Why SpaceX Built Starship Out of Stainless Steel

Business Onion · Part 1 - The Steel Decision · 2:57

Starship, the most powerful rocket ever flown, is built from stainless steel — but it was supposed to be carbon fiber. In October 2018, a month after announcing a paying passenger for a trip around the Moon on the carbon-fiber design, Elon Musk cancelled it. Part 1 of BUILDING STARSHIP: why cheap steel let SpaceX build rockets fast enough to test, learn and build the next one. Numbers & sources: the ~$200/kg (carbon fiber, $135/kg plus ~35% scrap) and ~$3/kg (stainless steel) figures are Musk's own, from his Popular Mechanics interview (published 22 Jan 2019) — material cost per kilogram, not vehicle cost. Steel is heavier than carbon fiber at room temperature; Musk's case was that it gets stronger when super-cold and handles reentry heat far better, so a steel ship needs less heat shield. The Port of Los Angeles tent scene and "What about going with stainless steel?" are from Walter Isaacson's biography, Elon Musk (2023). Raptor was the first full-flow staged-combustion engine to FLY (Starhopper, July 2019); earlier full-flow engines only reached test stands. Sources: Musk to Popular Mechanics (Jan 2019); Musk's Starship update, Boca Chica, 28 Sep 2019; Everyday Astronaut interview (Oct 2019); Musk posts on X; Isaacson, Elon Musk (2023); Ars Technica reporting by Eric Berger (2019–20). Some scenes are cinematic reconstructions of documented events. All quotes, dates, and figures are verified.