Up to 40 of the satellites launched by Elon Musk's Starlink last week have already been or will be lost due to a geomagnetic storm.
SpaceX's Falcon 9 rocket deployed the 49 satellites last week to bolster Starlink's internet capabilities in an orbit 210km above Earth.
However the majority were "significantly impacted" by the storm just a day later, with a number having already re-entered the Earth's atmosphere.
"These storms cause the atmosphere to warm and atmospheric density at our low deployment altitudes to increase," the company said.
"In fact, onboard GPS suggests the escalation speed and severity of the storm caused atmospheric drag to increase up to 50 percent higher than during previous launches."
In an attempt to weather the storm, the Starlink team put the satellites into 'safe-mode', during which they fly edge-on to try and minimise drag.
The satellites are launched into lower orbits so "in the very rare case" the satellites fail, they quickly deorbit and are absorbed back into the atmosphere. That's what's now happened.
"Preliminary analysis show the increased drag at the low altitudes prevented the satellites from leaving safe-mode to begin orbit raising manoeuvres, and up to 40 of the satellites will re-enter or already have re-entered the Earth’s atmosphere," Starlink said.
"The deorbiting satellites pose zero collision risk with other satellites and, by design, demise upon atmospheric re-entry - meaning no orbital debris is created and no satellite parts hit the ground."
Starlink provides fast internet for areas of the planet that struggle to get wired fibre broadband, including rural New Zealand.
The company is currently working to provide internet access for Tonga after its sea cable was damaged by the recent Hunga Tonga-Hunga Ha'apai volcano eruption.
SpaceX has launched more than 2000 Starlink satellites into orbit, out of which nearly 1900 are functioning.