RAMSESS, a Cubesat Mission for an Isotropic and Enhanced Sensibility Detection of single Solar and Galactic Radiations

It is well known that space missions, interplanetary or even in LEO, out of the Earth magnetosphere are critical with reference to the effects of space radiations, dangerous for the electronics of the spacecraft and also for humans. Main sources of radiation are the high-energy particles of the Sun, or also interacting with the Sun, i.e. the trapped protons or electrons of the inner and outer Van Allen Belts; other causes of radiation are the Galactic and extra-Galactic cosmic rays, anomalous Cosmic rays. The present paper refers to the on-going activities that have been developing for RAMSESS (RAdiation Measurement Sensor with Enhanced Sensibility for Space exploration), project funded by ASI, the Italian Space Agency, in the frame of the national program Space 19/ALCOR and entrusted to a partnership of Universities and enterprises led by Italian Aerospace Research Centre (CIRA). The project is relevant to the LEO mission of a 6U Cubesat to be launched in Polar orbit, out of the magnetosphere, and also close to the outer Van Allen Belts, for the study of the radiative environment characteristic also for interplanetary missions. In particular, the Payload of the Cubesat encompasses an innovative radiations detector of which performs a selective dosimetry of the radiative environment. One of the main objectives, indeed, of the mission is the validation in a relevant radiative environment of an innovative dosimeter, designed by Due2Lab based on the semiconductor CdZnTe (hereinafter CZT) capable of simultaneously measuring the total absorbed dose and mostly the energy and nature of each single interaction event. An interesting features of the CZD detector is its isotropy that doesn’t require particular satellite pointing specifications, privileging other advantageous attitudes, such as sun-pointing for maximize the energy caption. The 3D CZT detector's unique position-sensitivity allows to identify and reject unwanted background events also without an anticoincidence shield. For example, its 4π Compton imaging capability rejects gamma rays scattered off spacecraft, while charged particles such as electrons, protons, and ions, are distinct and recognizable. These features make CZT detectors especially suitable for space missions, where precise radiation monitoring and particle identification are critical. They can simultaneously measure total dose, individual event energy, and particle types, providing unparalleled detail and reliability. For instance, CZT detectors can monitor radiation exposure during crewed missions, map gamma-ray sources in extraterrestrial environments, and analyze cosmic radiation composition and behavior. Definition of the RAMSESS CONOPS and mission scenario aimed at maximizing the radiative species to be detected in compliance with the new ECSS guidelines for Debris Mitigation, is performed by the Politecnico of Milan. The 6U CubeSat platform has been developing by IMT, one of the Italian leaders in the space system engineering for satellites. The design is flight proven being based on past project also developed in the ESA framework. The platform encompasses higher TRL OBDH, PDU and COMMS; the OBDH has been also qualified for withstanding with higher radiation doses, i.e. more than 20krad, and for guaranteeing mitigation to the errors due to the latch-up events (SEL/SEU). The higher performances (pointing, control) ADCS design is provided by the University of Naples, Federico II. Radiation data, divided in engineering classes, processed and raw-higher-rate data, will be processed by the on-board Data Handling System designed ad hoc for the RAMSESS mission by Kayser Italia and broadcasted through a 3Mbps data link to the Mission and Payload Control Center located in Livorno and still managed by Kayser Italia.