On May 24th 1962, Scott Carpenter orbited the Earth three times aboard the Aurora 7 capsule. On his wrist was a Navitimer with a 24-hour graduation – a vital necessity in distinguishing day from night. It thus became the first wrist chronograph to travel in space. Having entered the Breitling collections under the name Cosmonaute
The 12023 special editions of the Cosmonaute are among the rare Breitling models to have see-through casebacks. Those were apparently produced in less than 3,000 pieces, from 1993(?) to 1997(?).
There are several known versions for this chronograph:
A12023, fully in stainless steel, with black dial or blue dial (both with silver subdials);
D12023, with a stainless steel case and yellow solid gold bezel and main hands; they came with the aforementioned black and blue dials, plus a silver dial with golden subdials.