SpaceX Falcon 9 second stage fails leaving Starlink satellites in wrong orbit

An unusual build up of ice on the second stage of the Falcon 9 that launched the Starlink 8-3 mission. Image: SpaceX.

SpaceX suffered its first in-flight failure of a Falcon 9 rocket since 2015, leaving 20 Starlink satellites in a perilously low orbit. SpaceX founder Elon Musk said it was unclear if the spacecraft could be saved using onboard ion thrusters.

SpaceX’s 70th orbital launch of the year, designated Starlink 9-3, initially appeared to go well after lifting off from Vandenberg Space Force Base Thursday night at 7:35 p.m. PDT (10:35 p.m. EDT, 0235 UTC). But during the burn of the Falcon 9’s second stage an unusual amount of ice was seen building up around the Merlin Vacuum engine in camera views from the rocket.

About an hour after satellite deployment, Musk posted on his social media platform X: “Upper stage restart to raise perigee resulted in an engine RUD [Rapid Unscheduled Disassembly] for reasons currently unknown. Team is reviewing data tonight to understand root cause.”

The one-second burn of the second stage to circularise the orbit was planned to occur 52 minutes and 20 seconds after liftoff.

As to the fate of the rocket’s payload, Musk added: “Starlink satellites were deployed, but the perigee may be too low for them to raise orbit. Will know more in a few hours.”

The batch of 20 Starlink satellites included 13 that feature the direct to cellphone capabilities. SpaceX said it had managed to make contact with five of the satellites and was attempting to raise their orbits. Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics, who maintains a space flight database, predicted the satellites were probably in a 295 by 138 km orbit. The intended deployment orbit was 296 x 286 km.

“We’re updating satellite software to run the ion thrusters at their equivalent of warp 9,” Musk said in social media update. “Unlike a Star Trek episode, this will probably not work, but it’s worth a shot. The satellite thrusters need to raise orbit faster than atmospheric drag pulls them down or they burn up.”

The last failure of a Falcon 9 rocket in-flight occurred on June 28, 2015, when a Dragon cargo resupply mission ended 139 seconds into flight. Another Falcon 9 exploded on the launch pad at Cape Canaveral during fueling operations for a pre-flight static test fire on Sept. 1, 2016, destroying an Israeli communications satellite and causing extensive damage to Space Launch Complex 40.

A stack of SpaceX Starlink satellites, which included the first six featuring Direct to Cell capabilities. The batch launched on the Starlink 7-9 mission, which lifted off from Vandenberg Space Force Base on Jan. 2, 2024. Image: SpaceX

The Falcon 9’s first stage booster for the Starlink 9-3 mission, tail number B1063 in the SpaceX fleet, was flying for a 19th time. Its previous launches included NASA’s Double Asteroid Redirection Test (DART) spacecraft, the Transporter-7 rideshare mission and 13 batches of Starlink satellites.

A little more than eight minutes after liftoff, B1063 landed on the SpaceX droneship, ‘Of Course I Still Love You.’ This was the 96th landing on OCISLY and the 329th booster landing to date.