Space debris detection from orbit: a prototype detector study

Space debris represents a serious threat for all space activities. Several studies have been carried out to tackle the problem. Some of these involve an active management of decommissioned satellites, parking them in graveyard orbits or deorbiting them until complete disintegration, while others suggest the removal of resident debris using capture mechanisms. By contrast, another line of research accepts space junk and aims at a better understanding of them, developing detection systems useful for collision avoidance purposes. Consistently with the latter approach, this work presents a novel detector prototype for the detection of space debris on orbit. Developed within the DISCARD Project, the detector is based on technology from the Mini-EUSO telescope, which is currently operating onboard the International Space Station. The objective of the project was to validate and optimize this technology for detecting small-dimension space debris, with diameter ranging from 1 to 20 cm . These small fragments pose a significant threat to operational spacecraft, but remain largely undetectable by current surveillance systems. The proposed detector uses a real-time event recognition algorithm, the Stack-CNN method. Implemented on FPGA hardware, this online trigger system is developed and patented by the University of Turin (patent number: 102021000009845), allowing for fast and efficient optical signal processing. The assembly and integration of the prototype took place at the INFN laboratories in Turin, utilizing the instrumentation and expertise of the JEM-EUSO collaboration. Focusing on validating the detector prototype and its data acquisition processes, this work demonstrated the possibility to use this novel type of detector for in-orbit space debris detection, ensuring the proper system functionality and envisaging its use onboard a CubeSat spacecraft in low Earth orbit.