Between December 2020 and March 2021,SpaceX(Hawthorne,CA,USA)launched four prototypes of its Starship,a behemoth rocket intended to one day shuttle people to Mars.Yet,after reaching an altitude of several miles and executing a controlled belly flop back toward to the ground,each one exploded in spectacular fashion during or shortly after landing[1].On 5 May 2021,the company achieved success with a fifth Starship,dubbed SN15(Fig.1),which nailed the landing without blowing up[2].As SpaceX—a relative newcomer in the rocketry business—marches forward on its mission to land people on Mars with its distinctive fail-fast,fix-fast approach,government-backed space agencies foresee using half-century-old nuclear propulsion and ion drive technology to ferry astronauts to the red planet and beyond.
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