Space Sciences, 2nd Edition is part of the Macmillan Science Library series. Its 345 entries range from roughly 400 to 5, 000 words. They are grouped into 4 subject-based volumes. It provides the latest information on all aspects of space exploration, astronomy, and their impact on daily life on Earth. All entries from the previous edition have been updated, and six new entries added. The past, present, and future of such diverse topics as Mars missions, radio astronomy, the satellite industry, and space tourism are discussed, just to name a few topics. Fifty-seven biographies of astronauts, scientists, and entrepreneurs are included in the series. Entries are written for a general audience without a science background, with technical terms defined as needed.