US President-elect Donald Trump joined SpaceX CEO Elon Musk to watch the launch of a massive Starship spacecraft from the company’s rocket facilities on the Gulf Coast in Brownsville, Texas.

The 122-meter (400 ft) tall rocket, which is part of NASA’s Artemis program, blasted off from Musk’s Boca Chica manufacturing and testing complex on Tuesday. The spacecraft is designed to land astronauts on the Moon and ferry crews to Mars, and is capable of carrying up to 100 passengers when configured for humans, according to SpaceX.

Ahead of the launch, Trump wished Musk luck, posting on X: “I’m heading to the Great State of Texas to watch the launch of the largest object ever to be elevated, not only to Space, but simply by lifting off the ground.”

SpaceX was conducting the sixth test of the rocket; the first stage, called Super Heavy, was expected to fly back to its launch pad where the rocket booster is caught by a giant set of mechanical arms in a landing dock on its return to Earth. The catch was achieved for the first time during Starship’s fifth test flight in October.

However, this time SpaceX aborted the plan just minutes into the test flight for unspecified reasons. The Super Heavy booster wasn’t able to return to the launch pad and instead made a splashdown in the Gulf of Mexico, indicating that something had gone wrong.

The rest of the mission was reportedly a success. Among the objectives for the test were igniting one of the engines in space, making a visible ocean landing during the daytime, and making the booster landing faster.

Trump’s appearance at the launch signals a deepening alliance with Musk, who stands to benefit from his second term in office. SpaceX is already reaping billions of dollars in US government contracts, and is poised to clinch more.

“The founder of this century’s most innovative space company, Elon Musk, successfully used his fortune, time, and energy to help elect Donald Trump to president of the United States,” Ars Technica’s senior space editor, Eric Berger, wrote earlier this month. “It’s entirely possible that the sitting chief executive of SpaceX could be the nation’s most important adviser on space policy.”

Musk has actively supported the president-elect and has become an increasingly influential figure on his team. Last week, Trump chose Musk and entrepreneur Vivek Ramaswamy to head the Department of Government Efficiency (DOGE), a new initiative that will be tasked with reducing government waste.