Starlink is to lower the orbits of about half its satellite constellation over the course of this year, citing safety concerns.

The change was announced by Michael Nicolls, VP of Starlink engineering at the satellite operator's parent company, SpaceX. He said the firm plans to lower all of its units that orbit at about 550 km down to roughly 480 km during 2026.

This comes after one Starlink satellite failed last month. During an incident, the sat both vented propellant, sending it tumbling out of control, and released debris. That followed claims from SpaceX that a Chinese satellite launch came within 200 meters of colliding with another of Starlink's units, although the company has not so far said that a collision caused the loss of its satellite.

Nicolls claimed that changing orbits would increase space safety in several ways.

"As solar minimum approaches, atmospheric density decreases which means the ballistic decay time at any given altitude increases – lowering will mean a >80 percent reduction in ballistic decay time in solar minimum, or 4+ years reduced to a few months," he stated.

The volume of debris and planned satellite constellations is also notably lower below 500 km, he added, which will reduce the likelihood of collisions.

Starlink's orbital migration is expected to involve about 4,400 of the more than 9,000 satellites it currently has in operation. The maneuver is being carried out in coordination with other operators, regulators, and US Space Command, the firm says.

There has been growing unease over the number of satellite launches, particularly into low Earth orbit (LEO). As well as Starlink, Amazon's Project Kuiper aims to loft over 3,000 satellites to deliver broadband from space, while China is understood to have plans to put more than 10,000 into orbit to provide its own rival services to Starlink.

With all that hardware circling the Earth at high velocity, there is a growing risk of collisions, and scientists fear that such incidents could lead to an increasing amount of debris that would render certain orbits unusable – the so-called Kessler Syndrome. Last month, The Register reported on the CRASH Clock, which estimates how long it might take before such a catastrophic collision occurs.

• Starlink satellite fails, polluting orbit with debris and falling toward Earth
• Starlink claims Chinese launch came within 200 meters of broadband satellite
• The CRASH Clock is ticking as satellite congestion in low Earth orbit worsens
• Ukraine first country in Europe to get Starlink satellite phone service

The US Public Interest Research Group (PIRG) even called on the Federal Communications Commission to halt LEO satellite launches until the environmental consequences of space pollution might be better managed.

However, SpaceX boss Elon Musk pooh-poohed the notion, agreeing with a social media poster that concern over too many satellites in orbit was a "silly narrative."

That was before last year's incident where a spacecraft attached to China's Tiangong space station was found to have small cracks in its viewport window, blamed on damage from space debris, making it unsafe to return to Earth.

In typical confrontational mode, Chinese authorities have reportedly complained to the United Nations that the rapid expansion of Starlink is contributing to safety and security concerns.

According to The Independent newspaper, Beijing called for countries to better enforce regulations on their commercial space activities. ®