soil at different depths and temperatures, searching for water ice and other volatiles", including in permanently shadowed craters (Moon Base Phases, "VIPER"). MoonFall's instruments will "search for water ice beneath the surface" (Moon Base Phases, "MoonFall"). See the data gaps index.

A Moon Base payload with no phase, same subject (the wiki's link): DISCO, selected through PRISM in September 2026, "will provide the first direct, on-the-ground measurements of ice hidden in lunar micro-cold traps" and pinpoint "where ice exists and how much of it is there". The release gives no site or depth (PRISM release, "DISCO").

Sources

Data gaps spreadsheet, DN-007 L · ACR25 data-gaps white paper, p. 3 · Users Guide, pp. 11–13 · Moon Base Phases, "VIPER", "MoonFall" · 2025 Architecture Update, p. 14 · ADD Rev C, pp. 202, 271