Why has the 'true' Speedmaster Moonwatch not been upgraded to a sapphire crystal?
Back in the 1960's, many watches used either mineral glass or acrylic (plastic) crystals. These are not difficult to scratch, but very inexpensive to replace. Now though, most all luxury watches use the highly scratch resistant synthetic sapphire crystals. Yet while OMEGA offers the sapphire crystal on all their other models, the classic Speedmaster Professional "Moonwatch" still uses the same Hesalite (a name brand of fine acrylic) crystal as is did decades ago.
The reason for this is directly related to its certification for use in space. While sapphire crystals are less prone to scratching, they can be shattered. When shattered, they break into tiny fragments that would be hazardous in a zero gravity environment.
So the Hesalite crystal is maintained on that specific model as a safety feature for its use in space flight missions.
OMEGA has since added a similar model SpeedMaster Professional that does have the sapphire crystal, but the original version with the Hesalite is stil the 'true' Moonwatch.
Many people ask about upgrading the Hesalite crystal on their Speedmaster Professional "Moonwatch" to the sapphire crystal found on the similar Speedmaster Automatic. But this is not possible. While the watches appear very similar externally, the shape and fittings of their crystals are quite different and are not interchangable.
chronocentric
