Proper assessment of any potential adverse effects is a vital part of the engineering process leading to the production of a spaceborne instrument. Besides thermal, stress and vibration tests, this also includes the evaluation of the impact of space radiation on its various components. It allows space engineers to anticipate problems that could disrupt the operation and possibly reduce the expected lifetime of the instrument.
Specify the energetic particle environment
We have used ESA’s SPENVIS system, developed at our institute, to specify the energetic particle environment that the EnVision spacecraft will encounter on its way to Venus.
After quickly leaving the Earth magnetosphere, the spacecraft will be fully exposed to a constant flux of galactic cosmic rays and sporadic bursts of solar energetic particles originating from solar eruptions like flares and coronal mass ejections. Without the shielding from Earth’s magnetosphere, these high energy particles (tens of MeV up to GeV) may easily penetrate through the skin of the spacecraft and damage the inside electronic devices if not sufficiently radiation hardened.
Study effects from those estimated particles
Subsequently, we have performed Monte Carlo simulations using the Geant4 Radiation Analysis for Space (GRAS) tool and simplified geometric models of the VenSpec-H instrument and its electronics box to study the short-term (e.g. single event effects) and long-term (total ionising and non-ionising radiation doses) effects from those estimated energetic particles.
For this preliminary analysis, we also modelled the spacecraft shielding as a hollow Aluminium sphere of 400 mm radius and 1 mm thickness that was placed around the instrument. A more detailed analysis can be performed at a later stage of the mission preparation when the design of the whole spacecraft would be completed.
Report to the engineering team
Finally, the information from our analysis was reported to the engineering team responsible for building VenSpec-H.
Having a better understanding of the potential radiation environment and expected effects, can help them in selecting the appropriate electronic parts for their instrument that can tolerate the amount and intensity of high energy particle radiation.
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