SpaceX Scrubs 8th Starship Rocket Test Flight

Starship — the spacecraft that Elon Musk says will one day take people to Mars — will try another day to carry out its eighth test flight.

This trip to space, which had been scheduled for Monday night, was to be largely a do-over of the seventh flight, which launched in January. In that test, Starship’s mammoth booster, or the bottom of the rocket, successfully returned to the launchpad, but the upper-stage spacecraft disintegrated over the Caribbean, with some debris landing on the Turks and Caicos Islands.

But an issue with the second-stage spacecraft, resulted in the postponement of Monday’s launch attempt from the company’s South Texas launchpad. During the livestream, SpaceX commentators did not offer details about what caused the launch to be called off.

In a posting on X, Mr. Musk, the chief executive of SpaceX said there were “too many question marks about this flight” and cited low pressure in one particular system.

He added that it was best to take the rocket off the launchpad, inspect it “and try again in a day or two.”

What is Starship?

The Starship rocket system is the largest ever built. At 403 feet tall, it’s nearly 100 feet taller than the Statue of Liberty atop its pedestal.

It has the most engines ever in a rocket booster: The Super Heavy booster is powered by 33 of SpaceX’s Raptor engines. As those engines lift Starship off the launchpad, they will generate 16 million pounds of thrust at full throttle.

The upper part, also called Starship or Ship for short, looks like a shiny rocket from science fiction movies of the 1950s, is made of stainless steel with large fins. This is the upper stage that will head toward orbit, and ultimately could carry people to the moon or even Mars.

In six tests before the seventh flight, SpaceX demonstrated that the rocket’s basic design works and the Starship can return to Earth almost intact. Over the coming year, SpaceX is looking to improve “more or less” to “reliably” and prove out other capabilities. The company is likely to receive approval from the Federal Aviation Administration for up to 25 flights this year.

What went wrong during the last flight?

The first part of the launch proceeded smoothly, with all 33 engines of the booster lifting the rocket toward space. The booster also separated properly, and the six engines of the second-stage spacecraft ignited, pushing it upward. But something went wrong, and air traffic over the Caribbean had to be diverted and delayed around the falling debris.

About two minutes into the upper stage’s flight, a flash occurred near the back of the spacecraft near one of the engines, SpaceX said. The company calls this area the “attic.”

Sensors recorded a rise in pressure indicating a leak, SpaceX said.

Two minutes later, there was another flash followed by fires in the attic, which caused all but one of the engines to shut down. Telemetry from the spacecraft ended eight minutes 20 seconds after liftoff.

SpaceX said that the probable cause was stronger than expected rhythmic oscillations. The vibrations caused leaks of propellant that could not be fully vented from the attic, leading to the fires.

SpaceX said that, according to its analysis, the self-destruct system blew up the rocket a few minutes later.

What did SpaceX change to fix the problem from the last flight?

The company said that feed lines carrying propellant to the engines were changed to reduce the oscillations. SpaceX also altered the propellant temperatures and thrust levels of the engines to avoid a repeat of the leaks.

For the rocket on this flight, SpaceX also added more vents to the attic section, and a system to purge the area of propellants in order to reduce the chance of fires.

The F.A.A. oversaw SpaceX’s investigation of what went wrong during the seventh test flight, and it issued a launch license on Friday for the eighth flight.

What else will happen during this flight?

While in space, Starship will test a new system that somewhat resembles a Pez candy dispenser. It will shoot out four dummy satellites that are similar in size and shape to spacecraft that will be deployed for SpaceX’s Starlink internet service. The dummy satellites will burn up in the atmosphere over the Indian Ocean.

The flight also includes tests that aim to improve the ability of the upper stage to survive re-entry into the Earth’s atmosphere over the Indian Ocean.

The rocket stage will pivot to a vertical orientation and simulate a landing over the water.

SpaceX will also try another catch of the Starship’s booster.

When will Starship be able to send people to space?

NASA is planning to use a version of Starship to take astronauts from lunar orbit to the surface of the moon during its Artemis III mission, currently scheduled for 2027.

But that mission could be delayed, or even canceled, if the Trump administration revamps the moon program or shifts its attention to Mars.

SpaceX will need to demonstrate high reliability of Starship before a flight with people on board takes place.

What else is going on with SpaceX?

The company continues to launch its Falcon 9 rockets from Florida and California every few days. But it has also had some recent glitches with that launcher.

During launch in February, a Falcon 9 upper stage failed to execute the usual engine burn to ensure that the rocket’s remains would splash down in the ocean. Instead, it remained in orbit. Air resistance caused it to fall gradually, and the stage re-entered the atmosphere 18 days later over Europe. No one was hurt or injured, but pieces of the rocket appear to have landed in Poland.

SpaceX encountered another problem on Sunday night when a Falcon 9 booster successfully landed on a barge in the Atlantic Ocean but then fell over.

SpaceX reported that “an off-nominal fire in the aft end of the rocket damaged one of the booster’s landing legs which resulted in it tipping over.”