Speaker
Description
As humanity prepares for a return to the lunar surface, understanding and monitoring the lunar radiation environment is more important than ever. Despite the renewed focus on missions, the lunar radiation environment has only been measured a handful of times—mainly during flybys (Lunar reconnaissance orbiter and Chandrayaan-1) and lander missions (chang’E-4 Lander). These data are spatially limited and do not provide a full picture of radiation exposure at different lunar locations or during different periods in the solar cycle. A recent research and development effort by the TU Delft aims to address this gap through the use of the Lunar Zebro rover.
The Lunar Zebro is a compact, hexapod rover with C-shaped legs, designed for rugged mobility on the lunar surface. Its small form factor allows for distributed deployment in swarms, enabling the collection of radiation data across varied terrains and over longer durations. This mobility represents an advancement over stationary dosimeters by offering spatial granularity to radiation measurements.
A custom radiation payload has been designed for this platform, centered around the Floating Gate Dosimeter (FGDOS), a miniaturized, low-power radiation sensor suited for integration on small platforms. Simulations were performed using SPENVIS for space environment modeling and GEANT4 for interaction and shielding assessments. These efforts were followed by a robust experimental characterization campaign focusing on the dosimeter’s response to radiation, temperature, and operational conditions.
The dosimeter was tested at multiple radiation facilities in a variety of configurations:
- HollandPTC (proton beam, 70-200 MeV)
- Reactor Institute Delft (low-flux Co-60 gamma irradiation)
- CERN CHARM (mixed-field)
These campaigns validated the sensor's performance in space-relevant environments, enabled expansion of the characterisation envelope of the FGDOS and informed system-level improvements of the Radiation Payload.
Future research will focus on enhancing the sensor’s sensitivity to better detect the low dose rates expected in the lunar environment, as reported in recent literature. Moreover, efforts are being made in collaboration with CERN to improve neutron detection capability. This enhancement could allow inference of local hydrogen concentrations, providing indirect insight into subsurface water ice content (a critical resource for future lunar exploration and ISRU strategies)
