On Monday night, Elon Musk jumped out of his space company's launch control centre to watch this one live.
The last time SpaceX launched a rocket, it blew up in a fireball. This one had to go right. But he always wanted to see if the company would be able to land the first stage of the rocket, a momentous first.
He was relieved that the launch went off flawlessly; that was the main goal. Then he saw the rocket reappear in the darkness over the Florida Space Coast, tilting toward a landing pad at Cape Canaveral. It seemed to be right on the mark, but then there was a massive boom, and he thought the worst: "It had exploded."
"Well, at least we got close," he said to himself.
But then he went back inside, and people were agog. The sound was a sonic boom-- the shock wave of a rocket traveling through the air faster than the speed sound.
"There was this amazing video of the rocket standing there," he recounted in a call with reporters Monday evening.
It was still standing there Tuesday morning. Viewed from this fishing vessel chartered by SpaceX, it towered some 15-stories tall, right next to the launch pad that shot John Glenn into orbit.
Many in the space community heralded SpaceX's achievement of shooting a rocket into space and then recovering the first stage as another momentous step in the history of space flight, one they hope will touch off a boom in commercial space.
Being able to recover and reuse the first stage of rockets - the most expensive part because they house the engines - would dramatically lower the cost of space travel, a key step in making space more accessible.
"It would be like having an aircraft used many times when all the other aircraft could only be used once," he said.
Watch the previous landing attempt fail.
The savings with reusing a rocket would be substantial. The Falcon 9 costs about $60 million to build, and that's on the low end, Musk said, and the fuel costs an additional $200,000.
"This may one day be looked back upon as the day that the Space Age really began, because it showed that you can return a stage for reuse without a huge standing army of technicians to do it - unlike the shuttle," Charles Lurio, who writes a space newsletter wrote Monday evening after the launch and landing.
For Musk, whose main goal is the colonization of Mars, the landing shows that the technology to reuse powerful rockets is real.
"I think it really quite dramatically improves my confidence that a city on Mars is possible," he said on a call with reporters Monday evening. "That's what all this is about."
Last month, Jeff Bezos' space company also landed a first stage on land. And on Twitter he congratulated SpaceX, and said: "Welcome to the club!"
But the landing SpaceX pulled off was far more difficult. Bezos' New Shepard vehicle made it just past the boundary of space, or about 60 miles, during a test flight. Musk's Falcon 9 is a much bigger, more powerful rocket designed to launch payloads into orbit, which makes the landing feat all the more complex.
The landing also came as part of a mission - to launch the satellites into space - and not just a test flight. And SpaceX pulled off its feat in front of the world, broadcasting the launch and landing on its website so that everyone could see the triumph - or what could have been another spectacular failure.
Musk said the company would soon move the booster stage to a nearby landing pad to test fire it. But while the goal is ultimately to launch rockets and reuse them, he said this one would probably be preserved as a historical artifact.
Now, the company will focus on perfecting landings, Musk said. And it is working on several other fronts as well. Along with Boeing, SpaceX currently is under contract by NASA to launch astronauts to the International Space Station.
The first flight is expected in late 2017, which would mark the first time the US has launched astronauts to space from US soil.