... This is the (encyclopedic) "Space Dictionary" by Mr. Konstantinos D. Mavrommatis, which follows in the footsteps of his previous "Astronomy Dictionary" (2001), which was published in a second edition in 2006. I mention the previous book of Mr. Mavrommatis because in my four decades of studying astronomy, I have not encountered anything similar in the Greek language. That "dictionary" is a work (in every sense of the word) that was written with great love for the science of the sky by a distinguished mathematician, educator, gymnasium and lyceum principal, who, for almost half a century, continues tirelessly to engage in the dissemination of science, now retired, but as the president of the Astronomy and Space Society of Volos, one of the most important in our country.

That work, and its approximately 600 pages, began to be written in 1974 and rightly the author considers it a "life's work"! And so, the given book is both complete and excellently updated with the latest word in the science of astronomy, while its content, although each lemma is brief, is nevertheless concise and presented in a vivid manner, providing even inexperienced readers with a complete and understandable description of.....

....... This is a book that is truly at the forefront internationally. In fact, over the past four decades, I have delved into this type of international bibliography with particular interest, and without any exaggeration, I have not come across any similar book in any other language, as complete and extensive as these two "dictionaries" by Mr. Mavrommatis. His new book, in fact, which is published on the 50th anniversary of the space age, is particularly welcome, as the era we live in will remain written in the history of humanity as the beginning of human colonization of Space.

(Dionysis Simopoulos, Director of the Eugenides Planetarium in Athens)