SpaceX’s Falcon 9 rocket suffered a rare anomaly Thursday evening (July 11).
The incident occurred during the launch of SpaceX’s Starlink internet satellites from Vandenberg Space Force Base in California. The Falcon 9 performed well initially; its two stages separated on time and the first stage descended to land on a drone ship about eight minutes after liftoff as planned.
But the rocket’s upper stage, which was carrying 20 Starlink spacecraft into low Earth orbit, encountered a problem, according to SpaceX founder and CEO Elon Musk.
The upper stage restart to raise perigee resulted in an engine RUD for reasons currently unknown. The team is reviewing the data tonight to understand the root cause. The Starlink satellites have been deployed, but perigee may be too low for them 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. The team is reviewing the data tonight to understand the root cause. Starlink satellites have been deployed, but perigee may be too low for them to raise orbit. We’ll know more in a few hours,” Musk said via X about two hours after liftoff.
“RUD” is short for “rapid unscheduled disassembly,” a term SpaceX uses to refer to an explosion or disintegration. (Perigee, in case you were wondering, is the point in an object’s orbit where it is closest to Earth.)
An hour after Musk’s post, SpaceX provided 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 deployed to a lower orbit than planned. SpaceX has made contact with 5 of the satellites so far and is attempting to return them to orbit using their ion thrusters,” the company wrote.
In response to the post, Musk said the effort “probably won’t work, but it’s worth a try.”
The Falcon 9’s upper stage, which is powered by a single Merlin engine, looked a little odd on this flight, for what it’s worth. SpaceX’s webcast of the launch showed a buildup of fluffy white ice near the engine as it fired up into space — an unusual sight, which could indicate a propellant leak. This is just speculation, though; neither SpaceX nor Musk have said anything about the ice yet.
The Falcon 9 is the most prolific rocket currently flying, with 69 launches to its credit as of 2024. It is known for its reliability; the Falcon 9 has suffered only one total in-flight failure in its storied history, which occurred during the launch of a robotic Dragon cargo capsule to the International Space Station (ISS) in June 2015.
The Falcon 9 is also designed to carry humans. It has launched 13 crewed missions to date, nine of which have sent astronauts to the ISS for NASA. It’s not yet clear how Thursday’s incident will affect the rocket and its manifest. SpaceX will first have to figure out exactly what happened and how to fix the problem.
Thursday’s launch launched 20 Starlink satellites, 13 of which can beam signals directly to cellphones. Most Falcon 9 missions these days serve Starlink’s giant and ever-expanding megaconstellation, which currently includes more than 6,100 operational satellites; 49 of the 69 Falcon 9 launches so far in 2024 have been dedicated Starlink missions.
