**Preface**

In the last 20 years, small satellites have created a paradigm shift in the world of space missions. While, at first, they were deemed suitable only for academic and amateur projects, today, they are employed in large-scale industrial projects that have previously made use of larger satellites. Smaller dimensions, lower costs, use of standards, faster and in-series production are some of the elements that have contributed to the success of these platforms. Small satellites provide a robust and agile alternative to traditional satellites, which has enabled innovative concepts of space missions. Remote sensing, telecommunications, scientific exploration, and data collection systems are some of the applications where small satellites have been massively introduced due to the short revisit times and global coverage that can be obtained if large numbers of small satellites are used.

The aim of this book is to present new insights to the reader and to bring together the state of the art in the field of small satellites. The two main topics of this book are the applications of small satellites in commercial and scientific missions, and the spacecraft subsystem technologies that are being proposed to enable the aforementioned concepts and missions. The reader will find analyses of real missions and in-orbit data in the small satellites missions section, as well as examples of the design of advanced technological solutions in the spacecraft subsystem section.

The challenges posed by modern space missions require novel solutions in space systems. The contributions of this book indicate a growing awareness of the importance of small satellites to meet these challenges, both from researchers and from engineers. We hope that this book will contribute to increase the knowledge of the scientific and industrial space communities.

> **Simone Battistini, Filippo Graziani, and Mauro Pontani** *Editors*
