SpaceX has risen to prominence on the strength of its Falcon 9 rocket, a launch vehicle that, until recently, seemed almost bulletproof. The Falcon 9 has now suffered its third launch anomaly in as many months, leading SpaceX to once again ground the rocket until engineers can understand why this weekend’s launch didn’t go entirely as planned.
The Saturday launch was a big one—the Falcon 9 sent the Crew-9 mission on its way to the International Space Station (ISS). The Dragon capsule carried only two astronauts at launch, a change necessary to accommodate Suni Williams and Butch Wilmore, who have been stuck on the ISS since they flew the ill-fated Boeing Starliner there back in June. Luckily, the rescue mission got to the ISS just fine. SpaceX’s troubles didn’t begin until the second stage tried to deorbit.
SpaceX hasn’t provided much detail on the anomaly yet, saying just that the second stage experienced an “off-nominal deorbit burn.” As a result, the vehicle splashed down in a different area of the Pacific Ocean than intended. This probably means the engine did not burn for as long as it was supposed to or didn’t produce enough thrust. SpaceX says it will restart Falcon 9 flights as soon as it understands the root cause. There will most likely be an FAA investigation, as well.
This anomaly follows another problem with the second-stage Merlin vacuum engine in July. When attempting to launch a group of Starlink satellites, an oxygen leak in a sense line caused ice to accumulate around the engine. This lowered the temperature of components and caused a “hard start” that damaged the engine. The following month, a Falcon 9 first stage tipped over after landing on one of the company’s drone ships. Both incidents triggered a brief pause in launches.
While the Dragon spacecraft made it to the ISS as planned, there may be more apprehension about this anomaly than the past two. This is starting to look like a trend, and the flight was crewed. The last two flight anomalies were cargo missions only. Hopefully, SpaceX will wrap up this investigation with its characteristic speed because there are several important, time-sensitive launches on the horizon.
On Oct. 7, SpaceX is slated to launch the European Space Agency’s Hera mission to study companion asteroids Didymos and Dimorphos, the latter of which was the target of NASA’s DART planetary defense test. Just a few days later, SpaceX will use a Falcon Heavy (which is basically three Falcon 9s in a trenchcoat) to launch NASA’s Europa Clipper mission. Both those missions have launch windows of just a few weeks, so time is of the essence.