First re-flight of an orbital rocket

Landing a booster proved you could recover it. Re-flying one proved the whole point. On 30 March 2017, SpaceX launched the SES-10 communications satellite using a Falcon 9 first stage that had already flown the CRS-8 mission to the ISS in April 2016 — the first time in history an orbital-class rocket booster was reused.

The booster performed flawlessly and landed a second time on a drone ship in the Atlantic. SpaceX even recovered a payload fairing half on the same flight. SES, the customer who took the risk of flying on a "used" rocket, was rewarded with a place in spaceflight history.

This single mission converted reusability from an impressive stunt into an operational reality. Within a few years, flying refurbished boosters became routine, and individual Falcon 9 first stages would go on to fly more than 30 times each.