cause confusion, as all previous Atlas rockets were designated using letters, ending with the Atlas H. However, subsequent rockets were designated using Roman numerals, starting with the Atlas II. Officially, the "I" is the Roman numeral "1".

Design

Atlas I was the last use of the classic Atlas design with three engines, a jettisonable booster section, and two vernier engines. While retaining most of those features, Atlas II replaced

1.Previous
3.Next