{
  "title": "Endpoint provenance for NASA 2026 small-spacecraft electric-propulsion ranges",
  "review_date": "2026-10-05",
  "survey": {
    "table": "NASA Small Spacecraft Technology State of the Art, 2026 edition, In-Space Propulsion, Table 4-1",
    "url": "https://www.nasa.gov/smallsat-institute/sst-soa/in-space_propulsion/",
    "scope": "A secondary survey of selected small-spacecraft devices. It says the ranges are not universal technology limits; cited performance is generally not independently verified unless noted, and some rows are components rather than complete systems."
  },
  "interpretation": "These six pairs of thrust and specific-impulse minima/maxima are independent extrema across heterogeneous entries. They are not paired operating points, a common test protocol, or guaranteed technology envelopes. Labels below distinguish catalog claims, published tests, flight history, arithmetic reconstruction, and unresolved provenance.",
  "categories": [
    {
      "name": "Electrothermal",
      "survey_range": {
        "thrust_mN": [
          0.1,
          1000
        ],
        "specific_impulse_s": [
          20,
          350
        ]
      },
      "findings": [
        {
          "endpoint": "low thrust / low specific impulse",
          "status": "Survey-table trace to AIS SWAG1-PQ; manufacturer catalog values, not an independently verified test in the traced material.",
          "sources": [
            "https://appliedionsystems.com/products/"
          ]
        },
        {
          "endpoint": "high thrust",
          "status": "The 1 N upper entry is the marketed upper bound of the Benchmark Starling Ardent family (10–1000 mN); this does not establish a demonstrated operating point at 1 N.",
          "sources": [
            "https://www.benchmarkspacesystems.com/hubfs/Data%20Sheets/BSS%20Datasheet%20-%20Starling%20OCT%202023.pdf?hsLang=en"
          ]
        },
        {
          "endpoint": "high specific impulse",
          "status": "The 350 s entry is a manufacturer nominal specification for the EPL APS500, not a universal electrothermal limit.",
          "sources": [
            "https://electricpropulsionlab.com/resistojet-propulsion-systems/"
          ]
        }
      ]
    },
    {
      "name": "Electrospray",
      "survey_range": {
        "thrust_mN": [
          0.02,
          20
        ],
        "specific_impulse_s": [
          225,
          3000
        ]
      },
      "findings": [
        {
          "endpoint": "low thrust / low specific impulse",
          "status": "NASA Table 4-1's 20 μN is the lowest nominal survey value, not a demonstrated minimum operating capability. The NASA 2026 PDF Table 4-8 (printed p. 112 / PDF p. 57) gives Busek CMNT (4x heads), “4 x 20” under a [μN] header. NASA's 2017 flight-performance paper (NTRS 20170010216, pp. 4–5) states that each of four heads in a CMTA is individually throttleable from 5 to 30 μN. This supports reading the 2026 row as four heads at a nominal 20 μN per head; 4 × 20 = 80 μN is the arithmetic total if all four operate at that point, not a measured simultaneous flight condition. The 2017 source establishes operation/capability down to 5 μN per head, so the 20 μN Table 4-1 value is not the CMNT minimum. NASA's current live HTML labels Table 4-8 thrust [mN], conflicting by a factor of 1000 with the downloadable PDF and the flight paper; treat the HTML unit as an apparent label/version error, pending NASA clarification.",
          "sources": [
            "https://www.nasa.gov/wp-content/uploads/2026/05/4-in-space-propulsion-chapter-2026-final.pdf",
            "https://www.nasa.gov/smallsat-institute/sst-soa/in-space_propulsion/",
            "https://science.nasa.gov/science-research/science-enabling-technology/technology-highlights/colloid-microthrusters-demonstrated-on-lisa-pathfinder/"
          ],
          "source_locators": {
            "category_summary": {
              "source": "NASA 2026 downloadable PDF",
              "table": "Table 4-1: Summary of Propulsion Technologies Surveyed",
              "printed_page": 66,
              "pdf_page": 11,
              "thrust_range": "Electrosprays 20 μN–20 mN"
            },
            "device_row_pdf": {
              "source": "NASA 2026 downloadable PDF",
              "table": "Table 4-8: Electrospray Electric Propulsion",
              "printed_page": 112,
              "pdf_page": 57,
              "header": "Thrust [μN]",
              "row": "Busek CMNT (4x heads), 4 x 20"
            },
            "head_performance_primary": {
              "source": "Ziemer et al., NASA NTRS 20170010216, ST7 Colloid Micro-Newton Thruster flight performance",
              "url": "https://ntrs.nasa.gov/api/citations/20170010216/downloads/20170010216.pdf",
              "printed_pages": [
                4,
                5
              ],
              "abstract_locator": "PDF p. 1: eight CMNTs provided 5–30 μN each; flight validation",
              "design_locator": "PDF p. 4: each CMTA has four microthruster heads",
              "throttle_locator": "PDF p. 5: each head individually throttable from 5 to 30 μN",
              "archive_path": "sources/documents-externes/NASA-IEPC-2017-ST7-CMNT-flight-performance.pdf",
              "archive_sha256": "00B82C9010E75132F1EE01DF4C8C34A09CB015B199E76D229D19DFC1C7783132"
            },
            "device_row_html": {
              "source": "NASA live HTML edition, accessed 2026-10-05",
              "url": "https://www.nasa.gov/smallsat-institute/sst-soa/in-space_propulsion/",
              "table": "Table 4-8: Electrospray Electric Propulsion",
              "header": "Thrust [mN]",
              "row": "Busek CMNT (4x heads), 4 x 20"
            }
          }
        },
        {
          "endpoint": "high thrust",
          "status": "20 mN is an Enpulsion Neo catalog entry, not an independently validated class maximum.",
          "sources": [
            "https://www.enpulsion.com/products/"
          ]
        },
        {
          "endpoint": "high specific impulse",
          "status": "NASA lists 3000 s for the historical Nano gamma entry; the original vendor datasheet URL is no longer available. Current Nano-family materials cover different product variants, so they do not independently validate this historical value.",
          "sources": [
            "https://www.nasa.gov/wp-content/uploads/2026/05/4-in-space-propulsion-chapter-2026-final.pdf",
            "https://www.enpulsion.com/data-sheets/"
          ]
        }
      ],
      "unit_note": "NASA 2026 Table 4-1's 20 μN is the lowest listed nominal survey value, not the minimum operating capability. Table 4-8 PDF reads [μN], CMNT (4x heads), 4 x 20; NASA's 2017 flight paper establishes each head's 5–30 μN throttle range, supporting 20 μN per head as the nominal-row interpretation. Four heads at that nominal point sum arithmetically to 80 μN only if all operate together; the table does not claim that simultaneous flight condition. NASA's live HTML labels the same Table 4-8 column [mN], apparently a factor-1000 label/version error relative to the PDF and primary flight report."
    },
    {
      "name": "Gridded ion",
      "survey_range": {
        "thrust_mN": [
          0.1,
          20
        ],
        "specific_impulse_s": [
          500,
          3000
        ]
      },
      "findings": [
        {
          "endpoint": "low thrust / low specific impulse",
          "status": "NASA's summary Table 4-1 reports 0.1 mN and 500 s as category lower bounds, but this audit did not identify either lower bound in a named-device row of detailed Table 4-9. Keep them as summary-table ranges, not verified device capability limits or a paired operating point.",
          "sources": [
            "https://www.nasa.gov/wp-content/uploads/2026/05/4-in-space-propulsion-chapter-2026-final.pdf"
          ]
        },
        {
          "endpoint": "high thrust / high specific impulse",
          "status": "The T5 entry supports an approximately 1–20 mN throttle/capability range and Isp up to 3000 s in cited material. The upper values are reported capability bounds, not proof of a single exact measured endpoint pair.",
          "sources": [
            "https://electricrocket.org/2019/688.pdf",
            "https://www.esa.int/Applications/Observing_the_Earth/FutureEO/GOCE/GOCE_s_electric_ion_propulsion_engine_switched_on",
            "https://ukseds.org/wp-content/uploads/2017/02/GOCE_System_Critical_Design_Review.pdf"
          ]
        }
      ]
    },
    {
      "name": "Hall effect",
      "survey_range": {
        "thrust_mN": [
          0.25,
          55
        ],
        "specific_impulse_s": [
          200,
          1920
        ]
      },
      "findings": [
        {
          "endpoint": "low thrust / low specific impulse",
          "status": "NASA's listed MUSIC-SI values are <0.25 mN and <200 s. The summary table's 0.25 and 200 do not preserve those strict inequalities, so the exact lower endpoints cannot be recovered from that row.",
          "sources": [
            "https://www.nasa.gov/wp-content/uploads/2026/05/4-in-space-propulsion-chapter-2026-final.pdf"
          ],
          "source_locator": {
            "printed_page": 114,
            "pdf_page": 59,
            "table": "Table 4-10: Hall-Effect Electric Propulsion Thrusters",
            "row": "MUSIC-SI"
          },
          "source_note": "NASA lists thrust <0.25 mN and specific impulse <200 s for this entry; its summary table rounds those values to 0.25 mN and 200 s."
        },
        {
          "endpoint": "high thrust / high specific impulse",
          "status": "55 mN and 1920 s are associated with the survey's MaSMi entry. A 2019 published characterization reports peaks of 68.6 mN and 1940 s at 1 kW. Configuration differences need resolving before treating this as an inconsistency; neither survey value is a class ceiling.",
          "sources": [
            "https://www.nasa.gov/wp-content/uploads/2026/05/4-in-space-propulsion-chapter-2026-final.pdf",
            "https://doi.org/10.1088/1361-6595/ab47de"
          ]
        }
      ]
    },
    {
      "name": "Pulsed plasma / vacuum arc",
      "survey_range": {
        "thrust_mN": [
          0.004,
          0.5
        ],
        "specific_impulse_s": [
          87,
          3200
        ]
      },
      "findings": [
        {
          "endpoint": "low thrust",
          "status": "NASA lists 3.75 μN for ND-15 (rounded to 4 μN in Table 4-1). Neumann's sheet gives 45 μN·s minimum impulse bit and 83 mHz maximum frequency; multiplying yields 3.735 μN as a reconstructed mean, but their simultaneous operating point is not stated.",
          "sources": [
            "https://neumannspace.com/wp-content/uploads/2023/09/Neumann-Drive-Datasheet_Sept-2023.pdf"
          ]
        },
        {
          "endpoint": "high thrust / high specific impulse",
          "status": "CU Aerospace's FPPT-1.7 manufacturer sheet states 0.50 mN at 96 W and a maximum Isp of 3200 s. The sheet describes its values as informational rather than design data; it is system-level catalog evidence.",
          "sources": [
            "https://cuaerospace.com/Portals/0/SiteContent/assets/PDF/FPPT-Datasheet-v20.pdf"
          ]
        },
        {
          "endpoint": "low specific impulse",
          "status": "AIS lists 87 s for its VAT1-PQ product. This is manufacturer data; NASA's survey separately cautions that such claims are generally not independently verified.",
          "sources": [
            "https://appliedionsystems.com/portfolio/ais-vat1-pq-micro-vacuum-arc-thruster/"
          ]
        }
      ],
      "unit_note": "NASA's 2026 HTML Table 4-11 labels thrust in mN, but the downloadable PDF Table 4-11 uses μN for the same numeric values: ND-15 is 3.75 and FPPT-1.7 is 500 in both copies. PDF Table 4-1 summarizes these as 4–500 μN, consistent with the detailed PDF table (3.75 rounded to 4). The HTML header therefore appears wrong by a factor of 1000; this is a source-version discrepancy, not a change in the devices' performance.",
      "source_locators": {
        "device_rows_pdf": {
          "source": "NASA 2026 downloadable PDF",
          "table": "Table 4-11: Pulsed Plasma and Vacuum Arc Electric Propulsion",
          "printed_page": 116,
          "pdf_page": 61,
          "header": "Thrust [µN]",
          "comparison_rows": [
            "Neumann ND-15: 3.75",
            "CU Aerospace FPPT-1.7: 500"
          ]
        },
        "device_rows_html": {
          "source": "NASA live HTML edition, accessed 2026-10-05",
          "url": "https://www.nasa.gov/smallsat-institute/sst-soa/in-space_propulsion/",
          "table": "Table 4-11: Pulsed Plasma and Vacuum Arc Electric Propulsion",
          "header": "Thrust [mN]",
          "comparison_rows": [
            "Neumann ND-15: 3.75",
            "CU Aerospace FPPT-1.7: 500"
          ]
        },
        "category_summary_pdf": {
          "source": "NASA 2026 downloadable PDF",
          "table": "Table 4-1: Summary of Propulsion Technologies Surveyed",
          "printed_page": 66,
          "pdf_page": 11,
          "range": "Pulsed Plasma and Vacuum Arc Thrusters 4–500 µN"
        }
      }
    },
    {
      "name": "Ambipolar",
      "survey_range": {
        "thrust_mN": [
          0.5,
          17
        ],
        "specific_impulse_s": [
          400,
          1100
        ]
      },
      "findings": [
        {
          "endpoint": "low thrust",
          "status": "T4i lists 0.55 mN at 50 W for its integrated REGULUS-50 system; this is a manufacturer nominal point.",
          "sources": [
            "https://www.t4innovation.com/regulus-50-electric-propulsion-system/",
            "https://www.t4innovation.com/wp-content/uploads/2025/09/DSH_000010_05_T4i_Product_Overview.pdf"
          ]
        },
        {
          "endpoint": "high thrust",
          "status": "NASA's 2022 survey table lists the Miles M1.4 (water) at 2.8 mN, 1,340 s, 3.3 kN-s and <11.5 W. NASA's later 2024 and 2026 tables list 17.2 mN, 6 W, and no specific-impulse or total-impulse value. The rows also differ in listed mass and envelope. These are survey entries, not matched primary test records; test conditions and configuration equivalence remain unresolved, so the higher later thrust entry is not evidence of a measured 6.1-fold performance improvement. This bounded audit did not locate an independently traceable primary thrust test.",
          "sources": [
            "https://miles-space.com/thruster/",
            "https://www.nasa.gov/wp-content/uploads/2023/05/2022-soa-full.pdf",
            "https://ntrs.nasa.gov/api/citations/20250000142/downloads/SOA_2024_final.pdf",
            "https://www.nasa.gov/wp-content/uploads/2026/05/4-in-space-propulsion-chapter-2026-final.pdf"
          ]
        },
        {
          "endpoint": "specific impulse range",
          "status": "400 s and 1110 s are nominal system/catalog values for different Maxwell configurations and propellants. The exact complete-system endpoint test values were not confirmed in primary published data in this bounded audit.",
          "sources": [
            "https://www.nasa.gov/wp-content/uploads/2026/05/4-in-space-propulsion-chapter-2026-final.pdf"
          ]
        }
      ]
    }
  ],
  "nasa_2026_html_pdf_thrust_header_crosswalk": {
    "scope": "Header-unit comparison only for detailed electric-propulsion Tables 4-7 through 4-12; this is not a full cell-by-cell or claim audit of both editions.",
    "html_url": "https://www.nasa.gov/smallsat-institute/sst-soa/in-space_propulsion/",
    "pdf_url": "https://www.nasa.gov/wp-content/uploads/2026/05/4-in-space-propulsion-chapter-2026-final.pdf",
    "tables": [
      {
        "table": "4-7",
        "pdf_page": 56,
        "pdf_header": "mN",
        "html_header": "mN",
        "result": "matches"
      },
      {
        "table": "4-8",
        "pdf_page": 57,
        "pdf_header": "μN",
        "html_header": "mN",
        "result": "mismatch"
      },
      {
        "table": "4-9",
        "pdf_page": 58,
        "pdf_header": "mN",
        "html_header": "mN",
        "result": "matches"
      },
      {
        "table": "4-10",
        "pdf_page": 59,
        "pdf_header": "mN",
        "html_header": "mN",
        "result": "matches"
      },
      {
        "table": "4-11",
        "pdf_page": 61,
        "pdf_header": "μN",
        "html_header": "mN",
        "result": "mismatch"
      },
      {
        "table": "4-12",
        "pdf_page": 62,
        "pdf_header": "mN",
        "html_header": "mN",
        "result": "matches"
      }
    ]
  },
  "limitations": [
    "This is a bounded source-to-claim audit, not an exhaustive literature review or independent device test campaign.",
    "Manufacturer data are specifications or claims unless a test report is explicitly identified; flight heritage of one system does not validate all category endpoints.",
    "The survey aggregates device classes, variants, propellants, power levels, system boundaries and evidence maturity; extrema should not be joined into synthetic performance curves."
  ]
}