SpaceX’s workhorse Falcon 9 rocket experienced a rare anomaly on Thursday evening (July 11).
The incident occurred during a launch of SpaceX’s Starlink internet satellites from Vandenberg Space Force Base in California. The Falcon 9 initially performed well, with the two stages separating on time and the first stage touching down for a landing on a drone ship about eight minutes after launch as planned.
But the upper stage of the rocket, which carried 20 Starlink spacecraft to low-Earth orbit, encountered a problem, said Elon Musk, founder and CEO of SpaceX.
Restarting the upper stage to raise perigee resulted in an engine RUD for reasons currently unknown. The team is reviewing the data tonight to determine the cause. Starlink satellites have been deployed, but perigee may be too low to raise the orbit. We will know more in a few hours.July 12, 2024
“Upper stage restart to raise perigee resulted in an engine RUD for reasons currently unknown. Team is reviewing data tonight to determine cause. Starlink satellites have deployed, but perigee may be too low to raise orbit. We will know more in a few hours,” Musk said via X about two hours after launch.
“RUD” is short for “rapid unscheduled disassembly” — SpaceX jargon for an explosion or disintegration. (Perigee, in case you’re wondering, is the point in an object’s orbit at which it’s closest to Earth.)
An hour after Musk’s post, SpaceX released more details via the company’s X account.
“During tonight’s Falcon 9 launch of Starlink, the second stage engine did not complete its second burn. As a result, the Starlink satellites were placed in a lower orbit than intended. SpaceX has made contact with five of the satellites so far and is attempting to place them in a higher orbit using its ion engines,” the company wrote.
In a response to that post, Musk said that this attempt “probably won’t work, but it’s worth a try.”
The Falcon 9’s upper stage, powered by a single Merlin engine, looked a little odd on this flight, for what it’s worth. SpaceX’s launch webcast showed a buildup of fluffy white ice near the engine as it blasted into space — an unusual sight, and one that could indicate a fuel leak. That’s just speculation, though; neither SpaceX nor Musk has yet commented on the ice.
The Falcon 9 is the most productive rocket currently flying, with 69 launches through 2024. It is known for its reliability; the Falcon 9 has suffered only one complete in-flight failure in its illustrious history, during the launch of a robotic Dragon cargo capsule to the International Space Station (ISS) in June 2015.
The Falcon 9 is also capable of carrying humans; it has launched 13 crewed missions to date, nine of which sent astronauts to the ISS for NASA. It’s unclear how Thursday’s incident will affect the rocket and its manifest; SpaceX will first have to figure out exactly what happened and how to address the problem.
Thursday’s launch sent 20 Starlink satellites into the sky, 13 of which can beam directly to cell phones. Most Falcon 9 missions today serve the massive and ever-expanding Starlink mega-constellation, which currently consists of more than 6,100 operational satellites; 49 of the 69 Falcon 9 launches so far in 2024 have been dedicated Starlink missions.