How did SpaceX catch a 23-story rocket booster from space using giant mechanical arms?

The answer

On October 13, 2024, SpaceX achieved what many considered engineering's most audacious feat: catching the Super Heavy booster - the most powerful rocket stage ever flown at 232 feet tall with 33 Raptor engines generating 7,590 tons of thrust - using giant mechanical arms nicknamed 'chopsticks' mounted on the launch tower, called Mechazilla. The 275-ton booster descended from the edge of space, reignited engines to slow its descent, and was gently grasped by the two arms just meters above the launch mount. This eliminated the need for heavy landing legs (saving mass for payload) and theoretically enables same-day reuse by placing the booster directly back on the launch mount. SpaceX repeated the feat successfully on its seventh Starship flight in January 2025. The fully reusable Starship system promises to reduce launch costs to approximately $10 per kilogram to orbit, compared to $2,700/kg on Falcon 9, potentially enabling Mars colonization and orbital manufacturing at unprecedented scale.