We'll see a mass migration of SpaceX Starlink satellites this year.
All Starlink broadband spacecraft currently orbiting 342 miles (550 kilometers) or so above Earth — about 4,400 satellites — will descend to an altitude of roughly 298 miles (480 km) over the course of 2026.
"As solar mininum approaches, atmospheric density decreases, which means the ballistic decay time at any given altitude increases — lowering will mean a >80% reduction in ballistic decay time in solar minimum, or 4+ years reduced to a few months," Nicolls wrote in his X post. "Correspondingly, the number of debris objects and planned satellite constellations is significantly lower below 500 km, reducing the aggregate likelihood of collision."
Solar activity waxes and wanes on an 11-year cycle. We likely just passed through the maximum phase of the current one, known as Solar Cycle 25. (Scientists have been tracking these cycles diligently since 1755, when the numbering system began.) The next solar minimum is expected in 2030 or thereabouts.
As Nicolls noted, the atmospheric changes wrought by solar activity are of great interest and importance to satellite operators. An active sun causes a thicker atmosphere, which increases frictional drag on spacecraft and brings them down faster. Low solar activity has the opposite effect.
The downward migration in 2026 involves roughly half of SpaceX's Starlink megaconstellation, which currently consists of nearly 9,400 operational spacecraft (though that number is always growing). The fleet is highly reliable; there are just two dead Starlinks currently in orbit, according to Nicolls.
"Nevertheless, if a satellite does fail on orbit, we want it to deorbit as quickly as possible," he wrote. "These actions will further improve the safety of the constellation, particularly with difficult-to-control risks such as uncoordinated maneuvers and launches by other satellite operators."
Low earth orbit (LEO) is getting increasingly crowded these days. Starlink is the main driving factor; about two-thirds of all operational satellites belong to the megaconstellation. But other giant networks are being assembled as well. For example, China has begun building out two LEO internet constellations, each of which will each feature more than 10,000 spacecraft if all goes to plan.