Finding: The Meteoroid Environment Model incorporates in its predictions the latest available data on the meteoroid environment, including the directionality and full velocity distribution of the meteoroids. It is currently the NASA model that is most consistent with the known meteoroid environment, although some major uncertainties still remain.
Recommendation: The NASA meteoroid and orbital debris programs should establish a baseline effort to evaluate major uncertainties in the Meteoroid Environment Model regarding the meteoroid environment in the following areas: (1) meteoroid velocity distributions as a function of mass; (2) flux of meteoroids of larger sizes (>100 microns); (3) effects of plasma during impacts, including impacts of very small but high-velocity particles; and (4) variations in meteoroid bulk density with impact velocity.
Finding: The earlier SSP 30425 meteoroid model does not reproduce existing observational meteoroid data with a fidelity equal to that of the Meteoroid Environment Model. Numerous disparate sources of data have been fused to produce the current meteoroid flux model used by NASA, sometimes incorporating differing underlying assumptions.
Finding: The Meteoroid Environment Model currently does not extend to prediction of the meteoroid environment in the outer solar system, and the measurements it incorporates are poorly constrained in the cis-martian region.
Recommendation: An effort should be made to re-examine earlier data used in the Grün Interplanetary Flux Model and to reconcile the data with more recent measurements in the literature on meteoroid flux, and a technical evaluation should be undertaken to synthesize and document such data as it is incorporated into the Meteoroid Environment Model (MEM). Updates of the MEM and technical development should follow a technical pathway as rigorous as that being taken for updates of the Orbital Debris Environment Model.
Recommendation: NASA should adopt the Meteoroid Environment Model for agency-wide official use and extend its capabilities to the outer solar system.