Evaluation of HZETRN on the Martian surface: Sensitivity tests and model results
Open accessAbstract
The Mars Science Laboratory Radiation Assessment Detector (MSLRAD) is providing continuous measurements of dose, dose equivalent, and particle flux on the surface of Mars. These measurements have been highly useful in validating environmental and radiation transport models that will be heavily relied upon for future deep space missions. In this work, the HZETRN code is utilized to estimate radiation quantities of interest on the Martian surface. A description of the modeling approach used with HZETRN is given along with the various input models and parameters used to define the galactic cosmic ray (GCR) environment and Martian geometry. Sensitivity tests are performed to gauge the impact of varying several input factors on quantities being compared to MSLRAD data. Results from these tests provide context for inter-code comparisons presented in a companion paper within this issue. It is found that details of the regolith and atmospheric composition have a minimal impact on surface flux, dose, and dose equivalent. Details of the density variation within the atmosphere and uncertainties associated with specifying the vertical atmospheric thickness are also found to have minimal impact. Two widely used GCR models are used as input into HZETRN and it is found that the associated surface quantities are within several percent of each other.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The cylindrical geometry used to model the Martian atmosphere and surface neglects topographical details and mass shielding that may influence measured and calculated surface dose-rates.
“The cylindrical geometry used to model the Martian atmosphere and surface is commonly used in such evaluations17–19, but nevertheless neglects topographical details (i.e. nearby boulders, hills, or valleys) and mass shielding that may influence measured and calculated surface dose-rates.”
From Validated space radiation exposure predictions from Earth to Mars during Artemis-I (2025) · cites this paper as [19]
The Geometry setup (p. 3) describes a regolith sphere surrounded by a spherical atmospheric shell, not the cylindrical geometry attributed to this paper. It also models 300 g/cm² of regolith along ray paths; the cited passages do not discuss whether nearby terrain or its shielding affects dose rates. (LLM, conf=0.86)
Checked by a reasoning model — may be wrong.
Experimental — accuracy not yet measuredBackscattered neutrons contribute little to the measured absorbed dose-rate in silicon reported by the RAD detector on the Martian surface.
“Although backscattered, or albedo, neutrons are known to be present on the Martian surface17–19 and are important for human risk estimation, they contribute little to the measured absorbed dose-rate in silicon being reported by the RAD detector.”
From Validated space radiation exposure predictions from Earth to Mars during Artemis-I (2025) · cites this paper as [19]
The Sensitivity Tests (p. 5) say that roughly half of neutrons below 100 MeV are produced in the regolith and ejected upward, and that neutrons below 1 MeV make a small contribution to total exposure. They do not establish that backscattered neutrons as a whole contribute little to the absorbed dose-rate measured in RAD’s silicon detector; the small-contribution statement concerns a narrower energy range and a different exposure measure. (LLM, conf=0.78)
Experimental — accuracy not yet measured
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Cites
Measurements of energetic particle radiation in transit to Mars on the Mars Science Laboratory
Zeitlin, C., Hassler, D. M., Cucinotta, F. A., Ehresmann, B., Wimmer-Schweingruber, R. F., Brinza, D. E., Kang, S., Weigle, G., Böttcher, S., Böhm, E., et al. (2013) · Science · doi:10.1126/science.1235989 · Cited by 641 · cited 3× · see citing works
“Several models have already been compared to measurements from the Mars Science Laboratory Radiation Assessment Detector (MSLRAD) obtained in-transit to Mars (Zeitlin et al., 2013) and on the surface (Matthia et al.”
MethodThe Radiation Assessment Detector (RAD) Investigation
Hassler, D. M., Zeitlin, C., Wimmer-Schweingruber, R. F., Böttcher, S., Martin, C., Andrews, J., Böhm, E., Brinza, D. E., Bullock, M. A., Burmeister, S., et al. (2012) · Space Science Reviews · doi:10.1007/s11214-012-9913-1 · Cited by 247 · see citing works
The Martian surface radiation environment – a comparison of models and MSL/RAD measurements
Matthiä, D., Ehresmann, B., Lohf, H., Köhler, J., Zeitlin, C., Appel, J., Sato, T., Slaba, T., Martin, C., Berger, T., et al. (2016) · Journal of Space Weather and Space Climate · doi:10.1051/swsc/2016008 · Cited by 91 · see citing works
Self-citationSlaba, T. C., Blattnig, S. R., Reddell, B., Bahadori, A., Norman, R. B., & Badavi, F. F. (2013) · Advances in Space Research · doi:10.1016/j.asr.2013.02.015 · Cited by 46 · see citing works
Self-citationMcKenna-Lawlor, S., Gonçalves, P., Keating, A., Morgado, B., Heynderickx, D., Nieminen, P., Santin, G., Truscott, P., Lei, F., Foing, B., et al. (2012) · Icarus · doi:10.1016/j.icarus.2011.04.004 · Cited by 40 · see citing works
Flagged first, then by citations
Cited by
Sorted by citations
Validated space radiation exposure predictions from Earth to Mars during Artemis-I
Slaba, T. C., Rahmanian, S., George, S., Laramore, D., Norbury, J. W., Werneth, C. M., & Zeitlin, C. (2025) · npj Microgravity · doi:10.1038/s41526-025-00459-y · Cited by 11 · see citing works
Self-citation
- Authors
- Slaba, T. C., & Stoffle, N. N.
- Affiliations
- Langley Research Center (US)
- Leidos (United States) (US)
- Corresponding author
- Slaba, Tony C.
- Venue
- Life Sciences in Space Research
- Publisher
- Elsevier BV
- Published
- 2017-08
- Volume
- 14
- Pages
- 29-35
- ISSN
- 2214-5524 (ISSN-L)
- PMC
- PMC7780709
- OpenAlex
- W2592142970
- Cited by
- 19
- References
- 5
- Citations by year
- 2026: 2 · 2025: 2 · 2024: 1 · 2023: 3 · 2022: 5 · 2021: 1 · 2020: 2 · 2019: 1 · 2017: 2
- FWCI
- 1.10
- Type
- journal article
- Language
- en
- Open access
- green
- europepmc.org
- Locations
- Life Sciences in Space Research (publishedVersion)
- PubMed (publishedVersion)
- Europe PMC (PubMed Central) (acceptedVersion)
- PubMed Central (acceptedVersion)
- Funders
- National Aeronautics and Space Administration (NNJ15HK11B)
- Topics
- Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Radiation Therapy and Dosimetry
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Planetary Science and Exploration
- Physical Sciences › Engineering › Electrical and Electronic Engineering › Radiation Effects in Electronics
- Keywords
- HZETRN, galactic cosmic rays, radiation transport modeling, dose equivalent, sensitivity analysis, Mars atmosphere, Martian regolith
- MeSH terms
- Cosmic Radiation, Environmental Exposure, Extraterrestrial Environment, Humans, Models, Theoretical, Radiation Monitoring, Radiation Protection, Mars
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
