Why an encyclopedia on all spacecraft ever launched? Because, beyond all projects, plans, "what we will do..." and "what we could have done if...", this is what Space exploration and operations are all about. This website tries to present the most comprehensive views of all spacecraft ever launched (successfully or not) sponsored by every governments, organizations and corporations since October 1957. With more some 7,500 spacecraft, this encyclopedia represents a collossal endeavour which is only possible by starting with the works of such "giants" as Jonathan McDowell, Mark Wade, Asif Siddiqi, NASA Historians, NSSDC and many other sources. The basic data for each spacecraft are presented in an entry written in "plain english", trying to be as accurate and concise as possible. Entries are grouped by year of launch, that is: entries for all spacecraft launched in a given year are on the same web page. Additional informations are available from the web links presented at the bottom of each entry. See also: Spacecraft stats and insights, an introductory essay published in Space Review on April 5, 2010.