SpaceX has called off its eighth Starship test flight from Texas over an unspecified issue on the rocket system's core ship, delaying the launch for at least 24 hours.
During the countdown, SpaceX was required to hold at T-40 seconds as flight controllers worked to solve an issue with the Super Heavy booster.
Details of the problem were not disclosed.
The launch team held for several minutes at T-40 seconds before the countdown clocked briefly restarted, signalling the flight would go ahead.
However, a "late breaking issue with the ship" paused lift-off again and the test was aborted.
The company did not officially say when it would try again.
SpaceX CEO Elon Musk said there's "too many questions marks" about the flight.
"Best to de-stack, inspect both stages and try again in a day or two," he wrote on X.
Rocket assembled later than usual
SpaceX did not share exactly what the issues were that led engineers to wave off the eighth launch attempt.
However, the company only stacked the Starship upper-stage aircraft atop the Super Heavy Booster on the morning of the launch, which is later than usual.
SpaceX's Dan Huot said the company waited to stack the rocket system in an effort to continue chasing the goal of making Starship as nimble as possible.
"We really want to get to a point where we can fly rapidly, fly as quickly as possible," Huot said.
"And so this is definitely a case to try and push that forward."
He also said SpaceX did not conclude a "wet dress" rehearsal — a ground test where engineers fill the rocket with fuel and practice for launch.
[live moment]What were the engineering goals for this test?
The company said its eighth launch would target new objectives not reached on the previous test, including:
- Starship's first payload deployment of four Starlink simulators
- Multiple re-entry experiments geared towards returning the upper-stage to the launch site for catch
- The launch, return and catch of the Super Heavy booster, which has upgraded avionics
What happened to the seventh flight test?
The seventh flight test took place on January 16 and was considered a partial success.
SpaceX successfully caught the rocket's giant first-stage booster (Super Heavy) with the "chopstick" arms of the Starbase launch tower as planned.
However, the rocket's upper-stage plan went awry.
It was meant to deploy a payload — 10 mock-ups of Starlink internet satellites — circle much of the globe, and then splash down in the Indian Ocean.
That didn't happen. Instead, the upper-stage broke apart and exploded over the Atlantic Ocean about 11 minutes into the flight due to a propellant leak.
To ensure the eighth flight test goes to plan, the company said they've made "several hardware and operational changes to increase the reliability of the upper-stage".
What's the point of these test flights?
The Starship rocket is designed to eventually send astronauts to the Moon and beyond.
The rocket also plays a key role for NASA. It's the vehicle that the space agency has selected to carry astronauts on the final leg of their trip to the Moon during a mission called Artemis III. It's currently planned to take place in 2026.
Starship's debut flight was in April 2023.