With Falcon 9 grounded, SpaceX test-fires booster for next Starship flight

It's unclear yet how long SpaceX's workhorse Falcon 9 rocket will remain grounded as engineers investigate a rare launch failure last week, but the next test flight of the company's next-generation Starship vehicle appears to be on track for liftoff next month. On Monday, SpaceX test-fired the 33 Raptor engines on the Starship rocket's Super Heavy booster at the company's Starbase facility in South Texas. The methane-fueled engines fired for about eight seconds, long enough for SpaceX engineers to verify all systems functioned normally. At full power, the 33 engines generated nearly 17 million pounds of thrust, twice the power output of NASA's iconic Saturn V Moon rocket. SpaceX confirmed the static fire test reached its full duration, and teams drained methane and liquid oxygen from the rocket, known as Booster 12 in the company's inventory of ships and boosters. The upper stage for the next Starship test flight, known as Ship 30, completed the static fire of its six Raptor engines in May. During the fourth flight of Starship on June 6, SpaceX successfully guided the Super Heavy booster back to a controlled splashdown in the Gulf of Mexico east of Starbase. The ship continued into space and completed a half-lap around the planet before reentering the atmosphere for a guided propulsive splashdown in the Indian Ocean. This was the first time SpaceX succeeded in getting the booster and ship close to their targeted splashdown locations. The Super Heavy booster's on-target water landing gave SpaceX officials the confidence to attempt to recover the booster on the next flight at Starbase, where giant articulating arms—colloquially known as "chopsticks"—on the launch tower will try to catch the rocket as it slows to a hover right over the launch pad. Kathy Lueders, SpaceX's general manager at Starbase, told local residents last month that SpaceX was still considering whether to attempt a catch of the booster on the next flight. The catch concept is a bold one and is starkly different from the way SpaceX recovers Falcon 9 boosters, but SpaceX officials believe it is the best way to recover boosters for rapid reuse. Earlier this month, SpaceX released a teaser video for the next Starship flight suggesting that a booster catch was back on the table.

Full duration static fire of Flight 5 Super Heavy booster pic.twitter.com/8rF9KUdMUD — SpaceX (@SpaceX) July 15, 2024

SpaceX will also use the fifth Starship test flight to test an upgraded heat shield on the ship, or upper stage, after reentry heating damaged the vehicle during descent on its previous flight last month. Working inside a hangar a short drive from the launch pad, technicians are replacing thousands of ceramic tiles on the outer skin of Ship 30. Once that work is complete, SpaceX will stack the ship on top of the booster and may perform a full countdown rehearsal a few days before the first launch attempt, which could happen as early as August. Meanwhile, construction of a second launch pad at Starbase is underway. Construction crews have stacked the first few segments of the latticework launch tower a short distance from the existing Starship launch pad. Within a couple of years, SpaceX aims to have two active launch pads in Texas and two Starship launch sites in Florida to support a growing Starship flight rate. These Starship missions will launch Starlink Internet satellites, conduct in-orbit refueling tests, and support NASA's Artemis lunar program.

Probing the leak

While Starship preparations continue in Texas, SpaceX's Falcon 9 rocket is out of service as engineers look into the cause of an upper stage failure on a Starlink mission last week. The failure ended a streak of more than 300 successful Falcon 9 missions in a row, a world record for the launch industry. The Falcon 9's upper stage engine failed to reignite in space for a maneuver to place 20 Starlink Internet satellites into the proper orbit for deployment. The satellites separated from the rocket but at an altitude too low for the spacecraft's ion engines to overcome. All 20 satellites were expected to reenter the atmosphere within a couple of days. In an update posted on SpaceX's website Friday, the company said a liquid oxygen leak developed on the Falcon 9's upper stage. "After a planned relight of the upper stage engine to raise perigee—or the lowest point of orbit—the Merlin Vacuum engine experienced an anomaly and was unable to complete its second burn," SpaceX said. "Although the stage survived and still deployed the satellites, it did not successfully circularize its orbit, but it did passivate itself as normally performed at the end of each mission. This left the satellites in an eccentric orbit with a very low perigee of 135 km (84 miles), which is less than half the expected perigee altitude." The Federal Aviation Administration, which licenses all commercial space launches in the United States, will require SpaceX to conduct a mishap investigation before resuming Falcon 9 flights. "The FAA will be involved in every step of the investigation process and must approve SpaceX’s final report, including any corrective actions," an FAA spokesperson said. "A return to flight is based on the FAA determining that any system, process, or procedure related to the mishap does not affect public safety." The grounding of the Falcon 9 has already delayed several missions that were supposed to launch this month, including several Starlink flights, the launch of a pair of Norwegian communications satellites, and a Transporter small satellite rideshare mission. NASA and the US military rely on the Falcon 9 and Falcon Heavy rockets to boost astronauts, costly science probes, and critical national security satellites into space. It's unclear how long it will take for SpaceX to complete its investigation to the satisfaction of the FAA, but the fast cadence of Falcon 9 flights in recent months suggests it may not take long for SpaceX to introduce and test, in flight, any fixes required to resolve the problem. "SpaceX will perform a full investigation in coordination with the FAA, determine root cause, and make corrective actions to ensure the success of future missions," SpaceX said. "With a robust satellite and rocket production capability, and a high launch cadence, we’re positioned to rapidly recover and continue our pace as the world’s most active launch services provider." Two astronaut missions were slated to launch on Falcon 9 rockets late this month and in mid-August. One is a fully private mission named Polaris Dawn, which will mount the first all-commercial spacewalk in orbit, and the other will carry a crew of four to the International Space Station under contract with NASA. A Northrop Grumman commercial resupply mission to the space station was supposed to launch in early August on a Falcon 9 flight. A spokesperson for the US space agency said it regularly receives insight from SpaceX on "all items of interest about the Falcon 9 rocket." "SpaceX has been forthcoming with information and is including NASA in the company’s ongoing anomaly investigation to understand the issue and path forward," NASA said in a statement. "NASA will provide updates on agency missions including potential schedule impacts, if any, as more information becomes available."