SpaceX’s Starlink loses satellite after rare orbital anomaly, highlighting the risks of mega-constellations

SpaceX’s Starlink has lost communication with one of its satellites after a rare in-orbit failure, adding another real-world data point to the growing challenge of managing massive satellite fleets in low Earth orbit.

The incident occurred on December 17, 2025, when Starlink reported that satellite 35956 experienced an anomaly while operating at approximately 418 kilometers (260 miles) above Earth. Contact with the spacecraft was lost shortly afterward.

In a post on X, Starlink said, “On December 17, Starlink experienced an anomaly on satellite 35956, resulting in loss of communications with the vehicle at 418 km. The anomaly led to venting of the propulsion tank, a rapid decay in semi-major axis by about 4 km, and the release of a small number of trackable low relative velocity objects. SpaceX is coordinating with the @USSpaceForce and @NASA
to monitor the objects. The satellite is largely intact, tumbling, and will reenter the Earth’s atmosphere and fully demise within weeks. The satellite’s current trajectory will place it below the @Space_Station, posing no risk to the orbiting lab or its crew.”

Engineers later confirmed that the anomaly caused the satellite’s propulsion tank to vent. That event triggered a rapid drop in its orbit, shrinking its semi-major axis by roughly four kilometers and releasing a small number of slow-moving debris fragments that can be tracked from the ground. SpaceX said it is working closely with the U.S. Space Force and NASA to monitor the debris and the satellite’s descent.

The spacecraft remains intact but unstable, tumbling as atmospheric drag pulls it lower. Starlink said the satellite’s orbit sits well below the International Space Station, removing any risk to the ISS or its crew. No threat to people or property on the ground has been identified, with the company expecting the satellite to burn up completely during reentry.

Reuters first reported the anomaly on December 18, with similar coverage appearing across outlets including Yahoo Finance, Investing.com, and Sky News. Each echoed SpaceX’s position that the event poses no danger beyond the controlled loss of the vehicle itself.

The failure stands out mainly because of its context. Starlink now operates the largest satellite constellation ever deployed, with more than 6,750 active satellites delivering broadband service to over six million customers worldwide. That scale has reshaped global connectivity, especially in remote regions, while quietly raising the stakes for space traffic management.

Individual satellite failures remain uncommon, though they are no longer surprising at this size. Starlink spacecraft are designed for a lifespan of about five years and typically operate at an altitude of about 550 kilometers, where natural drag allows for eventual deorbiting. The company’s “demisability” design philosophy aims to ensure satellites disintegrate during reentry, reducing the chance of debris reaching the surface.

Past setbacks show how external forces can still overwhelm careful planning. In 2022, a geomagnetic storm increased atmospheric density, resulting in the loss of dozens of newly launched Starlink satellites. In 2024, a Falcon 9 upper-stage issue left multiple satellites stranded in decaying orbits. Earlier this year, SpaceX proactively deorbited older Starlink models after spotting potential reliability concerns.

In its latest update, SpaceX said teams are investigating the root cause of the anomaly and rolling out software changes across the fleet where needed. The company framed the incident as contained, with no impact on customer service, thanks to built-in redundancy across the network.

As solar activity continues to rise during Solar Cycle 25, atmospheric drag events are expected to become more frequent at lower altitudes, like 418 kilometers. That reality puts extra pressure on operators running mega-constellations to track, predict, and respond to failures quickly.

For now, the loss of satellite 35956 appears to follow the playbook SpaceX has long promised: fast identification, coordinated tracking, and a natural reentry that leaves nothing behind. It is a reminder that even with thousands of satellites overhead, space remains an unforgiving environment where scale amplifies both success and risk.