ISO 14200-2021 pdf free download – Space environment (natural and artificial) — Process-based implementation of meteoroid and debris environment models (orbital altitudes below GEO + 2 000 km).
5 Procedures for the selection and implementation of meteoroid and spacedebris environment models
5.1General
Meteoroid and space debris environment models can be used to estimate the impact fluxes ofmeteoroids and space debris on a spacecraft. This flux information can be used in
a) the selection of the spacecraft operation orbit in mission analysis,
b)the evaluation of the safety of specific orbit(s),
the prediction of the frequency of collision avoidance operations, andd) the design of suitable impact protection, especially for critical components.
There is a variety of environment models available, each with its own set of characteristics andcapabilities. 5.2 and 5.3 specify procedures that are available to guide a user in the selection andimplementation of a suitable model.
5.2Selection procedure
5.2.1The customer and the supplier of the spacecraft shall coordinate in selecting the meteoroid andspace debris environment models that are applied to their project and agree to the conclusion.
5.2.2 To select a suitable environment model, the capabilities of available candidate models should beconsidered.
NOTE Annex A describes the capabilities of some meteoroid environment models and AnnexBdescribes thecapabilities of some space debris environment models.
5.2.3 Models other than those listed in Annexes A and B may be used.
5.2.4 When selecting an environment model, the following should be considered:a) transparency of the characteristics of the model;
b) whether the model is used by a national space agency;
cwhether the model is maintained on a regular and frequent basis;
d) the format of the output flux data, including its suitability for transfer to another model, such as an impact risk analysis code;
e) the ease of use of the model.
5.2.5 When selecting an environment model, consideration should be given to the fact that there canbe significant differences in the calculated fluxes among the available candidate models. The customerand/or the supplier should compare the fluxes of several models. See A.3 and B.3.
NOTE The choice of model to be applied depends on the mission objectives and requirements of the customer(and the supplier, if necessary). For example, to achieve adequate safety margin in the design of a spacecraft orits subsystems, it is reasonable to select the model with the highest flux values when analysing the risk caused byspace debris and meteoroid impacts.This ensures that the worst-case scenario is evaluated.On the other hand,in the case of in situ debris sensor design, the worst-case scenario is achieved by using the model that generatesthe lowest impact flux values, since it results in the smallest observation opportunity.Finally, when selecting theoperational orbit of a spacecraft by comparing the impact flux for each candidate orbit, the model can be chosenaccording to criteria other than the magnitude of its flux values.This is because the analysis involves relativefluxes.
5.3 Implementation procedure
5.3.1Traceability of the implementation of the meteoroid and space debris environment models shallbe assured, including during all design and operation phases, if applied to a spacecraft.
5.3.2 When applying a model to calculate meteoroid or space debris impact fluxes, a record of thefollowing shall be kept:
a) the justification of the selected model;
b)all input and output parameters and their values for each analysis case;
any assumptions made regarding the input parameters and the technical justification for the
assumptions;
d) any corrections and/or additional assumptions made to output parameters, their technical
justification, and details of correction methods and their effects on the results.
NOTE Output parameters can be corrected by applying a safety factor, life factor or margin of safety.Such corrections can also be applied to the debris population, especially if there has been a sudden largeincrease in the population due to a debris generation event that has not yet been modelled.
e)The results of the impact flux assessment and the methodology used.
5.3.3 The records shall be evaluated and confirmed by reviewers during the appropriate review stagesof a project.ISO 14200 pdf download.