Silicon Photomultipliers (SiPMs) are optical sensors widely used in space applications due to their high photon detection efficiency, low power consumption, and robustness. However, in Low Earth Orbit (LEO), their performance degrades over time due to prolonged exposure to ionizing radiation, primarily from trapped protons and electrons. The dominant radiation-induced effect in SiPMs is an increase in dark current, which can compromise detector sensitivity. This study investigates the potential of thermal annealing as a mitigation strategy for radiation damage in SiPMs. We designed and tested PCB-integrated heaters to selectively heat irradiated SiPMs and induce recovery processes. A PID-controlled system was developed to stabilize the temperature at 100 °C, and a remotely controlled experimental setup was implemented to operate under irradiation conditions. Two SiPMs were simultaneously irradiated with 9 MeV protons at the EDRA facility, reaching a 1 MeV neutron equivalent cumulative fluence of (9.5 ± 0.2) × 108 cm−2. One sensor underwent thermal annealing between irradiation cycles, while the other served as a control. Throughout the experiment, dark current was continuously monitored using a source measure unit, and I–V curves were recorded before and after irradiation. A recovery of more than 39% was achieved after only 5 min of thermal cycling at 100 °C, supporting this recovery approach as a low-complexity strategy to mitigate radiation-induced damage in space-based SiPM applications and increase device lifetime in harsh environments.
In this work, the SiPiC (SiPM Pinhole Camera) Payload is detailed. This Payload will potentially be integrated in two distinct satellite missions, which will operate in Low Earth Orbit (LEO) and in a High Altitude Orbit (HAO), respectively. The SiPiC Payload has two main objectives: to test Silicon Photomultipliers (SiPMs) as visible light sensors for stimuli originating from Earth; and to perform an in-orbit validation (IOV) of the new generation of PC104-compliant LabOSat subsystems. Preliminary measurements of the Payload's operational capabilities are performed and discussed. These include payload telemetry analysis, Field-of-View tests for the Earth imaging SiPM subsystem, and performance evaluations of the new LabOSat modules for known devices under test. The measured Angular Field of View (AFOV) for the light gathering SiPM subsystem is $(6.2 \pm 0.5)^{\mathrm{o}}$, which results in a FOV of $(4333 \pm 350)$ km on the surface of the Earth at 40000 km altitude and $(54 \pm 5)$ km at 500 km altitude.
LabOSat-01 is a payload designed to perform characterization experiments on electronic devices in hostile environments. Both Commercial-Off-The-Shelf components and custom nano and micro devices were studied in the last decade with this platform. The Total Ionizing Dose (TID) received by small satellites in Low Earth Orbit was measured with LabOSat-01 using p-MOSFET COTS and the results are presented in this work. Measurements were performed on two satellite missions, each totalling 1100 days, launched three years apart. Dosimeters were integrated in different satellite positions, with different shielding, and the measured TID after 1100 days ranged from 5 Gy to 19 Gy.