"This dictionary was orignally published as NASA SP-7 in 1965. The editor for the first edition was William H. Allen. The introduction to the first edition describes how the original dictionary was prepared. The Web edition cannot hope to match the rigorous procedures followed by the original, but it is hoped that it will still be useful. The dictionary's accuracy will depend on the quality of feedback that we get from users. Because the original text is from 1965, many terms that are commonly used today, such as "space shuttle," are not to be found in the dictionary. We hope to add such terms along with NASA names, SI units (e.g., changing cycles per second to Hz), and other modernizations, as a matter of course. Because the original dictionary was 30 years old when we started, a few of the definitions are out of date or incomplete. Most of the definitions are quite useful, however.Constructive suggestions for additions or deletions are welcome at: dictionary@lerc.nasa.gov"