Is there any free program (online or downloadable) to analyze the effects of the environment (radiation, micro-meteoroids...) on the spacecraft (after having defined the orbit)?
I finally found an online program to analyze the effects of the environment.
It is "distributed" by ESA and to use it you need to register or ask for a student account.
With SPENVIS, one can generate a spacecraft trajectory or a coordinate grid and then calculate:
trapped proton and electron fluxes and solar proton fluences
radiation doses (ionising and non-ionising) for simple geometries
a sectoring analysis for dose calculations in more complex geometries
damage equivalent fluences for Si, GaAs and multi-junction solar cells
Geant4 Monte Carlo analysis for doses and pulse height rates in planar and spherical shields
ion LET and flux spectra and single event upset rates
trapped proton flux anisotropy
atmospheric and ionospheric densities and temperatures
atomic oxygen erosion depths
Magnetic field line tracing is implemented, as well as the generation of world maps and altitude dependence plots of the magnetic field and the current models of the neutral atmosphere and the ionosphere.
Models for spacecraft charging, both surface charging and internal charging, are available.
A tool to visualise satellite data produces panel plots of measured quantities in combination with geomagnetic and solar indices.
Micrometeoroid and space debris models are implemented, and an impact risk analysis module is currently under development.
Lockheed Martin has developed one internally for use in the Orion capsule design. Clearly they are NOT sharing that code. It was referenced in a Space Show episode that I cannot find right now.
Much more sophisticated than just orbit, but also vehicle orientation in that orbit. And the layout of equipment, storage, and water supplies were taken into account.