Death Star — The Original Flaw

One of the most famous accidents in design history: when Colin Cantwell was constructing his foam model of the Death Star, the two hemispheres didn’t fit together cleanly, leaving a visible equatorial trench. Rather than rebuild, Cantwell showed it to Lucas, who loved the imperfection — it gave the otherwise featureless sphere visual interest and, crucially, a surface detail that would become the setting for the film’s climactic trench run. A manufacturing flaw became a plot point that defined the entire franchise.