Space radiation monitoring plays an important role in space system engineering. The radiation environment in space has a significant effect on the design considerations of spacecraft. During this thesis performed at CERN, there was research conducted on the Space RadMon-NG payload. The payload is designed as radiation monitor for CubeSats, containing mostly Commercial Off The Shelf components. The payload is able to measure Total Ionizing Dose using the Floating Gate Dosimeter and it is also able to measure the High Energy Hadron Fluence using a commercial SRAM device. The payload was system-level tested in CHARM for its operational and sensor performance. The Floating Gate Dosimeter was temperature characterized for the space environment. Payload data from a previous version of the Space RadMon payload on a mission called CELESTA, were also analyzed.