The flight marks a major milestone for a rocket system that may one day send people to Mars.
Three previous missions have ended with the rocket, which stands nearly 121 metres (400 feet) tall, blowing up or disintegrating, but this time Starship survived re-entry and made a controlled fall into the Indian Ocean just 65 minutes after launching from the US state of Texas.
“Despite loss of many tiles and a damaged flap, Starship made it all the way to a soft landing in the ocean!” SpaceX CEO Elon Musk wrote on X, the social media platform he owns.
“Today was a great day for humanity’s future as a spacefaring civilization!” he added.
Starship blasted off from the company’s Starbase in Boca Chica, Texas, at 7.50am (12:50 GMT), before soaring to space and coasting halfway across the globe.
It reached an altitude of nearly 211 kilometres (130 miles), travelling at more than 26,000km/h (16,000mph) before beginning its descent. A live broadcast showed parts of the spacecraft breaking off during the intense heat of reentry, and a chunk of flying debris even cracked the camera lens.
The spacecraft remained sufficiently intact to transmit data to its targeted splashdown site in the Indian Ocean.
The success of the mission marks a critical milestone in the company’s plan to develop a reusable rocket that NASA and Musk are counting on to get humanity to the moon and then Mars.
NASA has contracted a modified version of Starship for use as the final vehicle to take astronauts down to the surface of the moon under the Artemis programme and needs the company to demonstrate that it will be able to do that safely.
“Congratulations SpaceX on Starship’s successful test flight this morning!” NASA chief Bill Nelson wrote on X. “We are another step closer to returning humanity to the Moon through #Artemis — then looking onward to Mars.”
SpaceX is committed to a strategy of carrying out tests in the real world rather than in labs.
The next challenge is to develop a “fully and immediately reusable orbital heat shield,” said Musk, promising further tests as it attempts to build a reusable satellite launcher and moon lander.
Much is riding on SpaceX’s development of Starship, with NASA aiming to use it to return astronauts to the moon in 2026 in a rivalry with China, which plans to send its astronauts there by 2030. China has made several recent advances in its lunar programme, including a second landing on the moon’s far side in a sample retrieval mission.
Starship’s first launch in April 2023 exploded minutes after liftoff some 40km (25 miles) above ground, while its second attempt in November blew up after reaching space. The rocket’s third test flight in March made it much farther but broke apart during atmospheric re-entry some 64km (40 miles) above the Indian Ocean.