SpaceX has sent its Starship rocket into Earth's orbit for the first time, on a flight intended to pave the way for future missions to the moon and Mars.
The rocket, the largest and most powerful ever built, blasted off from the company's Starbase launch facility in Texas at 7.48am local time, marking its 14th test flight and the first attempt to circle the planet before falling back to Earth.
An engine failure on ascent threatened to prevent Starship from reaching orbit at all. Mission controllers decided it was safe to press ahead with a burn that pushed the ship onto the planned trajectory around the planet.
Cheers broke out at SpaceX after initial suggestions that the orbit attempt might be abandoned were quashed. Moments after the orbit burn, Daniel Hewitt, an engineer narrating the live stream, declared: "Starship is in orbit."
Starship has flown in its full form since 2023, but previous test flights sought only suborbital trajectories, which are simpler and carry fewer risks for the public. On a suborbital path, a rocket that malfunctions mid-flight comes down in the Indian Ocean far from populated areas. The risks are harder to control on a full orbital path.
The vehicle soared to an altitude of about 275km. On the launchpad it stands more than 120 metres tall, with the Starship upper stage sitting on the Super Heavy booster. To remain in orbit it must travel at about 28,000km/h.
"This is an important milestone for SpaceX, with Starship successfully reaching orbit, and at the first attempt," said Martin Barstow, a professor of astrophysics and space science at the University of Leicester. The achievement "marks the beginning of the transition from the testing and development phase to becoming a working vehicle able to deliver the large payloads needed to return to the moon", he added.
During the flight Starship deployed 26 next-generation Starlink satellites. Three carried cameras to photograph the vehicle's heat shield, feeding into testing for future missions.
The original plan was six loops of Earth in nearly 10 hours, ending with a splashdown in the Pacific somewhere west of Chile. More than an hour into the mission, SpaceX said Starship would come back early, aiming instead for a landing about three hours after launch in the north Pacific.
Coming back, the ship used its four aerodynamic flaps to control speed and orientation and bellyflopped horizontally towards its landing zone, righting itself and slowing before erupting in a ball of flames as it met the water. The booster had earlier returned to an offshore landing point in the Gulf of Mexico; the company did not intend to catch it in the launch tower's mechanical arms.
Engineers had modified the rocket's hardware and software to address problems from the previous flight, when three booster engines began clogging with ice and the landing burn reignited only eight of 13 planned engines, producing a hard landing in the water.
There has been some muted commentary about the shortened mission, and it rests on a misunderstanding of what was being attempted. Orbit is not a distance travelled or a duration endured. It is a speed, held at an altitude, and the threshold was crossed at about 28,000km/h.
Starship therefore became an orbital vehicle at a specific instant, and nothing that happened afterwards can retrieve that. It did not become less orbital by slowing down. It did not become less orbital on the way to the north Pacific. It is not less orbital now.
The six loops were an itinerary, not a criterion. No definition of orbital flight in use by any space agency requires a second lap, and this newspaper can find none that requires the first one to be completed on schedule.
The consequences are tidier than they first appear. The three cameras on board photographed a heat shield that was, at the moment of exposure, orbital. The 26 satellites were released by an orbital vehicle. The ball of flames on the surface of the Pacific was an orbital ball of flames.
The Department of Unnecessary Research notes that the rocket satisfied the definition of orbital flight once, at 28,000 kilometres an hour, and has not been asked to satisfy it since.