This book introduces an important and interesting aspect of space exploration technology: 3D printing in space. It explores the key techniques and application scenarios of this innovative technology. With several countries announcing moon missions, the dream of venturing into the vast universe is becoming a reality. 3D printing offers immense potential for space exploration efforts. Featuring over 100 color graphics, this book not only explains fundamental theories and research advances in an easily understandable way but also addresses practical questions like achieving "waste recycling" in spacecraft and printing "houses" on the moon's surface. Additionally, it provides insights on dealing with component failures during deep space missions. Drawing from the authors' extensive research and development work in satellite payload technology, this book combines solid theoretical knowledge with practical engineering experience. It is a valuable resource for students, researchers, and engineers interested in space exploration and astronautics. Let this book serve as a vessel for readers to embark on their journey through the sea of stars. The English translation of this book, originally in Chinese, was facilitated by artificial intelligence. The content was later revised by the author for accuracy.