SpaceX has completed a record-breaking test of a Starship booster and rolled a newer Super Heavy prototype to the launch pad just hours apart.
Almost six weeks after SpaceX began Super Heavy Booster 7’s static fire test campaign, the company has broken new ground by simultaneously igniting seven Raptor engines at once. A matter of hours later, confirming SpaceX CEO Elon Musk’s plans in real time, the company transported a second Super Heavy prototype (Booster 8) from the factory to the launch pad, where it joined Booster 7.
According to Musk, those rockets will soon switch places, ensuring that no time is wasted while SpaceX continues to gradually work towards Starship’s first orbital launch attempts.
Booster 7 kicked off the most important stage of its flight qualification process on August 9th and 11th with two back-to-back static fires, each igniting just one of 20 installed Raptor engines. Both appeared to be successful and SpaceX returned B7 to its Boca Chica, Texas factory, reinstalled a full set of 33 engines, and sent the Super Heavy back to the launch pad two weeks later.
On August 31st, SpaceX attempted to ignite three of Booster 7’s 33 Raptors. One engine failed to ignite but the others did not, resulting in a mostly successful two-engine test. Over the next two weeks, SpaceX performed several ignition-free ‘spin-prime’ tests, two of which appeared to spin up all 33 engines without causing an explosion. Finally, SpaceX telegraphed its next major goal with a seven-engine spin-prime test on September 16th and another (albeit with a slightly different set of engines) on September 19th.
Shortly after the second seven-engine spin-prime, SpaceX refilled Booster 7 with propellant, went back through the same procedures, and ignited the same seven engines for about five seconds. No obvious issues arose and Musk later implied that the test went well. It set a new record for the largest number of Raptors simultaneously ignited on a single prototype and likely also broke the record for most thrust produced by a vehicle tested at Starbase.
If all seven upgraded Raptor V2 engines were operating at full throttle, they could have briefly produced more than 1600 tons (~3.6M lbf) of thrust – roughly equivalent to two Falcon 9 boosters. Measuring about 69 meters (~225 ft) tall and 9 meters (~30 ft) wide, Super Heavy will be the most powerful liquid rocket booster ever tested once it ignites as few as 20 of its 33 engines at full thrust.
In an increasingly rare update, Musk revealed that SpaceX will once again return Booster 7 to Starbase’s factory for mysterious “robustness upgrades” after the latest round of testing. Musk doesn’t seem to think that those upgrades will take very long, and anticipates that Starbase’s “next big test” will be the first complete wet dress rehearsal of a fully-assembled two-stage Starship, followed by Super Heavy’s first 33-engine static fire test, “in a few weeks.”
More likely than not, each step of that process will take multiple attempts and uncover issues that will then need to be corrected and verified over the course of several months. But with Starship 24 having already completed a full six-engine static fire, there’s a small chance SpaceX will find itself with a fully-stacked Starship that is more or less ready for its first orbital launch attempt by the end of October.
In the meantime, after Booster 7 returns to the factory, Booster 8 – finally complete after a relatively slow six-month assembly – will kick off basic proof testing at SpaceX’s South Texas orbital launch site. SpaceX wasted no time preparing for that swap and transported Booster 8 to the pad just seven hours after Booster 7’s seven-engine static fire. If things move more smoothly than they did with B7, it’s possible that B8 will complete proof testing and be ready to head back to the factory for Raptor installation by the time B7’s upgrades are finished – a very efficient transition if it works out that way.