SpaceX Test Fires 31 Engines on the Most Powerful Rocket Ever

SpaceX moved one step closer to its future on Thursday with a successful ground test of the engines of the most powerful rocket ever built.

The company, founded by the entrepreneur Elon Musk, conducted what is known as a static fire of Super Heavy, a massive rocket booster. Super Heavy was made to send SpaceX’s next-generation Starship vehicle toward orbit before returning to Earth.

More than 110,000 people watched a livestream broadcast by NASASpaceFlight.com, an independent space media company that has cameras monitoring the Starship test site in Boca Chica, Texas. The video feed showed clouds of vapor enveloping the launch stand when propellants started flowing into the rocket, and rings of frost forming around the rocket as the tanks filled with ultracold propellants.

Then the clouds mostly vanished when the fueling was complete — for the brief test, the tanks were not filled to the brim.

At 4:14 p.m. Eastern time, on a video feed provided by SpaceX, the engines roared to life for a few seconds and shut down, kicking up that rose clouds above the rocket and prompting masses of birds to flee the area. An update on Twitter from SpaceX indicated the test was a success, lasting as long as intended. The booster and launch stand appeared to be in good shape afterward.

On Twitter, Mr. Musk said one engine was turned off during the test and another one turned itself off. Even so, 31 of 33 engines would be enough to reach orbit during a launch, Mr. Musk said.

The static fire of the Super Heavy booster was the last big technical hurdle that SpaceX needed to accomplish before getting ready for a launch attempt. SpaceX had previously conducted static fires with up to 14 engines. Beginning in December 2020, it conducted a series of test flights of Starship prototypes several miles up to figure out the landing procedure. After several explosive failures, it succeeded in May 2021, with Starship launching and landing in one piece.

When combined, Super Heavy and Starship stand nearly 400 feet high, taller than the Statue of Liberty and its pedestal. NASA is paying SpaceX to build a version of the vehicle to carry astronauts to the lunar surface for the Artemis III and IV missions later in the decade. The spacecraft is also central to Mr. Musk’s vision of sending people to Mars along with the supplies they would need.

Last month, SpaceX conducted a “wet dress rehearsal,” filling up the tanks on both Super Heavy and Starship craft with more than 10 million pounds of liquid methane and liquid oxygen propellants. After the wet dress rehearsal, Starship was taken off the booster, which remained at the launchpad.

Thursday’s static fire test was announced on Wednesday by Gwynne Shotwell, president and chief operating officer of SpaceX, during remarks at the Federal Aviation Administration Commercial Space Transportation conference in Washington.

She said the launch attempt could occur within a month or so.

If all 33 engines had fired at full power on Thursday, the Super Heavy booster would have unleashed 17 million pounds of thrust, which would make it the most powerful rocket ever ignited. NASA’s new Space Launch System rocket, which launched for the first time in November to send the uncrewed Artemis I mission to the moon, generated 8.8 million pounds of thrust at liftoff. The Saturn V rocket used for the Apollo moon landings of the 1960s and 1970s generated 7.6 million pounds of thrust at launch.

Starship is designed to be completely reusable. The Super Heavy booster is designed to land much like the boosters of SpaceX’s current Falcon 9, the most frequently launched rocket in the world. Starship is designed to go to orbit and then return to Earth, belly-flopping through the atmosphere to slow down before pivoting to a vertical orientation for landing.

Before the rocket leaves the ground for an orbital test, SpaceX still needs to obtain a launch license from the Federal Aviation Administration, which is in charge of ensuring the safety of people on the ground.

Last June, the F.A.A. concluded that SpaceX’s launch plans would have “no significant impact” on the surrounding areas near Brownsville, Texas. But the F.A.A. required SpaceX to take 75 actions to mitigate the environmental effects, including earlier notice of launches, monitoring of vegetation and wildlife by a biologist and minimizing closures of a highway that passes by the SpaceX site.

According to Space News and CNBC, Ms. Shotwell laid out an ambitious future for Starship — ramping up for 100 flights a year, perhaps as soon as 2025. Ms. Shotwell said SpaceX hoped that it would conduct 100 launches before putting people aboard. A version of Starship is part of NASA’s Artemis III mission, to take astronauts from lunar orbit to the surface of the moon. That is currently scheduled for 2025.

SpaceX also has three private missions on its manifest for Starship, one by Jared Isaacman who previously bought an orbital trip on a Falcon 9. Yusaku Maezawa, a Japanese entrepreneur, and Dennis Tito, who was the first private individual to buy a trip to the International Space Station in 2001, have bought Starship flights to go around the moon and back.