Starship Explodes During Test Flight: What to Know About SpaceX’s Powerful Rocket

The 394-foot-tall Starship, the largest rocket ever built, flew for about four minutes on April 20

The Starship rocket stands on its launch pad
SpaceX's Starship is the tallest and most powerful rocket ever built. PATRICK T. FALLON / AFP via Getty Images

On Thursday, the most powerful rocket in the world exploded minutes into a test flight, after launching from Boca Chica, Texas.

Called Starship, the SpaceX rocket took off around 9:33 a.m. Eastern time and made it about four minutes into its flight. But when it came time for the Starship spacecraft to separate from the Super Heavy first stage booster, the two parts—still connected—exploded into smoke.

Though Starship’s test flight did not get completed, it did avoid a worst-case scenario of exploding on the launchpad. Elon Musk, the company’s CEO, had previously cautioned that expectations for the launch, which was originally scheduled for Monday but postponed due to a pressurization system issue, should be “low.” Now, engineers can make tweaks to other, nearly finished prototype Starships based on the outcome of this test, writes the New York Times’ Kenneth Chang.

“With a test like this, success comes from what we learn,” SpaceX wrote in a tweet. “Today’s test will help us improve Starship’s reliability as SpaceX seeks to make life multi-planetary.”

SpaceX Explosion: Starship spacecraft explodes shortly after launch

The company hopes its Starship rocket will one day be used to fly astronauts and cargo to Earth orbit and eventually carry humans to the moon and Mars. It consists of the Starship upper stage spacecraft and the Super Heavy first stage booster—collectively referred to as Starship—and together, the stack of these two parts stands 394 feet tall. Starship is the largest rocket in the world, and it is powered by more thrust than any other in history.

Once it has passed the necessary testing, Starship could serve a variety of purposes. NASA already plans to use the spacecraft as part of the Artemis program. During the Artemis 3 mission, which aims to land humans on the moon for the first time in more than 50 years, astronauts will fly to lunar orbit in NASA’s Orion capsule then travel in Starship between Orion and the moon’s surface.

SpaceX could also use Starship to carry satellites for Starlink, its satellite-based internet service. But in the long-term, Musk is eyeing the Red Planet: He wants Starship to take people to live in a Martian colony, according to Time’s Jeffrey Kluger.

Like Musk’s lofty plans for Starship, the rocket itself is ambitious. “It’s a very complex machine; it has so many different components,” Paulo Lozano, director of MIT’s space propulsion laboratory, tells NPR’s Geoff Brumfiel.

The Super Heavy booster alone stands 230 feet tall, and with an impressive 33 engines, it produces almost twice the thrust of NASA’s Space Launch System moon rocket that took off in November. And the Starship spacecraft, which could hold up to 100 people, has six engines and makes up the remaining 164 feet of the system’s height, per Marcia Dunn of the Associated Press. Together, the rocket can hold more than ten million pounds of propellant.

The whole system is made of stainless steel and powered by methane fuel. Neither is a very lightweight choice, but steel is durable and methane could be collected on Mars to power the rocket, writes NPR. And both of these materials are cheap to produce or acquire.

SpaceX conducted five short test flights of just the upper-stage spacecraft between 2020 and 2021, according to Time. The fifth attempt was the first successful one, after the first four resulted in explosions or crashes. In February, the company performed a “static fire” test of its Super Heavy booster, igniting 31 of its 33 engines while it was attached to a platform, per Reuters’ Joe Skipper and Joey Roulette.

The Federal Aviation Administration gave SpaceX approval to test the whole system on Friday, write ABC News’ Meredith Deliso and Mary Kekatos.

In Thursday’s test, the complete plan was for Super Heavy to detach from the spacecraft about three minutes after launch. Then, the rocket was to use a few engines to guide itself back to Earth, falling into the Gulf of Mexico. Meanwhile, the Starship spacecraft was planned to have completed almost an entire orbit of Earth and splash down in the Pacific Ocean no more than 90 minutes after launch, according to’s Andrew Jones.

After a successful launch of the system, SpaceX intends to send the spacecraft with a crew into low-Earth orbit.

Using such a powerful rocket for a low-Earth orbit mission is rather like “using a sledgehammer to crack a nut,” Sa’id Mosteshar, director of the London Institute of Space Policy and Law, tells Time. But down the line, the rocket’s power could prove crucial to more distant space missions, provided all goes according to plan.

Editor’s Note, April 20, 2023: This article has been updated with information about the first test flight of Starship.

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