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Erklärung der SpaceX Landung von Raketen und die Technik warum die Falcon 9 nicht schweben kann

SENKRECHTSTARTER · August 3, 2022 · 13:08 · German · Documentary

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Video from the channel SENKRECHTSTARTER about Falcon 9, linked on its Above Ten Thousand entry. Duration: 13:08. Language: German. Video type: Documentary.

What it's about

German-language explainer video on how the Falcon 9's first stages and the Falcon Heavy's boosters land, and why the Falcon 9 can't hover in the air when landing. It uses Blue Origin's New Shepard as a contrast, which does slow down and hover before touching down. It ends with Starship and its belly-flop maneuver.

Historical context

The author notes that SpaceX didn't invent vertical landing: the DC-X prototype already demonstrated it in the 1990s. Before that, the Space Shuttle had tried reusability without meeting its safety, speed, and cost goals. The Dragon capsule was meant to land using its own engines, but NASA rejected that option for safety reasons.

Key figures

Even throttled to the minimum, a Merlin produces about 50 tonnes of thrust, almost double the stage's dry mass. That's why the final burn has to end right as it touches the ground: the so-called "suicide burn," now called "hoverslam." The atmosphere slows the stage from over 6,000 to under 1,000 km/h without using any fuel. The legs deploy by inertia and absorb the impact with aluminum honeycomb cores that are single-use only. The author estimates that recovery accounts for between 20 and 30 of the 550 tonnes at liftoff. He cites 22.8 tonnes to low Earth orbit in expendable mode versus 16.4 when the stage is recovered.

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