Comparison of the measured and simulated dose responses within the AstroBio CubeSat payload during its mission in the Van Allen Belt

Purpose: The Astro Bio Cube Sat (ABCS) was successfully deployed in itscircular orbit at an altitude of 5850 km in the Van Allen Belt. Besides the primarymission of validating the analytical platform hosted in the payload in such a harshradiation environment, we used the telemetry data related to the dosimetry readingstransmitted during the active mission period to back-validate the satellite’s radiationtransport model, which was already used for the payload shielding design. Methods: The radiation transport model was implemented with the high-energy MonteCarlo transport code FLUKA, and the definition of the orbital radiation sources werecalculated using the SPENVIS code. In the actual work, the orbital radiation sourceswere defined at the mission epoch using SPENVIS and IRENE codes. In the FLUKAmodel, we implemented the dosimeters and further payload components, such as abattery pack and pump, which could furnish further shielding. The simulations executedwith this upgraded model estimate the average dose rate measured during the missionperiod. To quantify the model validity, we compare the simulated dose rate with theone derived by fitting the telemetric integral dose data transmitted during the mission,finding a good agreement. An analysis of uncertainties and some consideration ofspace weather conditions are also considered to explain the agreement. Conclusion: Based on the measured dose rate, the payload shielding was satisfactory.The agreement between the calculated and measured dose rates confirms theadequateness of the Monte Carlo model. Further work will be devoted to applyingbiasing techniques to speed up the simulation time.