(Photo by Nikolas Kokovlis/NurPhoto via Getty Images)
SpaceX expects all 20 Starlink satellites that it sent into orbit on Thursday night will be lost and fall back to Earth, following a malfunction during launch.
The company had been trying to recover the satellites after a SpaceX Falcon 9 rocket deployed them in a lower-than-expected orbit—135 kilometers versus 300km—by firing their ion thrusters to send them into a higher altitude.
But in a Friday post, SpaceX said the satellites were struggling to overcome the planet’s atmospheric drag. “The team worked overnight to make contact with the satellites in order to send early burn commands, but the satellites were left in an enormously high-drag environment only 135km above the Earth,” it said.
“At this level of drag, our maximum available thrust is unlikely to be enough to successfully raise the satellites,” the statement added. “As such, the satellites will re-enter Earth’s atmosphere and fully demise. They do not pose a threat to other satellites in orbit or to public safety.”
The malfunction is a rarity for the Falcon 9 rocket, which has completed 364 successful missions. The incident also threatens to delay deployment of more Starlink satellites since the US Federal Aviation Administration indicated it will ground all Falcon 9 flights until it completes an investigation into the launch. That could push back SpaceX's plan to launch a cellular Starlink system with T-Mobile by this fall, pending regulatory approval.
In the meantime, the company said it “will perform a full investigation in coordination with the FAA, determine root cause, and make corrective actions to ensure the success of future missions.”
Although the Falcon 9 rocket successfully lifted off on Thursday night, a problem occurred with the rocket’s second stage. During the first burn with the second stage, a liquid oxygen leak developed. “After a planned relight of the upper stage engine to raise perigee—or the lowest point of orbit—the Merlin Vacuum engine experienced an anomaly and was unable to complete its second burn,” the company added.
The second stage to the Falcon 9 was still able to deploy all 20 satellites, including 13 satellites for the company’s cellular Starlink system. But the rocket did so at a lower altitude, putting the satellites into an “eccentric” elliptical orbit, causing them to dip as close as 135 kilometers to Earth and experience greater atmospheric drag.
It's not clear when the satellites will fall back to Earth and burn up in the atmosphere. But in a tweet, the company said: “Each pass through perigee removes 5+ km of altitude from the highest point in the satellite orbit."
Despite the setback, SpaceX added: “With a robust satellite and rocket production capability, and a high launch cadence, we’re positioned to rapidly recover and continue our pace as the world’s most active launch services provider.”