• SpaceX launched the sixth test flight of its Starship rocket on Tuesday, its fourth in 2024.
• The uncrewed Starship took off from the company's facility near Brownsville, Texas before splashing down intentionally about an hour later in the Indian Ocean.
• SpaceX aimed to again catch the rocket's "Super Heavy" booster with its launch tower but instead splashed down the booster in the Gulf of Mexico.

SpaceX launched the sixth test flight of its Starship rocket on Tuesday, as the company looks to keep up momentum of the mammoth vehicle's development.

The rocket took off from SpaceX's private "Starbase" facility near Brownsville, Texas. There were not any people on board the Starship flight.

Starship reached space and traveled halfway around the Earth before reentering the atmosphere and splashing down in the Indian Ocean.

SpaceX had aimed to return the rocket's "Super Heavy" booster after it separated from Starship and land it on the arms of the company's launch tower. But SpaceX said during its webcast that the booster did not clear its "commit criteria" needed for the catch attempt, so the booster splashed down in the Gulf of Mexico instead.

As with each previous test flight, SpaceX is pushing development further by testing additional Starship capabilities, including this time reigniting an engine while in space and testing new elements of its heatshield.

Additionally, the evening launch time means that this was the first time Starship made a daylight splashdown in the Indian Ocean.

SpaceX typically has a cadre of VIPs to view Starship launches and, with CEO Elon Musk's close relationship with President-elect Donald Trump, the sixth flight wa no different. Trump attended the launch on Tuesday, similar to when he came to watch SpaceX's first astronaut launch in Florida in 2020 during his first administration.

Pushing the envelope

SpaceX has flown the full Starship rocket system on six spaceflight tests so far since April 2023, at a steadily increasing cadence. Its previous launch last month featured the dramatic first catch of the rocket's more than 20-story tall booster.

After the successful fifth flight, the Federal Aviation Administration confirmed that SpaceX was authorized to move forward with the sixth flight.

But, as with its previous test flights, the fifth launch was not without incidents. SpaceX management, in audio posted after the launch on social media by Musk, revealed that Starship's booster nearly missed the catch due to a timing issue with one of the rocket's subsystems.

"We were one second away from that tripping and telling the rocket to abort and try to crash into the ground next to the tower instead of [landing at] the tower — like, erroneously tell a healthy rocket to not try that catch," an unidentified person told Musk in the audio.

SpaceX did not catch the booster again. The company said on its website that it made hardware upgrades to the rocket's booster for improved redundancy and improved structural strength.

The Starship system is designed to be fully reusable and aims to become a new method of flying cargo and people beyond Earth. The rocket is also critical to NASA's plan to return astronauts to the moon. SpaceX won a multibillion-dollar contract from the agency to use Starship as a crewed lunar lander as part of NASA's Artemis moon program.

Starship is both the tallest and most powerful rocket ever launched. Fully stacked on the Super Heavy booster, Starship stands 397 feet tall and is about 30 feet in diameter.

The Super Heavy booster, which stands 232 feet tall, is what begins the rocket's journey to space. At its base are 33 Raptor engines, which together produce 16.7 million pounds of thrust — about double the 8.8 million pounds of thrust of NASA's Space Launch System rocket, which launched for the first time in 2022.

Starship itself, at 165 feet tall, has six Raptor engines — three for use while in the Earth's atmosphere and three for operating in the vacuum of space.

The rocket is powered by liquid oxygen and liquid methane. The full system requires more than 10 million pounds of propellant for launch.