The Speedmaster Professional has since its introduction in 1957 come in a truly bewildering variety of shapes, sizes, designations and limited editions, but one of the most polarizing models, when it appeared, was the X-33. The X-33 was introduced, in the first version, in 1998; it was the result of an Omega development program designed to (finally) produce a multifunction quartz watch that would be a completely modern successor to the mechanical Speedmaster Professional, and that would meet up to date NASA and ESA requirements for a flight-qualified timepiece. It was an ambitious project, which took place over the course of five years, and prototypes were flight-tested by both American and European astronauts; the first version of the X-33 would go on to be used by U.S., European, and Soviet astronauts on the Space Shuttle, the Mir Space Station, and other missions and it was used by military flight crews as well. Version 2 of the X-33 was introduced in 2001, and for much of its life regular Joes couldn’t buy one at all –Omega decided to make them available, in 2006, only to active duty astronauts and military flight crews for a period of time, which was a big disappointment for military and aviation flight watch enthusiasts. Today, however, the X-33 is available again. (The name, by the way, was taken from that of a prototype successor to the Space Shuttle – the X-33 was a demonstrator for a “single-stage-to-orbit” vehicle but the program was eventually scrubbed.)