Satellites Could Collide in Days If Controls Fail in Orbit

Researchers have developed a new warning system for space that shows satellites in low Earth orbit could begin smashing into each other in as little as 2.8 days if every craft loses control at once. This scenario could happen from a big solar storm or other failures, and it points to how packed the skies have become around our planet. The study comes from a team that looked at the positions of all active satellites and ran models on what might occur if operators could no longer steer them.

Background

Earth's orbit has filled up fast in recent years. Back in late 2018, there were about 2,000 satellites in low Earth orbit, the area up to 1,200 miles above the ground. By May 2025, that number jumped to at least 11,700 active ones, a 485% rise. Many of these belong to large groups like SpaceX's Starlink network, which started launching in 2019. Early 2025 counts put the total number of satellites, active and inactive, at around 15,000.

These satellites help with internet, weather tracking, and phone signals, but their numbers bring new problems. They travel at high speeds, around 17,000 miles per hour, so even a small bump can break them into thousands of pieces. Operators now dodge most close calls by firing small engines to shift paths. But if something knocks out controls across the board, like a strong solar storm flooding systems with radiation, no one could move them.

Solar storms have hit before. In 2024, one took out dozens of satellites early in their missions. Storms send charged particles that can fry electronics and make it hard to predict where objects will go next. Cyber attacks or simple glitches could also cause widespread blackouts. With 324 launches in 2025 alone, up 25% from the year before, the crowding keeps getting worse.

Key Details

The team created a tool called the Collision Realization And Significant Harm Clock, or CRASH Clock. It measures how long until the first crash in a total blackout. Their models show that by the end of 2025, this clock reads 2.8 days. There is a 30% chance a collision happens within the first 24 hours. Back in 2018, the same clock would have read 128 days, giving far more time to fix issues.

How the CRASH Clock Works

Researchers mapped out where every satellite sits in low Earth orbit. They ran thousands of tests assuming no maneuvers. The clock ticks down to the average time for the first hit. It does not predict every crash, just the start of trouble. The team thinks their number might be a bit short, but the drop from 128 days shows the real speed of change.

One big worry is Kessler Syndrome. This idea says that one crash makes debris that causes more crashes, filling orbit with junk until nothing can fly safely. No one knows the exact point where it tips over, but the CRASH Clock puts us closer than ever. Debris clouds move fast and can damage the International Space Station or crewed missions.

"It becomes impossible to estimate where objects are going to be in the future," said Sarah Thiele, lead author and astrophysics researcher at Princeton University.

Thiele pointed to solar storms as the top trigger. These events scramble navigation and power systems for days.

Other risks add up. Satellites last five to eight years on average before they fall back and burn up. Parts that survive can hit the ground. In 2023, a NASA spacecraft piece punched through a house roof in Florida. Collective odds of someone getting hurt each year now sit at 2 to 4 percent and climb with more junk.

What This Means

A CRASH Clock event would not end space travel right away, but it could start a chain no one stops. First collisions would spit out debris clouds hitting more satellites. If that lasts past 2.8 days, the cascade grows. Low Earth orbit holds most internet and observation craft, so blackouts would cut global services. GPS, TV, and banking rely on these links.

Governments and companies face pressure to act. More launches mean shorter clock times unless rules change. Experts call orbits a limited resource, like fishing grounds that fill too fast. Options include better tracking, faster de-orbiting of old satellites, and limits on new ones per area.

Solar storms come every few years, and the sun peaks in activity every 11 years. The next peak nears, raising odds of a big hit. Earthquake sensors now pick up falling junk from sonic booms, helping track re-entries. Last year saw multiple satellites drop daily, often without full records on breakup or landing spots.

The study waits for full review, but its warning stands. With trends holding, the clock will shrink more. Operators plan recovery steps, but 2.8 days tests limits. Space agencies watch close calls now numbering in thousands yearly. Fixing this means talks on sharing orbits and cleaning junk before the first big failure tests the clock for real.