With each flight test, Starship has flown further and completed more milestones. On this flight, Elon Musk’s company is focused not just on reaching an orbital trajectory but controlling the Super Heavy booster and Starship spacecraft as they reenter the atmosphere. The controlled re-entries will help SpaceX reach its ultimate goal of flying both, which are collectively known as Starship, back to the launch site so they can be reused. The company reuses its Falcon 9 rocket booster, but not the second stage. Starship is intended to be fully reusable.

On Thursday’s test flight, the booster and spacecraft separated successfully nearly three minutes after liftoff. The booster then flew back toward a designated spot in the Gulf of Mexico, fired 13 of its engines to slow itself down and landed softly in the water as part of a demonstration of how it would land back at its launch site in the future.

“Ideally, we expect Starship’s reentry to improve on each flight thanks in part to this wealth of new data,” SpaceX’s Jessie Anderson said during the company’s broadcast of the mission. “But if getting to space is hard, returning from space is even harder.”

NASA is paying close attention to the development of Starship, which is at the center of the space agency’s flagship moon campaign, known as Artemis. In 2021, the space agency awarded SpaceX a $2.9 billion contract to use the vehicle to fly astronauts to the surface of the moon. Since then, SpaceX won another contract, valued at just over $1 billion, for another crewed lunar landing.

To get to the moon, however, Starship’s propellant tanks need to be refueled by a fleet of tanker spacecraft that would launch in succession and dock with the spacecraft in low Earth orbit, a complicated task that has never been achieved before.

At the moment, NASA hopes to use Starship to land humans on the moon for the first time since the last of the Apollo missions, in 1972, by late 2026. But that timeline is uncertain given the amount of development SpaceX must complete to ensure that Starship is safe for human spaceflight. The delay is also because of concerns about the heat shield of the spacecraft, called Orion, that would fly the crews from the moon back to Earth.

NASA has also awarded Blue Origin, the space venture founded by Jeff Bezos, a contract to build a spacecraft to land astronauts on the moon. A company official told CBS’s “60 Minutes” that it intends to land a variant of its lunar lander designed to carry cargo, but not humans, on the moon next year. (Bezos owns The Washington Post.)

Since Starship’s last flight, in March, the company said, “several software and hardware upgrades have been made to increase overall reliability and address lessons learned from flight 3.”

That test mission made it to space, and the spacecraft separated successfully and traveled more than halfway around the globe.

But as its engines shut down and it began coasting, “the vehicle began losing the ability to control its attitude” or its orientation, the company said. It continued along its normal trajectory, but the “lack of attitude control” affected the reentry and the spacecraft saw “much larger than anticipated heating on both protected and unprotected areas.” The spacecraft is coated with heat shield tiles to protect it from the enormous temperatures generated during reentry.

Eventually, the spacecraft burned up 40 miles above the Indian Ocean, some 49 minutes into the flight.

Despite the failure, the flight demonstrated significant progress from its first test flight, in April 2023, when several of the main engines failed during liftoff and more failed as it ascended. The force of the rocket blew up its launchpad and sent debris flying into the Texas shoreline. That triggered a lawsuit from environmentalists, who are concerned about the massive rocket’s impact on the surrounding area.

For the second flight, SpaceX installed a water deluge system on its pad, which dampened the blast, and made upgrades to the rocket’s engines. The vehicle made it through stage separation, and the upper-stage engines fired as well. But as the booster started to ignite 13 of its engines to fly the rocket back to Earth, one engine failed, “quickly cascading to a rapid unscheduled disassembly” — the phrase SpaceX uses to describe the loss of a vehicle. The spacecraft was lost after a leak led to a fire, and its autonomous onboard flight termination system destroyed the vehicle.

This is a developing story that will be updated.