USA in Space collects 280 essays on the major space programs, piloted and robotic missions, satellites, space centers, space planes, and issues from the earliest missions to the present. The many changes in the space program over the past half decade made a careful reading of every page necessary to ensure the content's accuracy. ""USA in Space, Third Edition"" updates the Second Edition (3 vols., 2001) with 42 new essays plus 5 replaced essays for a total of 280 essays. The editors - longtime historian of the space program Russell R. Tobias, joined in this edition by David G. Fisher, Associate Professor of Physics and Astronomy, Lycoming College, Williamsport, Pennsylvania - carefully pored over all the old essays, revising and often adding paragraphs of material to bring the text up to date. All bibliographies have been expanded with annotated citations to the latest sources for fuller information and background. Coverage in the third edition reflects both new missions and corrections to and expansions upon previous ones. The scope of space exploration history has been extended at both ends: two essays on the history of rocket science have been added, as well as the latest missions - both piloted missions such as the International Space Station and science probe missions such as Deep Impact. The new essay on Space Shuttle Mission STS-107 (2003), in which seven astronauts tragically lost their lives aboard the orbiter Columbia upon reentry into Earth's atmosphere, is accompanied by candid discussion of the institutional conditions that may have contributed to the accident as well as consideration of the direction in which space exploration is headed. The latest essay covers the return to space, Space Shuttle Mission STS-114, in August of 2005. In addition, several essays address missions that have yet to be launched but have already undergone years of planning and development. Despite the title ""USA in Space"", the increasingly international nature of space exploration is acknowledged here as well. The International Space Station, Russia's Soyuz and Progress spacecraft, and the contributions of Canada, Japan, China, India, and many European nations in spacecraft, science experiments, equipment, and personnel are well represented among these pages. Articles are arranged in alphabetical order by key word, and by chronological order within groupings. Hence, the reader will find articles on the Apollo missions under ""A"" in volume 1; space shuttle missions are covered under ""Space Shuttle."" Within these groups the missions are ordered chronologically. Explorer satellites from mission 1 through Solar Explorers are covered under ""Explorers,"" although those Explorer missions with distinctive names.