{
  "spore": "profile",
  "id": "nu-lht-2m",
  "spore_version": "0.2",
  "family": "regolith",
  "name": "NU-LHT-2M lunar highlands simulant",
  "abbreviation": "NU-LHT-2M",
  "role": "Ground test stand-in for lunar highlands regolith (Apollo 16 type)",
  "category": "regolith",
  "type": "lunar-simulants",
  "summary": "NU-LHT-2M is a lunar highlands regolith simulant made by NASA and the USGS from Stillwater anorthosite and norite, with synthetic pseudo-agglutinate and good glass. It was designed to match the average composition, particle size and particle shape of Apollo 16 sample 64001/64002. NASA's 2024 user guide lists it as the prototype version of the NU-LHT series and says only very small amounts remain for NASA testing.\n",
  "best_for": "Ground tests of excavation, drilling and abrasion, and oxygen-extraction feedstock for highlands composition (2010 NASA guide)",
  "weakest_at": "Cohesion and friction angle are not reported for NU-LHT-2M (n/a in the 2024 guide), and supply is nearly exhausted",
  "identity": {
    "formula": "Highlands simulant made of crystalline Stillwater anorthosite and norite (65%), pseudo-agglutinate (30%) and good glass (5%) by design, with minor synthetic whitlockite, fluorapatite and pyrite (troilite substitute)",
    "designations": [],
    "source": "nasa-tm-2024-guide",
    "where": "Section 3, page 20 (mixing ratio and minor minerals); page 19 (feedstock)"
  },
  "tags": {
    "environments": [],
    "stresses": [
      "dust-abrasion"
    ],
    "applications": [
      "rovers-and-surface-systems",
      "habitats-and-suits",
      "propulsion-and-tanks"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Bulk density range, NU-LHT-2M (minimum to maximum)",
      "value": 1.37,
      "value_high": 2.06,
      "bound": "range",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "material": "NU-LHT-2M lunar highlands simulant",
        "basis": "rho(min) and rho(max) as printed; the table does not state compaction or moisture"
      },
      "method": "Averaged rho(min) and rho(max) values printed in the table, citing Zeng et al. 2010",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 16, Lunar Simulant Density Values, NU-LHT-2M row",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "density",
      "label": "Bulk density range, Apollo 16 regolith (first of two rows in the table)",
      "value": 1.4,
      "value_high": 1.8,
      "bound": "range",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "material": "Apollo 16 lunar regolith (reference, not a simulant)",
        "basis": "rho(min) and rho(max) as printed"
      },
      "method": "Printed range for Apollo 16, cited to Mitchell et al. 1972b and Carrier 1974",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 15, Lunar Regolith Density values, Apollo 16 first row",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "density",
      "label": "Bulk density range, Apollo 16 regolith (second row in the table, disagrees with the first)",
      "value": 1.47,
      "value_high": 1.75,
      "bound": "range",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "material": "Apollo 16 lunar regolith (reference, not a simulant)",
        "basis": "rho(min) and rho(max) as printed"
      },
      "method": "Printed range for Apollo 16, cited to Carrier 1974",
      "status": "ground",
      "note": "The two Apollo 16 rows in the table give different ranges; both are kept.",
      "source": "nasa-tm-2024-guide",
      "where": "Table 15, Lunar Regolith Density values, Apollo 16 second row",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "particle_size_q25",
      "label": "Particle size, 25th percentile (Q25), NU-LHT-2M",
      "value": 55.9,
      "bound": "exact",
      "unit": "µm",
      "scope": "material",
      "conditions": {
        "quartile": "Q25",
        "basis": "average QN of the simulant PSD as printed",
        "material": "NU-LHT-2M"
      },
      "method": "Average Q25 printed in the table; the text below the table credits Clark 2021 (JSC-ARES) with laser diffraction (ISO 13320-1)",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 10, NU-LHT-2M row, Q25 column; method text below Table 10",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "particle_size_q50",
      "label": "Particle size, median (Q50), NU-LHT-2M",
      "value": 125.7,
      "bound": "exact",
      "unit": "µm",
      "scope": "material",
      "conditions": {
        "quartile": "Q50",
        "basis": "average QN of the simulant PSD as printed",
        "material": "NU-LHT-2M"
      },
      "method": "Average Q50 printed in the table; the text below the table credits Clark 2021 (JSC-ARES) with laser diffraction (ISO 13320-1)",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 10, NU-LHT-2M row, Q50 column; method text below Table 10",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "particle_size_q75",
      "label": "Particle size, 75th percentile (Q75), NU-LHT-2M",
      "value": 244.5,
      "bound": "exact",
      "unit": "µm",
      "scope": "material",
      "conditions": {
        "quartile": "Q75",
        "basis": "average QN of the simulant PSD as printed",
        "material": "NU-LHT-2M"
      },
      "method": "Average Q75 printed in the table; the text below the table credits Clark 2021 (JSC-ARES) with laser diffraction (ISO 13320-1)",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 10, NU-LHT-2M row, Q75 column; method text below Table 10",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "aspect_ratio",
      "label": "Aspect ratio of bulk particle geometry, NU-LHT-2M",
      "value": 0.63,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "material": "NU-LHT-2M",
        "basis": "bulk particle geometry value as printed (dimensionless)"
      },
      "method": "Value printed in the table, citing SDL 2022 (JSC-ARES)",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 13, Lunar regolith simulant particle geometry, NU-LHT-2M row, AR column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "root_form_factor",
      "label": "Root form factor (square root of FF), NU-LHT-2M",
      "value": 0.91,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "material": "NU-LHT-2M",
        "basis": "bulk particle geometry value as printed (dimensionless)"
      },
      "method": "Value printed in the table, citing SDL 2022 (JSC-ARES)",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 13, Lunar regolith simulant particle geometry, NU-LHT-2M row, root form factor column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "crystalline_silica_total",
      "label": "Total crystalline silica, NU-LHT-2M (DCM Science Laboratories, 2023)",
      "value": 0.67,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "total crystalline silica as defined in the table footnote: quartz plus cristobalite plus tridymite",
        "analysis_lab": "DCM Science Laboratories (footnote symbol section mark)"
      },
      "method": "Analysis printed in Table 25; footnote defines the total",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 25, Summary of Total Percent Crystalline and Respirable Silica, NU-LHT-2M row, first entry",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "crystalline_silica_total",
      "label": "Total crystalline silica, NU-LHT-2M (Herndon Solutions Group, 2021)",
      "value": 0.82,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "total crystalline silica as defined in the table footnote",
        "analysis_lab": "Herndon Solutions Group (footnote double dagger)"
      },
      "method": "Analysis printed in Table 25; no respirable value given for this analysis",
      "status": "ground",
      "note": "Disagrees with the 0.67 wt% DCM value above; both are kept.",
      "source": "nasa-tm-2024-guide",
      "where": "Table 25, NU-LHT-2M row, second entry",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "crystalline_silica_respirable",
      "label": "Respirable crystalline silica, NU-LHT-2M (DCM Science Laboratories, 2023)",
      "value": 0.07,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "crystalline silica in the respirable fraction (below 10 µm), removed by wet sieving through a 10 µm sieve",
        "analysis_lab": "DCM Science Laboratories"
      },
      "method": "Analysis printed in Table 25",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 25, NU-LHT-2M row, Total Respirable Crystalline Silica column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "fraction_below_10um",
      "label": "Percent passing below 10 µm (respirable fraction), NU-LHT-2M",
      "value": 10.1,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "percent passing the 10 µm sieve, DCM analysis only",
        "analysis_lab": "DCM Science Laboratories"
      },
      "method": "Value printed in Table 25",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 25, NU-LHT-2M row, Percent Passing (below 10 µm) column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "bulk_sio2",
      "label": "Bulk SiO2, NU-LHT-2M",
      "value": 47,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "bulk oxide chemistry as printed, wt.%",
        "material": "NU-LHT-2M"
      },
      "method": "Oxide analysis printed in the table, cited to Wilson USGS 2020",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 7, Lunar Simulant Bulk Chemistry, NU-LHT-2M row, SiO2 column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "bulk_tio2",
      "label": "Bulk TiO2, NU-LHT-2M",
      "value": 0.4,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "bulk oxide chemistry as printed, wt.%",
        "material": "NU-LHT-2M"
      },
      "method": "Oxide analysis printed in the table, cited to Wilson USGS 2020",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 7, Lunar Simulant Bulk Chemistry, NU-LHT-2M row, TiO2 column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "bulk_al2o3",
      "label": "Bulk Al2O3, NU-LHT-2M",
      "value": 24.5,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "bulk oxide chemistry as printed, wt.%",
        "material": "NU-LHT-2M"
      },
      "method": "Oxide analysis printed in the table, cited to Wilson USGS 2020",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 7, Lunar Simulant Bulk Chemistry, NU-LHT-2M row, Al2O3 column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "bulk_feo",
      "label": "Bulk FeO, NU-LHT-2M",
      "value": 3.7,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "bulk oxide chemistry as printed, wt.%",
        "material": "NU-LHT-2M"
      },
      "method": "Oxide analysis printed in the table, cited to Wilson USGS 2020",
      "status": "ground",
      "note": "The 2010 guide describes NU-LHT-2M as slightly low in FeO against a lunar reference of about 5 wt.% (Table 8 text); the 2024 Apollo highlands average is 6.6 wt.% (Table 6). Both references are recorded in the story.",
      "source": "nasa-tm-2024-guide",
      "where": "Table 7, Lunar Simulant Bulk Chemistry, NU-LHT-2M row, FeO column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
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        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "bulk_mgo",
      "label": "Bulk MgO, NU-LHT-2M",
      "value": 8.4,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "bulk oxide chemistry as printed, wt.%",
        "material": "NU-LHT-2M"
      },
      "method": "Oxide analysis printed in the table, cited to Wilson USGS 2020",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 7, Lunar Simulant Bulk Chemistry, NU-LHT-2M row, MgO column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
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        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "bulk_cao",
      "label": "Bulk CaO, NU-LHT-2M",
      "value": 13.6,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "bulk oxide chemistry as printed, wt.%",
        "material": "NU-LHT-2M"
      },
      "method": "Oxide analysis printed in the table, cited to Wilson USGS 2020",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 7, Lunar Simulant Bulk Chemistry, NU-LHT-2M row, CaO column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
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        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "bulk_na2o",
      "label": "Bulk Na2O, NU-LHT-2M",
      "value": 1.5,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "bulk oxide chemistry as printed, wt.%",
        "material": "NU-LHT-2M"
      },
      "method": "Oxide analysis printed in the table, cited to Wilson USGS 2020",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 7, Lunar Simulant Bulk Chemistry, NU-LHT-2M row, Na2O column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
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        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "bulk_k2o",
      "label": "Bulk K2O, NU-LHT-2M",
      "value": 0.1,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "bulk oxide chemistry as printed, wt.%",
        "material": "NU-LHT-2M"
      },
      "method": "Oxide analysis printed in the table, cited to Wilson USGS 2020",
      "status": "ground",
      "source": "nasa-tm-2024-guide",
      "where": "Table 7, Lunar Simulant Bulk Chemistry, NU-LHT-2M row, K2O column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "plagioclase_modal",
      "label": "Plagioclase, particle-type modal share, NU-LHT-2M",
      "value": 54.9,
      "bound": "exact",
      "unit": "modal %",
      "scope": "material",
      "conditions": {
        "basis": "particle-type modal data from electron beam (QEMSCAN) analysis; the table prints no unit and the figure axis reads Modal (%)",
        "material": "NU-LHT-2M"
      },
      "method": "Value printed in Table 2 (particle type modal data)",
      "status": "ground",
      "source": "nasa-tm-2010-216446",
      "where": "Table 2, particle type modal data, NU-LHT-2M column, Plagioclase row",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide (NASA/TM-2010-216446)",
        "id": "NASA/TM-2010-216446, September 2010",
        "url": "https://ntrs.nasa.gov/api/citations/20100038451/downloads/20100038451.pdf",
        "year": 2010,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "glass_modal",
      "label": "Glass, particle-type modal share, NU-LHT-2M",
      "value": 7.2,
      "bound": "exact",
      "unit": "modal %",
      "scope": "material",
      "conditions": {
        "basis": "particle-type modal data from electron beam (QEMSCAN) analysis; the table prints no unit and the figure axis reads Modal (%)",
        "material": "NU-LHT-2M"
      },
      "method": "Value printed in Table 2 (particle type modal data)",
      "status": "ground",
      "source": "nasa-tm-2010-216446",
      "where": "Table 2, particle type modal data, NU-LHT-2M column, Glass row",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide (NASA/TM-2010-216446)",
        "id": "NASA/TM-2010-216446, September 2010",
        "url": "https://ntrs.nasa.gov/api/citations/20100038451/downloads/20100038451.pdf",
        "year": 2010,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "agglutinate_modal",
      "label": "Agglutinates, particle-type modal share, NU-LHT-2M (2010 guide)",
      "value": 23.5,
      "bound": "exact",
      "unit": "modal %",
      "scope": "material",
      "conditions": {
        "basis": "particle-type modal data from electron beam (QEMSCAN) analysis; the table prints no unit and the figure axis reads Modal (%)",
        "material": "NU-LHT-2M"
      },
      "method": "Value printed in Table 2 (particle type modal data)",
      "status": "ground",
      "note": "The 2024 guide gives 29.02 wt.% agglutinate for the same simulant (below); the two values differ and are not reconciled in either source.",
      "source": "nasa-tm-2010-216446",
      "where": "Table 2, particle type modal data, NU-LHT-2M column, Agglutinates row",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide (NASA/TM-2010-216446)",
        "id": "NASA/TM-2010-216446, September 2010",
        "url": "https://ntrs.nasa.gov/api/citations/20100038451/downloads/20100038451.pdf",
        "year": 2010,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "agglutinate_wt",
      "label": "Agglutinates, NU-LHT-2M (2024 guide, wt.%)",
      "value": 29.02,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "modal mineralogy by mineral group as printed, wt.%",
        "material": "NU-LHT-2M"
      },
      "method": "Value printed in Table 5, modal mineralogy by FoM mineral group",
      "status": "ground",
      "note": "The 2010 guide gives 23.5 modal % for the same simulant; the two values differ and are both kept.",
      "source": "nasa-tm-2024-guide",
      "where": "Table 5, Lunar regolith simulant modal mineralogy (wt.%), NU-LHT-2M row, Agglutinates column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
        "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
        "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
        "year": 2024,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "olivine_modal",
      "label": "Olivine, particle-type modal share, NU-LHT-2M",
      "value": 9.5,
      "bound": "exact",
      "unit": "modal %",
      "scope": "material",
      "conditions": {
        "basis": "particle-type modal data from electron beam (QEMSCAN) analysis; the table prints no unit and the figure axis reads Modal (%)",
        "material": "NU-LHT-2M"
      },
      "method": "Value printed in Table 2 (particle type modal data)",
      "status": "ground",
      "source": "nasa-tm-2010-216446",
      "where": "Table 2, particle type modal data, NU-LHT-2M column, Olivine row",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide (NASA/TM-2010-216446)",
        "id": "NASA/TM-2010-216446, September 2010",
        "url": "https://ntrs.nasa.gov/api/citations/20100038451/downloads/20100038451.pdf",
        "year": 2010,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "clinopyroxene_modal",
      "label": "Clinopyroxene, particle-type modal share, NU-LHT-2M",
      "value": 4,
      "bound": "exact",
      "unit": "modal %",
      "scope": "material",
      "conditions": {
        "basis": "particle-type modal data from electron beam (QEMSCAN) analysis; the table prints no unit and the figure axis reads Modal (%)",
        "material": "NU-LHT-2M"
      },
      "method": "Value printed in Table 2 (particle type modal data)",
      "status": "ground",
      "source": "nasa-tm-2010-216446",
      "where": "Table 2, particle type modal data, NU-LHT-2M column, Clinopyroxene row",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide (NASA/TM-2010-216446)",
        "id": "NASA/TM-2010-216446, September 2010",
        "url": "https://ntrs.nasa.gov/api/citations/20100038451/downloads/20100038451.pdf",
        "year": 2010,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "plagioclase_anorthite",
      "label": "Plagioclase anorthite content, NU-LHT-2M",
      "value": 80,
      "bound": "exact",
      "unit": "An%",
      "scope": "material",
      "conditions": {
        "basis": "molar percent anorthite end-member of plagioclase, as printed in the row labelled Plag. An%",
        "material": "NU-LHT-2M",
        "reference": "Apollo 64001/64002 reference is 95 An% in the same table"
      },
      "method": "Value printed in Table 2, Plag. An% row",
      "status": "ground",
      "source": "nasa-tm-2010-216446",
      "where": "Table 2, (Plag. An%) row, NU-LHT-2M column",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide (NASA/TM-2010-216446)",
        "id": "NASA/TM-2010-216446, September 2010",
        "url": "https://ntrs.nasa.gov/api/citations/20100038451/downloads/20100038451.pdf",
        "year": 2010,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "particle_shape_rounded",
      "label": "Rounded particles, QEMSCAN shape class share, NU-LHT-2M",
      "value": 52.8,
      "bound": "exact",
      "unit": "wt%",
      "scope": "material",
      "conditions": {
        "basis": "QEMSCAN shape classes by weight percent of geologic classification bins",
        "material": "NU-LHT-2M"
      },
      "method": "Value printed in Table 6, shape parameters derived by QEMSCAN",
      "status": "ground",
      "source": "nasa-tm-2010-216446",
      "where": "Table 6, Shape parameters of simulants, NU-LHT-2M column, Rounded row",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide (NASA/TM-2010-216446)",
        "id": "NASA/TM-2010-216446, September 2010",
        "url": "https://ntrs.nasa.gov/api/citations/20100038451/downloads/20100038451.pdf",
        "year": 2010,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "fom_composition_score",
      "label": "Figure of Merit, composition, NU-LHT-2M against lunar reference 64001/64002",
      "value": 0.55,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "basis": "FoM Revision 1 composition algorithm against reference 64001/64002, score as printed"
      },
      "method": "Score printed in Table 3, FoM composition analysis",
      "status": "ground",
      "source": "nasa-tm-2010-216446",
      "where": "Table 3, Results of FoM composition analysis, NU-LHT-2M row",
      "source_detail": {
        "title": "Lunar Regolith Simulant User's Guide (NASA/TM-2010-216446)",
        "id": "NASA/TM-2010-216446, September 2010",
        "url": "https://ntrs.nasa.gov/api/citations/20100038451/downloads/20100038451.pdf",
        "year": 2010,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "specific_gravity",
      "label": "Specific gravity, NU-LHT-2M (NASA JSC ARES geomechanical table)",
      "value": 2.749,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "material": "NU-LHT-2M",
        "basis": "specific gravity as printed in the ARES table, with its reference [2] (Zeng et al. 2010)"
      },
      "method": "Value printed in the ARES Geomechanical Properties table for NU-LHT-2M, citing Zeng et al. (2010), Journal of Aerospace Engineering 23(4), 213-218",
      "status": "ground",
      "source": "nasa-ares-nu-lht",
      "where": "Geomechanical Properties for NU-LHT-2M table, Specific Gravity column",
      "source_detail": {
        "title": "NU-LHT simulant page, NASA JSC Astromaterials Research and Exploration Science (ARES), with Geomechanical Properties table",
        "id": "NASA JSC ARES simulants page for NU-LHT; geomechanical table cites Zeng et al. (2010)",
        "url": "https://ares.jsc.nasa.gov/projects/simulants/nu-lht.html",
        "kind": "web",
        "license": "NASA website (cited, not reproduced)"
      }
    },
    {
      "benchmark": "density",
      "label": "Bulk density range, NU-LHT-2M (NASA JSC ARES geomechanical table)",
      "value": 1.648,
      "value_high": 1.869,
      "bound": "range",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "material": "NU-LHT-2M",
        "basis": "bulk density range as printed in the ARES table, with its reference [2] (Zeng et al. 2010)"
      },
      "method": "Range printed in the ARES Geomechanical Properties table, citing Zeng et al. (2010)",
      "status": "ground",
      "note": "The 2024 guide Table 16 gives a different range for the same simulant (1.37 to 2.06 g/cm3, above); both are kept.",
      "source": "nasa-ares-nu-lht",
      "where": "Geomechanical Properties for NU-LHT-2M table, Density (g/cm 3) Bulk row",
      "source_detail": {
        "title": "NU-LHT simulant page, NASA JSC Astromaterials Research and Exploration Science (ARES), with Geomechanical Properties table",
        "id": "NASA JSC ARES simulants page for NU-LHT; geomechanical table cites Zeng et al. (2010)",
        "url": "https://ares.jsc.nasa.gov/projects/simulants/nu-lht.html",
        "kind": "web",
        "license": "NASA website (cited, not reproduced)"
      }
    },
    {
      "benchmark": "void_ratio",
      "label": "Void ratio range, NU-LHT-2M (NASA JSC ARES geomechanical table)",
      "value": 0.332,
      "value_high": 1.004,
      "bound": "range",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "material": "NU-LHT-2M",
        "basis": "dimensionless void ratio range as printed in the ARES table, with its reference [2]"
      },
      "method": "Range printed in the ARES Geomechanical Properties table, citing Zeng et al. (2010)",
      "status": "ground",
      "source": "nasa-ares-nu-lht",
      "where": "Geomechanical Properties for NU-LHT-2M table, Void Ratio row",
      "source_detail": {
        "title": "NU-LHT simulant page, NASA JSC Astromaterials Research and Exploration Science (ARES), with Geomechanical Properties table",
        "id": "NASA JSC ARES simulants page for NU-LHT; geomechanical table cites Zeng et al. (2010)",
        "url": "https://ares.jsc.nasa.gov/projects/simulants/nu-lht.html",
        "kind": "web",
        "license": "NASA website (cited, not reproduced)"
      }
    },
    {
      "benchmark": "friction_angle",
      "label": "Triaxial friction angle, NU-LHT-2M (NASA JSC ARES geomechanical table)",
      "value": 36,
      "value_high": 40.7,
      "bound": "range",
      "unit": "°",
      "scope": "material",
      "conditions": {
        "material": "NU-LHT-2M",
        "basis": "triaxial shear strength, friction angle as printed in the ARES table; the same table gives no cohesion value for this simulant"
      },
      "method": "Range printed in the ARES Geomechanical Properties table, citing Zeng et al. (2010)",
      "status": "ground",
      "note": "The 2024 guide Table 19 prints n/a for NU-LHT-2M cohesion and friction angle; the ARES page gives a value and the 2024 guide does not, so both are kept.",
      "source": "nasa-ares-nu-lht",
      "where": "Geomechanical Properties for NU-LHT-2M table, Triaxial Shear Strength, Friction Angle column",
      "source_detail": {
        "title": "NU-LHT simulant page, NASA JSC Astromaterials Research and Exploration Science (ARES), with Geomechanical Properties table",
        "id": "NASA JSC ARES simulants page for NU-LHT; geomechanical table cites Zeng et al. (2010)",
        "url": "https://ares.jsc.nasa.gov/projects/simulants/nu-lht.html",
        "kind": "web",
        "license": "NASA website (cited, not reproduced)"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Moist air during storage and transport",
      "headline": "Simulant takes up water from moist air and can weather over time, so the 2024 guide says to store it away from moist air.",
      "effect": "The 2024 guide says simulant materials must be stored to minimise or eliminate contact with moist air, to avoid water intake and possible weathering over time. It also says all simulants show some hygroscopicity and that available simulants are often contaminated with adsorbed water and humid air from transportation and previous testing. This is a general statement for simulants; no NU-LHT-2M-specific water-uptake value was found in the sections read.",
      "rating": "moderate",
      "conditions": {
        "basis": "general statement for lunar regolith simulants; the rating is the assistant's judgment, as the guide gives none",
        "exposure": "storage and transport; no humidity level or time given"
      },
      "source": "nasa-tm-2024-guide",
      "where": "Section 6.3 (storage paragraph); Section 6.3.1 (Desiccation); Section 6.2.1.B.(i) (Low Temperatures, adsorbed water)"
    },
    {
      "environment": "Size segregation during storage and transport (physical change)",
      "headline": "Stored simulant segregates by size, so the particle size distribution changes unless the container is mixed before sampling.",
      "effect": "The 2024 guide says the particle size distribution does not stay the same during transport and storage, because larger, more buoyant particles migrate upward when vibrated. It recommends homogenising stored simulant by rolling and overturning the containers before sampling, and measuring the size distribution of used simulant before reuse.",
      "rating": "moderate",
      "conditions": {
        "basis": "general statement for stored lunar regolith simulants; the rating is the assistant's judgment, as the guide gives none",
        "process": "transport and storage in containers with vibration"
      },
      "source": "nasa-tm-2024-guide",
      "where": "Section 6.3 (paragraph on size segregation)"
    },
    {
      "environment": "High-temperature processing in ambient air (oxidation)",
      "headline": "Processing simulant at high temperature in ambient air can form oxidation products that would not form under lunar conditions.",
      "effect": "The 2024 guide says high-temperature processing of regolith in ambient conditions increases the potential of forming oxidation products that would not be formed under lunar conditions. It says oxidation can involve minor components that change yields or form unwanted by-products, and it advises an inert atmosphere for ambient-pressure processing tests.",
      "rating": "moderate",
      "conditions": {
        "basis": "general statement for lunar regolith simulants; the guide gives no temperature for this statement; the rating is the assistant's judgment",
        "atmosphere": "ambient air"
      },
      "source": "nasa-tm-2024-guide",
      "where": "Section 6.2.1.B.(ii) (High Temperatures)"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Crystalline silica is the main health concern for people using the simulant. The guide names quartz, cristobalite and tridymite, and says chronic inhalation of respirable particles below 10 microns can lead to pneumoconiosis, including silicosis.",
        "ghs": [],
        "source": "nasa-tm-2024-guide",
        "where": "Section 5.5.2 (Illness)"
      },
      {
        "text": "Table 25 gives NU-LHT-2M 0.67 wt.% total crystalline silica and 0.07 wt.% respirable crystalline silica (DCM 2023). The guide says crystalline silica is regulated under OSHA general industry and construction standards.",
        "ghs": [],
        "source": "nasa-tm-2024-guide",
        "where": "Table 25, NU-LHT-2M row; Section 5.5.2"
      },
      {
        "text": "PubChem's GHS record for cristobalite (ECHA notifications, EC 238-455-4), a crystalline silica phase the 2024 guide names, gives H350 'May cause cancer' (12.6% of notifications) and H372 'Causes damage to organs through prolonged or repeated exposure' (46%), with signal word Danger and pictogram GHS08. The percentages are the share of notifications that reported each code, as printed.",
        "ghs": [
          "H350",
          "H372"
        ],
        "source": "pubchem-silica-ghs",
        "where": "Safety and Hazards, GHS Classification (CID 24261), ECHA entry for Cristobalite (EC 238-455-4)"
      },
      {
        "text": "OSHA says respirable crystalline silica can cause silicosis, lung cancer, chronic obstructive pulmonary disease (COPD) and kidney disease, and that dust is created when stone, rock, concrete, brick and mortar are cut, sawed, ground, drilled or crushed.",
        "ghs": [],
        "source": "osha-silica-page",
        "where": "Crystalline silica topic page, health effects and dust-creation text"
      }
    ],
    "failure_risks": [
      {
        "mode": "Airborne particles and soil movement during vacuum pump-down",
        "trigger": "Pumping down a simulant bed in a vacuum chamber, where adsorbed water comes off the particles",
        "consequence": "The 2024 guide says simulant off-gasses violently during pump-down, that particulate matter poses a risk to chamber hardware (pumps and instruments), and that soil movement can make spouts of airborne particles that disturb the bed. Regulating the pump rate to keep pressure decay slow reduces the disturbance.",
        "severity": "moderate",
        "source": "nasa-tm-2024-guide",
        "where": "Section 6.2.2.A.(i) (Dry Regolith Tests)"
      },
      {
        "mode": "Moisture carried into a test from storage or earlier use",
        "trigger": "Simulant used without drying after transport or earlier testing",
        "consequence": "Simulants are often contaminated with adsorbed water and humid air, which changes the starting state of a test. The guide recommends thorough drying before emplacement in the test environment; chamber evacuation removes some moisture, but ambient desiccation is limited.",
        "severity": "moderate",
        "source": "nasa-tm-2024-guide",
        "where": "Section 6.2.1.B.(i) (Low Temperatures); Section 6.2.2.A.(i) (Dry Regolith Tests)"
      }
    ],
    "side_effects": [
      {
        "text": "The 2010 guide says the phosphates and sulfides in NU-LHT-2M are realistic but possibly hazardous to ISRU processes; the table does not say how.",
        "affects": "ISRU oxygen-extraction processes that heat or reduce the feedstock",
        "source": "nasa-tm-2010-216446",
        "where": "Table 8, Oxygen Production column, NU-LHT-2M row"
      }
    ],
    "handling": [
      {
        "text": "The 2024 guide says eye protection, glasses or goggles, is needed depending on the simulant's physical characteristics.",
        "source": "nasa-tm-2024-guide",
        "where": "Section 5.5, text before 5.5.2"
      },
      {
        "text": "Crystalline silica can become airborne when workers chip, cut, drill or grind objects that contain silica.",
        "source": "nasa-tm-2024-guide",
        "where": "Section 5.5.2 (Illness)"
      },
      {
        "text": "OSHA's respirable crystalline silica standard sets the permissible exposure limit at no exposure 'in excess of 50 μg/m3, calculated as an 8-hour TWA' (29 CFR 1910.1053(c)), with an action level of 25 μg/m3 calculated as an 8-hour TWA (29 CFR 1910.1053(b)).",
        "source": "osha-1910-1053",
        "where": "29 CFR 1910.1053, paragraphs (b) and (c)"
      }
    ],
    "mitigations": [
      {
        "text": "The 2024 guide says simulant used in ambient-condition mechanical testing should be stored dry in a location with active humidity control; if that is not possible, it should be desiccated first using the Section 6.3.1 methods.",
        "source": "nasa-tm-2024-guide",
        "where": "Section 6.2.1 key recommendations (ambient condition mechanical testing); Section 6.3.1 (Desiccation)"
      }
    ]
  },
  "uses": [
    {
      "application": "rovers-and-surface-systems",
      "device": "Excavation and flow testing",
      "example": "The 2010 guide rates NU-LHT-2M recommended for excavation and flow, because pseudo-agglutinates affect geomechanical behavior that may be important to excavation.",
      "source": "nasa-tm-2010-216446",
      "where": "Table 7, fit-to-use matrix, Excavation/Flow column, NU-LHT-2M row"
    },
    {
      "application": "rovers-and-surface-systems",
      "device": "Drilling and abrasion or wear testing",
      "example": "The 2010 guide rates NU-LHT-2M recommended for drilling and abrasion, because fidelity to mineral and glass percentages should yield appropriate abrasiveness.",
      "source": "nasa-tm-2010-216446",
      "where": "Table 7, fit-to-use matrix, Drilling and Abrasion/Wear columns, NU-LHT-2M row"
    },
    {
      "application": "propulsion-and-tanks",
      "device": "Oxygen production feedstock for in-situ resource utilization tests",
      "example": "The 2010 guide rates NU-LHT-2M most recommended for highlands oxygen production, with slightly low FeO against the lunar reference (about 4 against 5 wt.%); it also says the high iron in silicates will slow reduction.",
      "source": "nasa-tm-2010-216446",
      "where": "Table 8, Oxygen Production column, NU-LHT-2M row"
    },
    {
      "application": "habitats-and-suits",
      "device": "Human health and dust studies",
      "example": "The 2010 guide rates NU-LHT-2M the most suitable composition for human health studies, with a reasonable PSD that is too coarse in the fine fraction.",
      "source": "nasa-tm-2010-216446",
      "where": "Table 8, Human Health Studies column, NU-LHT-2M row"
    }
  ],
  "supply": [
    {
      "subject": "NU-LHT-2M simulant (USGS and NASA)",
      "abundance": "not stated in the three sources",
      "producers": [],
      "critical_lists": [],
      "recycling": "not stated in the three sources",
      "substitutes": [],
      "source": "nasa-tm-2024-guide",
      "where": "Table 2 (producer USGS/NASA, footnote ** says these entities no longer manufacture the simulant); Section 3.4 (only very small amounts still exist for NASA testing); Section 3.5 (NU-LHT supply was about spent)"
    },
    {
      "subject": "Feldspar, the mineral class of the anorthosite feedstock (USGS feldspar chapter; not NU-LHT-2M itself)",
      "abundance": "not stated in the USGS feldspar chapter",
      "producers": [
        {
          "country": "India",
          "share_percent": 19.4,
          "year": 2025
        },
        {
          "country": "Turkey",
          "share_percent": 17.1,
          "year": 2025
        },
        {
          "country": "Iran",
          "share_percent": 12.6,
          "year": 2025
        },
        {
          "country": "China",
          "share_percent": 11.9,
          "year": 2025
        },
        {
          "country": "Italy",
          "share_percent": 7.1,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS feldspar chapter: feldspar and nepheline syenite are not recycled by producers; glass container producers use cullet, which reduces feldspar consumption.",
      "substitutes": [
        "USGS: feldspar can be replaced in some end uses by clays, electric furnace slag, feldspar-silica mixtures, pyrophyllite, spodumene, or talc."
      ],
      "source": "usgs-mcs2026-feldspar",
      "where": "World Mine Production and Reserves table, mine production 2025 (world total 31,000 thousand t, rounded; shares calculated by Space Mushroom against that total); Recycling; Substitutes"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "NASA/TM-2010-216446, Lunar Regolith Simulant User's Guide (Schrader et al., September 2010)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/api/citations/20100038451/downloads/20100038451.pdf",
      "year": 2010
    },
    {
      "title": "NASA/TM-20240011783, Lunar Regolith Simulant User's Guide, Revision A (Slabic et al., effective 10/24/2024)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
      "year": 2024
    },
    {
      "title": "NASA Lunar Regolith Simulant Program (Edmunson et al., 3-page abstract)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/api/citations/20100017474/downloads/20100017474.pdf",
      "year": 2010
    },
    {
      "title": "NASA JSC ARES, NU-LHT simulant page with Geomechanical Properties table",
      "type": "report",
      "url": "https://ares.jsc.nasa.gov/projects/simulants/nu-lht.html"
    },
    {
      "title": "Mineral Commodity Summaries 2026, Feldspar and Nepheline Syenite (USGS)",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-feldspar.pdf",
      "year": 2026
    },
    {
      "title": "PubChem, Silica (CID 24261), Safety and Hazards, GHS Classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/24261/JSON?heading=GHS+Classification"
    },
    {
      "title": "OSHA, Crystalline Silica topic page",
      "type": "report",
      "url": "https://www.osha.gov/silica-crystalline"
    },
    {
      "title": "29 CFR 1910.1053, Respirable crystalline silica (general industry)",
      "type": "standard",
      "url": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1053"
    },
    {
      "title": "RF Metrology of Lunar Highlands Regolith Simulant NU-LHT-2M (Johnson, Eckman, Swank, Zemba, 2023)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/citations/20230013296",
      "year": 2023
    }
  ],
  "gaps": [
    "No NU-LHT-2M-specific corrosion or moisture-uptake value was found. The ageing entries are the 2024 guide's general statements for all simulants, and their ratings (moderate) are the assistant's judgment, as the guide gives none.",
    "Cohesion is not reported for NU-LHT-2M in any source read: the 2024 guide prints n/a (Table 19) and the ARES table shows a dash in the cohesion column.",
    "The friction angle of 36 to 40.7 degrees comes from the ARES page only, which cites Zeng et al. (2010); the 2024 guide prints n/a for it. Both are kept, and the primary Zeng paper was not opened.",
    "No safety data sheet or PubChem GHS record for NU-LHT-2M itself was found. The GHS entry is for cristobalite, a silica phase the 2024 guide names in the simulant; the OSHA entries are its health-effect text.",
    "No control measures beyond eye protection, dust avoidance and dry storage are stated in the sources read.",
    "Supply of NU-LHT-2M: no current producer, stock quantity or price was found. The 2024 guide says the producers no longer manufacture it; the ARES page says the USGS is looking into re-starting its simulant efforts.",
    "Critical-mineral lists (USGS and EU) were not checked for feldspar or the anorthosite feedstock in this run.",
    "The feldspar supply entry covers feldspar mineral production, the mineral class of anorthosite; it is not a supply figure for anorthosite or for NU-LHT-2M.",
    "Modal mineralogy disagrees between the 2010 and 2024 guides (agglutinates 23.5 modal % against 29.02 wt.%); neither source reconciles the two, so both are kept.",
    "The 65, 30 and 5 percent mixing ratio is the design ratio stated in the 2024 guide, not a measured value; the measured modal values are listed as properties.",
    "Magnetic susceptibility (Table 22, log units) and the 2024 figure-of-merit summary scores were not added as properties; the composition FoM from the 2010 guide is included.",
    "The MDPI Aerospace 2024 paper on NU-LHT-2M (Zanotti et al., doi 10.3390/aerospace11040295) returned 403 Access Denied to automated access, so it was not read. The Zeng 2010 and Martin 2022 papers were not opened.",
    "Void ratio, specific gravity and friction angle use snake_case names that are not in spores/property-canon.yaml.",
    "The OSHA permissible exposure limit was read through WebFetch of the OSHA 1910.1053 page, because curl to that page was blocked (403), so the quotation is not from raw page text.",
    "The NASA abstract (NTRS 20100017474) prints no year in the PDF text; the year 2010 is taken from the NTRS identifier."
  ],
  "story": {
    "why": "NU-LHT-2M is a NASA and USGS lunar highlands simulant. It was built to match the average composition, particle size and particle shape of Apollo 16 sample 64001/64002, and it was the prototype version of the NU-LHT series. The 2024 guide says only very small amounts remain for NASA testing.",
    "uses": [
      {
        "where": "Excavation and drilling",
        "line": "The 2010 guide rates NU-LHT-2M recommended for excavation and flow, and recommended for drilling and abrasion testing, because its mineral and glass percentages should give realistic abrasiveness."
      },
      {
        "where": "Oxygen production (in-situ resource utilization)",
        "line": "The 2010 guide rates NU-LHT-2M most recommended for highlands oxygen production, because its FeO is slightly low against the lunar reference (about 4 against 5 wt.%), but it warns that its phosphates and sulfides may be hazardous to ISRU processes."
      },
      {
        "where": "Human health studies",
        "line": "The 2010 guide rates NU-LHT-2M the most suitable composition for human health studies, with a reasonable particle size distribution that is too coarse in the fine fraction."
      }
    ],
    "can_do": [
      {
        "label": "Density",
        "line": "Bulk density ranges from 1.37 to 2.06 g/cm3 for NU-LHT-2M, as printed in the 2024 guide Table 16. The two Apollo 16 regolith rows in Table 15 are listed as separate properties of this profile.",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Particle size",
        "line": "The median particle size (Q50) is 125.7 µm, with Q25 at 55.9 µm and Q75 at 244.5 µm, as printed in Table 10 (Clark 2021).",
        "benchmark": "particle_size_q50",
        "scope": "material"
      },
      {
        "label": "Particle shape",
        "line": "The bulk aspect ratio is 0.63 and the root form factor 0.91 (Table 13, SDL 2022). The 2010 guide's QEMSCAN count gives 52.8 wt.% rounded particles (Table 6).",
        "benchmark": "aspect_ratio",
        "scope": "material"
      },
      {
        "label": "Composition",
        "line": "Bulk SiO2 is 47 wt.% and bulk Al2O3 is 24.5 wt.% (Table 7, Wilson USGS 2020). The composition figure of merit against the Apollo 64001/64002 reference is 0.55 (Table 3, 2010 guide).",
        "benchmark": "bulk_sio2",
        "scope": "material"
      }
    ],
    "compare": "NU-LHT-2M sits at the highlands end of the NU-LHT family. On the 2010 composition figure of merit it scores 0.55 against lunar reference 64001/64002. The same table ranks it above every other simulant listed except NU-LHT-1M, which scores higher (Table 3). Its median particle size is 125.7 µm (Table 10). The two Apollo 16 density rows in Table 15 disagree, and the NU-LHT-2M density range is printed alongside them (Table 16). The reference FeO is also not settled: the 2024 guide gives 6.6 wt.% for the Apollo highlands average (Table 6), while the 2010 guide cites about 5 wt.% for its lunar reference. Cohesion is not reported for this simulant. The NASA JSC ARES page gives a triaxial friction angle of 36 to 40.7 degrees (Zeng et al. 2010), where the 2024 guide prints n/a (Table 19).",
    "compare_rows": [
      {
        "label": "Bulk density range",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Median particle size, Q50",
        "benchmark": "particle_size_q50",
        "scope": "material"
      },
      {
        "label": "Composition figure of merit",
        "benchmark": "fom_composition_score",
        "scope": "material"
      }
    ],
    "handling": [
      "Treat dust as a health concern: the guide reports 0.67 wt.% total crystalline silica and 0.07 wt.% respirable crystalline silica.",
      "Wear eye protection suited to the simulant's physical form, as the 2024 guide advises.",
      "Keep the dust from becoming airborne when cutting, drilling or grinding silica-bearing objects.",
      "Only very small amounts remain for NASA testing, so check availability before planning a test.",
      "Store the simulant dry under active humidity control, or desiccate it first (2024 guide, Section 6.2.1)."
    ],
    "good_for": [
      "Highlands-like composition: bulk SiO2 of 47 wt.% and Al2O3 of 24.5 wt.% (Table 7, Wilson USGS 2020).",
      "Oxygen-production and excavation studies, which the 2010 guide rates recommended for this composition (Tables 7 and 8)."
    ],
    "watch_out": [
      "Cohesion is not reported for NU-LHT-2M, and the 2024 guide prints n/a for its friction angle (Table 19). The ARES page gives 36 to 40.7 degrees, a value the 2024 guide does not reconcile.",
      "Supply is nearly exhausted: the 2024 guide says the producers no longer manufacture this simulant.",
      "Phosphates and sulfides may be hazardous to ISRU processes (Table 8, 2010 guide)."
    ],
    "verdict": "NU-LHT-2M is a well-documented highlands simulant in these three NASA guides, with composition, particle size, shape and density data. Its supply is nearly exhausted and its cohesion is not reported, so new test programmes should check availability first.",
    "recipe": {
      "line": "NU-LHT-2M is a physical mixture, not one compound. Its crystalline part is Stillwater anorthosite and norite with minor synthetic whitlockite, fluorapatite and pyrite. Its pseudo-agglutinate is made from Stillwater mill sand in a plasma arc, and its good glass is a synthetic glass with a highlands-like composition.",
      "parts": [
        {
          "name": "Stillwater anorthosite and norite (crystalline)",
          "role": "The dominant rocks in the mix. Plagioclase, pyroxene and olivine make up the crystalline part, as the 2010 and 2024 modal tables show."
        },
        {
          "name": "Pseudo-agglutinate",
          "role": "Glass-bonded fragments made from Stillwater mill sand in a plasma arc. The 2010 guide counts them as agglutinates."
        },
        {
          "name": "Good glass",
          "role": "Glass with no mineral inclusions, per the 2024 guide."
        },
        {
          "name": "Minor synthetic minerals",
          "role": "Synthetic whitlockite, fluorapatite and pyrite (troilite substitute), included in -2M and not in -1M."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The 2024 guide says the primary exposure concerns for simulant users are crystalline silica and total dust.",
        "points": [
          {
            "label": "Silica content",
            "line": "Table 25 gives 0.67 wt.% total crystalline silica (DCM 2023) and 0.82 wt.% (Herndon 2021) for NU-LHT-2M. The respirable crystalline silica is 0.07 wt.% (DCM 2023)."
          },
          {
            "label": "Illness",
            "line": "The guide says chronic inhalation of respirable particles below 10 microns can lead to pneumoconiosis, including silicosis, after years of exposure."
          },
          {
            "label": "Dust in work",
            "line": "Crystalline silica can become airborne when workers chip, cut, drill or grind objects that contain silica."
          }
        ],
        "level": 0,
        "verdict": "Dust is the concern: silica is present at low levels"
      },
      {
        "title": "In ISRU processing",
        "lead": "The 2010 guide names the phosphates and sulfides as a possible hazard for ISRU processes.",
        "points": [
          {
            "label": "Minerals",
            "line": "Table 8 says the phosphates and sulfides in NU-LHT-2M are realistic but possibly hazardous to ISRU processes. The table does not say how."
          },
          {
            "label": "Oxygen production",
            "line": "Table 8 rates NU-LHT-2M most recommended for highlands oxygen production, with slightly low FeO (about 4 against 5 wt.%). It also says the high iron in its silicates will slow reduction."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Eye protection",
            "line": "The 2024 guide says glasses or goggles are needed depending on the simulant's physical characteristics."
          },
          {
            "label": "Airborne dust",
            "line": "Silica-bearing material becomes airborne when it is chipped, cut, drilled or ground."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 33,
    "unreachable": 0,
    "caveats": 2,
    "note": "Written by an AI assistant from nine sources read in this run (three NASA guides and report pages, the NASA JSC ARES simulant page, the USGS feldspar chapter, PubChem and two OSHA pages). The MDPI open paper returned 403 and was not read. Values are as printed; discrepancies are shown side by side."
  },
  "sources": {
    "nasa-tm-2010-216446": {
      "title": "Lunar Regolith Simulant User's Guide (NASA/TM-2010-216446)",
      "id": "NASA/TM-2010-216446, September 2010",
      "url": "https://ntrs.nasa.gov/api/citations/20100038451/downloads/20100038451.pdf",
      "year": 2010,
      "kind": "report",
      "license": "public domain (NASA)"
    },
    "nasa-tm-2024-guide": {
      "title": "Lunar Regolith Simulant User's Guide, Revision A (NASA/TM-20240011783)",
      "id": "NASA/TM-20240011783, Rev A effective 10/24/2024",
      "url": "https://ntrs.nasa.gov/api/citations/20240011783/downloads/Lunar_Regolith_Simulant_Users_Guide_Rev_A_28OCT.pdf",
      "year": 2024,
      "kind": "report",
      "license": "public domain (NASA)"
    },
    "nasa-lpsc-abstract": {
      "title": "NASA Lunar Regolith Simulant Program (Edmunson et al., 3-page abstract)",
      "id": "NTRS 20100017474 (year not printed in the PDF text)",
      "url": "https://ntrs.nasa.gov/api/citations/20100017474/downloads/20100017474.pdf",
      "year": 2010,
      "kind": "report",
      "license": "public domain (NASA)"
    },
    "nasa-ares-nu-lht": {
      "title": "NU-LHT simulant page, NASA JSC Astromaterials Research and Exploration Science (ARES), with Geomechanical Properties table",
      "id": "NASA JSC ARES simulants page for NU-LHT; geomechanical table cites Zeng et al. (2010)",
      "url": "https://ares.jsc.nasa.gov/projects/simulants/nu-lht.html",
      "kind": "web",
      "license": "NASA website (cited, not reproduced)"
    },
    "usgs-mcs2026-feldspar": {
      "title": "Mineral Commodity Summaries 2026, Feldspar and Nepheline Syenite (USGS)",
      "id": "USGS Mineral Commodity Summaries 2026, feldspar chapter",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-feldspar.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "pubchem-silica-ghs": {
      "title": "PubChem, Silica (CID 24261), Safety and Hazards, GHS Classification (ECHA entries)",
      "id": "PubChem CID 24261; ECHA C&L Inventory entries as shown on PubChem",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/24261/JSON?heading=GHS+Classification",
      "kind": "database",
      "license": "PubChem (NIH), data as shown"
    },
    "osha-silica-page": {
      "title": "OSHA, Crystalline Silica (topic page)",
      "id": "osha.gov/silica-crystalline",
      "url": "https://www.osha.gov/silica-crystalline",
      "kind": "web",
      "license": "public domain (US government)"
    },
    "osha-1910-1053": {
      "title": "29 CFR 1910.1053, Respirable crystalline silica (general industry)",
      "id": "29 CFR 1910.1053",
      "url": "https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1053",
      "kind": "standard",
      "license": "public domain (US government)"
    },
    "johnson2023-ntrs": {
      "title": "RF Metrology of Lunar Highlands Regolith Simulant NU-LHT-2M (Johnson, Eckman, Swank, Zemba, 2023)",
      "id": "NASA NTRS 20230013296",
      "url": "https://ntrs.nasa.gov/citations/20230013296",
      "year": 2023,
      "kind": "report",
      "license": "public domain (NASA)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/nu-lht-2m/"
}