Technology20th century (1960s)United Stateslow confidence

Engineers used hundreds of cameras inside the F-1 engine's thrust chamber and detonated pyrotechnic 'bombs' outside it to study combustion instability in its oxygen-rich combustion zone.

Notes on verification

Confirmed by Smithsonian oral history and independent aerospace history source (enginehistory.org) describing the same bomb-testing and camera methodology used by Rocketdyne engineers on the F-1 engine.

Sources