SpaceX is not the only company working with the US space agency. It and Blue Origin are both due to play a key role in Artemis III, currently planned for summer 2027, another demanding schedule.
The booster was supposed to return to the launch tower about six and a half minutes after liftoff and be caught by the tower's mechanical arms, nicknamed chopsticks. Controllers sent it down at sea instead.
During the launch stream, a SpaceX spokesperson said:"Safety is always the number one priority, and we're still testing out things that we haven't done before on these vehicles, and so we are prioritising making sure that we can perform each maneuver safely.".
Elon Musk's company has caught the Super Heavy booster on three earlier test flights. This flight was its first attempt to fully recover the rocket, a step toward making Starship reusable so it can fly repeatedly and reduce costs.
The upper stage, called the Ship, has never been grabbed by the chopsticks. It reached orbit for the first time only in September.
The Ship continued toward space and was deploying 26 satellites. They will form part of the Starlink constellation, which provides high-speed internet from space.
The Ship is due to complete 14 orbits of Earth before returning to the launch tower 22.5 hours after takeoff, when a second catch may be attempted.
SpaceX was to decide whether to try to catch that stage at about 15:15 local time (21:15 GMT) on Saturday.
Before the flight, SpaceX said it would attempt a catch of the Ship only after carefully assessing the vehicle while it was in space.
If problems are detected, the rocket stage can be brought down in the ocean at several points during the flight.
Building a fully reusable rocket is a long-held ambition for SpaceX. In 2015 it became the first company to land part of a rocket vertically, using its Falcon 9 booster.
Falcon 9 rockets now fly more than 100 times a year. Reusing the bottom stage has sharply cut the cost of launch.
Blue Origin had said it would be back in action by the end of this year. A return to flight has now been delayed to early 2027.
Starship will need to make substantial progress in the coming months to meet its commitments. The pace of the rocket's development has been far slower than SpaceX had intended.