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DN-015 L: Flux and size measurements of lunar meteoroid ejecta

Continuous measurement at the South Pole of the particles thrown up when meteoroids hit the Moon: speed (0.1–4.8 km/s), mass, direction and frequency. Ejecta is more abundant than the primary meteoroids, though slower, and can damage landers, rovers, habitats and suits. The only direct attempt, Apollo's LEAM, "did not conclusively detect impacts". It is named in the Moon Base Users Guide (near-term), under the long-duration challenge (Data gaps spreadsheet, DN-015 L; Users Guide, p. 12).

Quotations below are from row DN-015 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 (ADD Rev C, p. 279).

Description

"Measure the mass and velocity range of particles ejected via impact processes from primary meteoroids on the lunar surface. Continuous measurements should be taken at the lunar south pole to evaluate the risk these particles pose to human exploration activities."

Need driver and data type

  • Need driver: Lunar Surface Natural Environment Characterization
  • Data type: In Situ Measurement

Target measurement parameters

"Measure ejecta particle speed (from 0.1-4.8 km/s), mass (10-6 - 102 g), direction, and frequency."

NASA's own spreadsheet stores the mass range as plain text, "10-6 - 102 g": cell H16 of the sheet "Rev C Data Gaps" has no superscript formatting (the file was opened on 2026-10-01) (Data gaps spreadsheet, DN-015 L). ADD Rev C's table prints the range the same way, and no superscripts are visible on the rendered page (p. 279, PDF checked). Reading it as 10⁻⁶ to 10² g is the wiki's inference: no source prints the exponents. So the range stays as printed (open questions, item 20).

Current state of data

"An Apollo-era detector (LEAM) was flown to measure this for very small particles but did not conclusively detect impacts."

Impact if data is unavailable

"Potential damage to landers, rovers, habitats, suits, etc. from unaccounted for ejecta fluxes. Primary meteoroids may directly damage surfaces assets, but the associated ejected material will be more abundant (though at lower velocities)."

Benefits if data is available

"While this data has been modelled, in-situ measurements will help constraint the actual ejecta environment to better assess the risk these projectiles pose to surface assets. The mass/speed distribution may also differ at the South Pole compared to the equator due to different impactor populations, so having datasets for the lunar south pole would be invaluable."

Traceability

  • Objectives: AS-01 LM, LI-09 L, TH-03 L (codes as printed; the sheet gives no titles)
  • Segment: Human Lunar Return (HLR): "The M2M segment during which the data is needed, but not necessarily when it is collected" (Data gaps spreadsheet, Key sheet). A segment is not a Moon Base phase.

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-015 L for one challenge (Users Guide, p. 12):

  • "Operating on the Lunar Surface for Long Durations" (headline challenge). Its knowledge challenge has two sentences: "Characterize the lunar surface environment to predict performance impacts and risks associated with long duration surface operations." and "Investigate dust mechanics, regolith geotechnical properties, and radiation/charged particle fluctuations, seasonal patterns, and scattering." The guide lists DN-008 L to DN-013 L, DN-015 L, DN-016 L and DN-019 L under both sentences together and does not say which sentence each serves. The challenge's technology half cites tech gaps #0101, #0201, #0301, #0801 and #0804.

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.

A Moon Base payload with no phase, a nearby subject (the wiki's link): LEMS-SP, selected through PRISM in September 2026, will monitor "falling micrometeoroids" (PRISM release, "LEMS-SP"). This gap asks for the ejecta that impacts throw up, not the incoming particles, so the fit is partial.

Sources

Data gaps spreadsheet, DN-015 L · Users Guide, pp. 11–12 · ADD Rev C, p. 279