This book covers advances in analogue, mixed-signal, and custom microcircuits, with a special emphasis on those designed for harsh environments. It highlights topics such as resilience to radiation, durability against aging, and reliable performance in cryogenic conditions. It also covers needs and requirements for future missions, radiation-hardened technologies, radiation effects, radiation test results, and reusable design libraries. Chapters report on theoretical research and experimental studies concerning engineering design, simulation, and testing. Based on the 10th International Conference on Advances in Analogue and Mixed-Signal Integrated Circuits for Space Applications (AMICSA 2025), held on June 16-18, 2025, in Lisbon, Portugal, this book offers a timely reference for both academics and professionals in the broad field of integrated circuits for space applications.