  We present the design and preliminary calibration results of a novel highly
miniaturised particle radiation monitor (HMRM) for spacecraft use. The HMRM
device comprises a telescopic configuration of active pixel sensors enclosed in
a titanium shield, with an estimated total mass of 52 g and volume of 15
cm$^3$. The monitor is intended to provide real-time dosimetry and
identification of energetic charged particles in fluxes of up to 10$^8$
cm$^{-2}$ s$^{-1}$ (omnidirectional). Achieving this capability with such a
small instrument could open new prospects for radiation detection in space.
