spore: profile
id: nickel-zinc-ferrite
spore_version: 0.2
family: ferrite
name: Nickel-zinc ferrite (Fair-Rite 43 Material, EMI suppression)
abbreviation: NiZn
role: EMI suppressor
category: shielding
type: spot-shields
summary: |
  Fair-Rite 43 Material is a nickel-zinc spinel ferrite, a sintered ceramic, used to suppress conducted electromagnetic interference on cables and in high-frequency common-mode chokes. Fair-Rite gives an initial permeability of 800 and a Curie temperature above 130 °C for this grade, and its supplier safety data sheet gives a specific gravity of 4.8 g/cm3. No space-flight, radiation or vacuum data for this grade were found in the sources read for this profile.
best_for: Suppressing conducted EMI on cables and wiring from 20 MHz to 250 MHz
weakest_at: Permeability changes by 1.25 %/°C over 20 to 70 °C (datasheet), and no space test data were found
identity:
  formula: Nickel-zinc spinel ferrite; nominal oxide composition 65 wt% Fe2O3, 21 wt% ZnO, 10 wt% NiO and 4 wt% CuO (Fair-Rite 43 Material Grade, RoHS composition sheet)
  cas: 12645-50-0
  source: fair-rite-43-sds
  where: CAS Number printed in SDS section 1 (product code); material named as Nickel Zinc Spinel Ferrite in section 3
  designations:
    - system: Trade name
      code: 43 Material
      source: fair-rite-43-datasheet
      where: 'Page title and heading: 43 Material Data Sheet'
tags:
  environments: []
  stresses: []
  applications:
    - electronics-and-chips
properties:
  - benchmark: initial_permeability
    label: Initial permeability (magnetic, dimensionless as printed)
    value: 800
    unit: '-'
    scope: material
    conditions:
      field: B below 10 gauss
      test: standard toroids 18/10/6 mm at 25 degC and 10 kHz unless otherwise indicated (data sheet footnote)
    method: Value in the 43 Material characteristics table, measured by the manufacturer
    status: ground
    source: fair-rite-43-datasheet
    where: 43 Material Characteristics table, row 'Initial Permeability @ B < 10 gauss'
  - benchmark: flux_density_at_field
    label: Flux density B at field strength H
    value: 3500
    unit: gauss
    scope: material
    conditions:
      field_strength: 10 oersted
      test: standard toroids 18/10/6 mm at 25 degC and 10 kHz unless otherwise indicated (data sheet footnote)
    method: Value in the 43 Material characteristics table
    status: ground
    source: fair-rite-43-datasheet
    where: 43 Material Characteristics table, row 'Flux Density @ Field Strength' (B 3500 gauss at H 10 oersted)
  - benchmark: residual_flux_density
    label: Residual flux density Br
    value: 2200
    unit: gauss
    scope: material
    conditions:
      basis: value as printed; the table row gives no temperature or field beyond the table footnote (25 degC, standard toroid)
    method: Value in the 43 Material characteristics table
    status: ground
    source: fair-rite-43-datasheet
    where: 43 Material Characteristics table, row 'Residual Flux Density' (Br)
  - benchmark: coercive_force
    label: Coercive force Hc
    value: 0.36
    unit: oersted
    scope: material
    conditions:
      basis: value as printed; the table row gives no temperature or field beyond the table footnote (25 degC, standard toroid)
    method: Value in the 43 Material characteristics table
    status: ground
    source: fair-rite-43-datasheet
    where: 43 Material Characteristics table, row 'Coercive Force' (Hc)
  - benchmark: magnetic_loss_factor
    label: Magnetic loss factor (tan delta / initial permeability)
    value: 100
    unit: 10^-6
    scope: material
    conditions:
      frequency: 1.0 MHz
    method: Value in the 43 Material characteristics table; printed as 100 at 1.0 MHz with the unit 10^-6 and MHz in the table
    status: ground
    note: The table prints the loss factor as tan delta over mu-i in units of 10^-6 at the frequency MHz. It is a magnetic loss factor, not the dielectric dissipation factor in the canonical list.
    source: fair-rite-43-datasheet
    where: 43 Material Characteristics table, row 'Loss Factor @ Frequency'
  - benchmark: temperature_coefficient_permeability
    label: Temperature coefficient of initial permeability
    value: 1.25
    unit: '%/°C'
    scope: material
    conditions:
      temperature_range: 20 to 70 °C
    method: Value in the 43 Material characteristics table
    status: ground
    source: fair-rite-43-datasheet
    where: 43 Material Characteristics table, row 'Temperature Coefficient of Initial Permeability (20 -70°C)'
  - benchmark: curie_temperature
    label: Curie temperature
    value: 130
    bound: lower
    unit: °C
    scope: material
    conditions:
      basis: printed as '>130' in the table; the value is a lower bound, not a measured Curie point
    method: Value in the 43 Material characteristics table
    status: ground
    source: fair-rite-43-datasheet
    where: 43 Material Characteristics table, row 'Curie Temperature' (Tc)
  - benchmark: conducted_emi_frequency_range
    label: Frequency range for conducted EMI suppression
    value: 20
    value_high: 250
    unit: MHz
    scope: material
    conditions:
      application: suppression of conducted EMI on cables and wiring
    method: Range stated in the 43 Material data sheet introduction
    status: ground
    source: fair-rite-43-datasheet
    where: 43 Material Data Sheet, introduction paragraph ('suppression of conducted EMI from 20 MHz to 250 MHz')
  - benchmark: boiling_point
    label: Boiling point (upper bound, as printed in the SDS)
    value: 2500
    bound: upper
    unit: °F
    scope: material
    conditions:
      basis: printed as '< 2500 °F' in the SDS; an upper bound, not a measured boiling point
      form: sintered component, 43 Material Grade
    method: Value printed in the supplier SDS, section 9
    status: ground
    note: The SDS gives the boiling point only as an upper bound. No measured boiling point for this grade was found.
    source: fair-rite-43-sds
    where: Section 9, Physical and Chemical Properties, row 'Boiling Point'
  - benchmark: complex_permeability_real_part
    label: Real part of complex permeability at 1 MHz (CSV column headed µs', the leading Greek letter is garbled in the download)
    value: 851.3550816
    unit: '-'
    scope: material
    conditions:
      frequency: 1000000 Hz (1 MHz)
      equipment: named in the CSV header (HP4284A with 16047E fixture, and E4991A with 16454A fixture)
    method: Value in the 43 Material complex permeability CSV, row Frequency(Hz) 1000000
    status: ground
    source: fair-rite-43-csv
    where: 43-Material-publish.csv, row '1000000' (first data column after frequency)
  - benchmark: complex_permeability_imaginary_part
    label: Imaginary part of complex permeability at 1 MHz (CSV column headed µs'', the leading Greek letter is garbled in the download)
    value: 48
    unit: '-'
    scope: material
    conditions:
      frequency: 1000000 Hz (1 MHz)
      equipment: named in the CSV header (HP4284A with 16047E fixture, and E4991A with 16454A fixture)
    method: Value in the 43 Material complex permeability CSV, row Frequency(Hz) 1000000
    status: ground
    source: fair-rite-43-csv
    where: 43-Material-publish.csv, row '1000000' (second data column after frequency)
  - benchmark: density
    label: Specific gravity of the 43 Material Grade component (printed as specific gravity)
    value: 4.8
    unit: g/cm3
    scope: material
    conditions:
      form: sintered component, 43 Material Grade
    method: Value printed in the supplier SDS, section 9
    status: ground
    note: Fair-Rite's generic Ferrite Material Constants block on its toroid product page prints about 4.7 g/cm3 (specific gravity, approximately) and states those constants are typical for Fair-Rite MnZn and NiZn ferrites. That figure is not specific to the 43 grade, so it is not used here. The two figures are recorded side by side for the reader.
    source: fair-rite-43-sds
    where: Section 9, Physical and Chemical Properties, row 'Specific Gravity'
corrosion:
  - environment: Water
    headline: The supplier safety data sheet describes the sintered ferrite as insoluble in water and not reactive with water.
    effect: The SDS lists solubility as insoluble and reactivity in water as none, and gives stability as stable and the material as inert. It gives no test data on humidity, ageing or chemical exposure.
    rating: low
    conditions:
      material: 43 Material Grade sintered component
      test: no test; supplier SDS statements only
    source: fair-rite-43-sds
    where: Section 9 (Solubility in Water; Reactivity in Water) and section 10 (Stability; Conditions to Avoid)
risks:
  hazards:
    - text: The supplier SDS lists no OSHA Hazard Communication classification and no physical or health hazards, marking each as N/A in section 2.
      ghs: []
      source: fair-rite-43-sds
      where: Section 2, Hazard Identification
    - text: The SDS lists the composition as nickel compounds below 23 wt%, copper compounds below 8 wt% and zinc compounds below 23 wt%, and lists these as EPCRA Section 313 chemicals.
      ghs: []
      source: fair-rite-43-sds
      where: Section 3, Composition, and the Section 313 supplier notification
  failure_risks:
    - mode: Permeability drifts with temperature
      trigger: Operation across 20 to 70 °C
      consequence: Initial permeability changes by 1.25 %/°C over that range, so the initial permeability shifts with temperature.
      severity: low
      source: fair-rite-43-datasheet
      where: 43 Material Characteristics table, temperature coefficient row
  side_effects: []
  handling:
    - text: Wear safety glasses for eye protection (SDS section 8).
      source: fair-rite-43-sds
      where: Section 8, Eye Protection
    - text: No respiratory protection or ventilation is required unless airborne dust is generated (SDS section 8).
      source: fair-rite-43-sds
      where: Section 8, Respiratory Protection and Ventilation
    - text: Clean up spills by wiping off with a brush and cloth (SDS section 6).
      source: fair-rite-43-sds
      where: Section 6, Method for Cleaning up
    - text: The SDS lists no precautions for handling and storage (SDS section 7).
      source: fair-rite-43-sds
      where: Section 7, Handling and Storage
  mitigations: []
uses:
  - application: electronics-and-chips
    device: Cable EMI suppression cores and beads
    example: Fair-Rite lists EMI suppression beads, beads on leads, round and flat cable EMI suppression cores and snap-on cores as products offered in 43 Material, for suppression of conducted EMI from 20 MHz to 250 MHz.
    source: fair-rite-43-datasheet
    where: 43 Material Data Sheet page, opening paragraph and the product list
  - application: electronics-and-chips
    device: High-frequency common-mode choke
    example: The data sheet says 43 Material is also used for inductive applications such as high frequency common-mode chokes.
    source: fair-rite-43-datasheet
    where: 43 Material Data Sheet page, opening paragraph
supply:
  - subject: Nickel
    producers:
      - country: Indonesia
        share_percent: 66.7
        year: 2025
      - country: Philippines
        share_percent: 6.9
        year: 2025
      - country: Russia
        share_percent: 5.1
        year: 2025
      - country: Canada
        share_percent: 3.6
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (Nickel, used to make high-strength steel, and rechargeable batteries)
        listed: true
    recycling: 'USGS: nickel recovered from scrap accounted for approximately 60% of apparent consumption in 2025.'
    substitutes: []
    source: usgs-mcs2026-nickel
    where: World Mine Production and Reserves table, 2025e (world total 3,900,000 t; shares calculated by Space Mushroom against that world total); Recycling paragraph
  - subject: Zinc
    producers:
      - country: China
        share_percent: 31.5
        year: 2025
      - country: Peru
        share_percent: 11.5
        year: 2025
      - country: Australia
        share_percent: 8.5
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (Zinc, used as a coating to protect iron and steel from rust and corrosion)
        listed: true
    recycling: 'USGS: refined zinc produced in the United States was recovered from secondary materials at both primary and secondary smelters (no percentage given).'
    substitutes: []
    source: usgs-mcs2026-zinc
    where: World Mine Production and Reserves table, 2025e (world total 13,000 thousand t; shares calculated by Space Mushroom against that world total); Recycling paragraph
  - subject: Iron
    producers:
      - country: Australia
        share_percent: 37.7
        year: 2025
      - country: Brazil
        share_percent: 16.2
        year: 2025
      - country: India
        share_percent: 11.9
        year: 2025
      - country: China
        share_percent: 11.2
        year: 2025
    critical_lists:
      - list: USGS 2025 List of Critical Minerals (iron is not a separate entry)
        listed: false
    recycling: 'USGS iron ore chapter: ''Recycling: None.'' It refers readers to the Iron and Steel Scrap chapter.'
    substitutes: []
    source: usgs-mcs2026-iron
    where: World Mine Production table, usable ore, 2025e (world total 2,600,000 thousand t; shares calculated by Space Mushroom against that world total); Recycling line
media: []
documents:
  - title: 'Safety Data Sheet: Soft Ferrite component, 43 Material Grade (Fair-Rite Products Corp.)'
    type: sds
    url: https://fair-rite.com/wp-content/uploads/2016/03/SDS-43-Component.pdf
    year: 2015
  - title: 43 Material Data Sheet (Fair-Rite)
    type: datasheet
    url: https://fair-rite.com/43-material-data-sheet/
    year: 2026
  - title: 43 Material Grade Nominal Chemical Composition, Fair-Rite P/N 5943000301 (RoHS sheet)
    type: datasheet
    url: https://www.fair-rite.com/wp-content/ebiz/newfair/rohs/5943000301%20ROHS.pdf
    year: 2005
  - title: 'USGS Mineral Commodity Summaries 2026: Nickel'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Zinc'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zinc.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Iron Ore'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-ore.pdf
    year: 2026
  - title: About the 2025 List of Critical Minerals (USGS)
    type: report
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
  - title: 43 Material Complex Permeability vs. Frequency (CSV, Fair-Rite)
    type: datasheet
    url: https://fair-rite.com/wp-content/uploads/2020/11/43-Material-publish.csv
    year: 2020
gaps:
  - 'Saturation flux density (Bs) for the 43 grade: not printed on the 43 data sheet; only B at 10 oersted and residual flux density are given.'
  - 'Permeability versus frequency: only the 1 MHz row of the CSV (real and imaginary parts) is used as a property; the other rows are not profiled. Permeability versus temperature: no table or CSV for it was read.'
  - Benchmark names conducted_emi_frequency_range, complex_permeability_real_part and complex_permeability_imaginary_part are not in spores/property-canon.yaml, and initial_permeability is not there either. Use the canonical names once they are added.
  - 'Specific heat (0.25 cal/g/°C), thermal conductivity (3.5 to 4.5 mW/cm-°C), linear expansion (8 to 10 x 10^-6 /°C), tensile and compressive strength, Young''s modulus and Knoop hardness: printed only in Fair-Rite''s generic Ferrite Material Constants block, which says it is typical for MnZn and NiZn ferrites, so none is listed as a 43 property.'
  - 'Operating and storage temperature for the 43 grade: Fair-Rite''s Storage and Operating Conditions page gives limits by component category, not by grade (for example -55 to +125 °C for inductive/power parts with no coatings or conductors), and does not name the 43 grade.'
  - 'Behaviour above the Curie temperature (above 130 °C): no permeability-versus-temperature result in any source read for this profile, and the failure mode above Curie is not stated.'
  - 'Electrical resistivity of the 43 grade: the data sheet prints 1×10^5 ohm-cm, but in superscript form that the automated value check could not match in the source text, so the value is not kept as a property here. Re-enter it once the printed form is confirmed.'
  - 'Space environment: no vacuum, radiation, thermal-vacuum or flight result for NiZn ferrite cores found.'
  - 'Humidity and ageing: no humidity, heat-ageing or long-term test found; corrosion entry rests only on the supplier SDS statements.'
  - 'Crystal structure: the SDS names the material as a spinel ferrite, but no crystal-structure source was read, so no crystal system or space group is given.'
  - Copper supply (CuO, 4 wt%) is not profiled in this file.
  - 'Failure modes (cracking, mechanical breakage) and mitigations: no sourced statement found.'
  - 'Comparison with MnZn ferrites: no MnZn grade was read in this run, so this profile does not compare the 43 grade with other ferrites in numbers.'
sources:
  fair-rite-43-datasheet:
    title: 43 Material Data Sheet (Fair-Rite Products Corp.)
    id: Fair-Rite 43 Material characteristics table
    url: https://fair-rite.com/43-material-data-sheet/
    year: 2026
    kind: datasheet
    license: Manufacturer web page, cited not reproduced
  fair-rite-43-sds:
    title: 'Safety Data Sheet: Soft Ferrite component, 43 Material Grade (Fair-Rite Products Corp.)'
    id: CAS 12645-50-0; prepared 05/20/2015 (SDS section 16)
    url: https://fair-rite.com/wp-content/uploads/2016/03/SDS-43-Component.pdf
    year: 2015
    kind: datasheet
    license: Supplier document, linked not reproduced
  fair-rite-43-rohs:
    title: 43 Material Grade Nominal Chemical Composition, Fair-Rite P/N 5943000301 (RoHS sheet)
    id: Fair-Rite P/N 5943000301; RoHS conversion date 1/1/2005 printed on sheet
    url: https://www.fair-rite.com/wp-content/ebiz/newfair/rohs/5943000301%20ROHS.pdf
    year: 2005
    kind: datasheet
    license: Manufacturer document, linked not reproduced
  fair-rite-43-csv:
    title: 43 Material Complex Permeability vs. Frequency (CSV, Fair-Rite Products Corp.)
    id: 43-Material-publish.csv; file header dated Feb-20
    url: https://fair-rite.com/wp-content/uploads/2020/11/43-Material-publish.csv
    year: 2020
    kind: datasheet
    license: Manufacturer data file, linked not reproduced
  usgs-mcs2026-nickel:
    title: 'Mineral Commodity Summaries 2026: Nickel'
    id: USGS Mineral Commodity Summaries 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-zinc:
    title: 'Mineral Commodity Summaries 2026: Zinc'
    id: USGS Mineral Commodity Summaries 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zinc.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-mcs2026-iron:
    title: 'Mineral Commodity Summaries 2026: Iron Ore'
    id: USGS Mineral Commodity Summaries 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-ore.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-crit-2025:
    title: About the 2025 List of Critical Minerals (USGS)
    id: Final 2025 List of Critical Minerals
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
    kind: web
    license: public domain (USGS)
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 12
  unreachable: 0
  caveats: 2
  note: Written by an AI assistant on 2026-11-01 from pages read in this run. 12 grade-specific values, 8 from the 43 data sheet and supplier SDS, plus the SDS boiling point (upper bound), the 20 to 250 MHz range from the data sheet, and the 1 MHz real and imaginary permeability from the 43 permeability CSV. The resistivity row stays out because its printed form (1×105) carries a lost superscript. Generic constants were left out. Density 4.8 g/cm3 (SDS) and about 4.7 g/cm3 (generic constants block) are recorded side by side.
story:
  recipe:
    line: Fair-Rite 43 Material is a nickel-zinc spinel ferrite. Its nominal composition is 65 wt% Fe2O3, 21 wt% ZnO, 10 wt% NiO and 4 wt% CuO, per Fair-Rite's RoHS composition sheet. The supplier SDS calls the part a sintered ceramic component.
    parts:
      - name: Iron oxide
        symbol: Fe2O3
        share_percent: 65
        role: Main component by weight in the nominal composition.
      - name: Zinc oxide
        symbol: ZnO
        share_percent: 21
        role: Zinc component of the nominal composition.
      - name: Nickel oxide
        symbol: NiO
        share_percent: 10
        role: Nickel component of the nominal composition. The SDS names the material as nickel zinc spinel ferrite.
      - name: Copper oxide
        symbol: CuO
        share_percent: 4
        role: Minor component of the nominal composition.
  risk_groups:
    - title: For people
      level: 0
      verdict: Not classified hazardous by the supplier
      lead: The supplier SDS lists no OSHA Hazard Communication classification and no physical or health hazard for the sintered component. Its toxicology and ecology entries are marked N/A.
      points:
        - label: The component
          line: The SDS says the material is inert and insoluble in water, and lists no hazardous decomposition. It is a sintered ceramic part, not a powder.
        - label: Composition
          line: The SDS lists nickel compounds below 23 wt%, copper compounds below 8 wt% and zinc compounds below 23 wt%, and notes them as EPCRA Section 313 chemicals.
        - label: Dust
          line: Eye protection is safety glasses. Respiratory protection and ventilation are needed only where airborne dust is generated, per SDS section 8.
    - title: In service
      lead: The datasheet names cable EMI suppression and high-frequency common-mode chokes as uses of this grade.
      points:
        - label: Temperature
          line: Initial permeability changes by 1.25 %/°C over 20 to 70 °C, per the 43 data sheet. The Curie temperature is printed as above 130 °C, and the sources read give no behaviour above that point.
        - label: Storage
          line: The SDS lists no precautions for handling and storage.
  why: Fair-Rite 43 Material is a nickel-zinc spinel ferrite, a sintered ceramic core used to suppress conducted electromagnetic interference (EMI) on cables and in common-mode chokes. Fair-Rite describes it as its most popular ferrite for suppressing conducted EMI from 20 MHz to 250 MHz. The supplier data give it an initial permeability of 800 and a Curie temperature above 130 °C.
  uses:
    - where: Cable EMI suppression
      line: Fair-Rite lists EMI suppression beads, beads on leads, round and flat cable EMI suppression cores and snap-on cores as products made in 43 Material, for suppression of conducted EMI from 20 MHz to 250 MHz.
    - where: High-frequency common-mode chokes
      line: The 43 data sheet says the grade is also used for inductive applications such as high frequency common-mode chokes.
    - where: Electronics industry
      line: The supplier SDS gives the product use as the electronics industry.
  can_do:
    - label: Initial permeability
      benchmark: initial_permeability
      value: '800'
      line: Initial permeability is 800 for the 43 grade, measured on standard toroids at 25 degC and 10 kHz, per the Fair-Rite data sheet.
    - label: Curie temperature
      benchmark: curie_temperature
      value: above 130 °C
      line: The Curie temperature is printed as above 130 °C. The data sheet gives only the lower bound.
    - label: Flux density
      benchmark: flux_density_at_field
      value: 3500 gauss
      line: The data sheet prints a flux density of 3500 gauss at a field strength of 10 oersted for the 43 grade.
  compare: The 43 grade is a nickel-zinc ferrite for EMI suppression from 20 MHz to 250 MHz, with initial permeability 800 and Curie temperature above 130 °C. No MnZn grade was read in this run, so this profile does not compare the 43 grade with other ferrites in numbers. The compare table lists the 43 grade's own values for the three main magnetic and physical figures.
  compare_rows:
    - label: Initial permeability
      benchmark: initial_permeability
    - label: Curie temperature
      benchmark: curie_temperature
    - label: Specific gravity
      benchmark: density
  handling:
    - The sintered component is not classified as hazardous by the supplier SDS. Wear safety glasses.
    - Respiratory protection is needed only where airborne dust is generated.
    - Clean spills by wiping off with a brush and cloth.
    - Allow for the stated temperature coefficient of permeability (1.25 %/°C over 20 to 70 °C) when designing for temperature change.
  good_for:
    - Suppressing conducted EMI on cables from 20 MHz to 250 MHz. The data sheet names this as its main use.
    - High-frequency common-mode chokes, per the data sheet.
  watch_out:
    - Permeability changes by 1.25 %/°C over 20 to 70 °C.
    - No flux density at saturation is printed for the 43 grade, and the magnetization curves were not read in this run.
    - No space, vacuum or radiation test data were found for this grade.
  verdict: The 43 grade has manufacturer data for its main magnetic figures and a supplier safety data sheet. Space-environment data are missing from every source read here.