The launch, at 6:27 p.m., marked the first time that a rocket had flown a payload to orbit, landed vertically and then been reused. The flight signaled an important landmark, capping years of work and some fiery theatrics of boosters screaming back from space only to explode in failed attempts to land on ships at sea.

AD

AD

In December 2015, SpaceX was able to land its first rocket on a landing pad at Cape Canaveral. A few months later, the company did it again, this time at sea. Since then, it has made landing rockets as exciting — or more so — than the 3-2-1, bone-rattling liftoffs of fire and smoke that have reignited interest in space exploration.

After the successful launch, an emotional Musk called it “an incredible milestone in the history of space.”

Once aloft, the Falcon 9 boosters perform a bit of aerial acrobatics, turning around and then flying back to Earth. Guided by computer algorithms and GPS navigation, they make their way through the clouds to their target, slowing down by firing their engines again until they touch down softly, with remarkable, near bull’s-eye precision.

AD

Those feats are meant to serve a higher purpose than entertaining the company’s growing and at times rabid fan base, which treats launches like groupies do rock concerts. The real goal is to dramatically lower the cost of spaceflight, making it accessible as the company pursues its ultimate goal of reaching Mars.

AD

That has taken a lot of ingenuity — and computing power.

Up until recently, the first stages of rockets were traditionally discarded, lost in the ocean after providing the initial power to escape Earth’s gravity. But to entrepreneurs like Musk, that is an incredible waste — like throwing away an airplane after every use. The technology has also been pursued by Jeffrey P. Bezos’s Blue Origin space company, which has flown the same New Shepard booster past the edge of space five times. (Bezos owns The Washington Post.)

AD

“We’re not one-way-trip-to-Mars people. We want to make sure that whoever we take can come back. And from that perspective, you have to have a reusable system,” Gwynne Shotwell, SpaceX’s president, said during the company’s live broadcast before the launch. “We’re really looking for true operational reusability, like an aircraft.”

AD

Thursday’s flight was the first time a rocket designed to deliver a payload to orbit — a more difficult feat than Blue Origin’s suborbital flights — had been launched anew. It came during a mission to deliver a commercial satellite for SES, a Luxembourg-based satellite operations company, to what’s known as geostationary orbit, more than 22,000 miles high.

“What SpaceX did today is a historic accomplishment,” said Alan Stern, a former NASA executive and chairman of the board of the Commercial Spaceflight Federation. “They are transforming the future of space exploration.”

AD

Martin Halliwell, SES’s chief technology officer, said the company had no concerns about putting its satellite, which would help beam high-definition television to parts of Mexico and South America, on a used rocket. The company thoroughly vetted the rocket along with SpaceX, which spent months examining and testing it ahead of the launch, he said.

AD

And it looked good for a rocket that’s been flown before, Halliwell said. Any wear and tear were signs of pride.

“It hasn’t been repainted,” he said. “I believe Elon specifically didn’t want it repainted. . . . It doesn’t look all scruffy and scorched and sooty. It looks pretty good.”