Captain Scarlet and the Mysterons

September 29, 1967 –

Gerry Anderson’s supermarionation take on superheroes, Captain Scarlet and the Mysterons premiered on this date in the UK.

The Spectrum organizations’ radio code SIG stood for Spectrum Is Green (essentially an OK), whilst the less used SIR stood for Spectrum Is Red (indicating a dangerous situation). Both radio codes have been borrowed by American private spaceflight firm SpaceX to describe its readiness for rocket launches, modified to “SpaceX Is Green” or “SpaceX Is Red.”