Starlink Faces Nine Conjunction Threats in Four Days, Including One HIGH-Risk Event — LEO Congestion Intensifies

WASHINGTON — March 26, 2026 — SpaceX’s Starlink constellation encountered nine conjunction threat events from March 20 to March 24, 2026, including one classified as HIGH risk, according to orbital tracking data compiled from SOCRATES and published by KeepTrack.space. The data underscores a rapidly worsening debris environment in low Earth orbit — one that researchers warn is approaching a tipping point.

One HIGH-Risk Pass at Just Nine Meters

The most serious event involved STARLINK-36658, which faced a critical close approach with the operational Chinese Earth-observation satellite SITRO-AIS 37 on March 20 at 06:23 UTC. Tracking data showed a minimum predicted range of just 9 meters and a maximum collision probability of 1.0 — a figure KeepTrack flagged as requiring independent validation given the extreme proximity.

Beyond that singular HIGH-risk event, one additional conjunction was rated MODERATE: STARLINK-1434 passing within 26 meters of fellow Starlink satellite STARLINK-32609 later the same day. Seven additional encounters registered as LOW risk, involving objects ranging from decommissioned rocket body fragments to operational satellites operated by Russian, Chinese, and private operators.

All nine events occurred within the four-day window, spanning encounters with both active satellites and non-maneuverable debris — a distinction that matters. When one party in a conjunction cannot maneuver, avoidance responsibility falls entirely on the other.

144,404 Maneuvers — And Climbing

The March threat cluster arrives amid a long-term escalation in Starlink’s collision avoidance workload. According to FCC regulatory filings cited by Aerospace America, SpaceX’s satellites performed 144,404 collision avoidance maneuvers from December 2024 through May 2025 — a figure roughly 20 times higher than comparable six-month periods in 2021–22, when the constellation was still scaling up.

The pace has not slowed. Total maneuvers for calendar year 2025 reached about 300,000, a 50% jump from 2024’s full-year count of about 200,000. Researchers project that number could reach 1 million annually by 2027 as competing mega-constellations from U.S. and Chinese operators expand alongside Starlink’s.

SpaceX applies a collision probability threshold of 3 in 10 million — far stricter than the industry standard of 1 in 10,000 — meaning many of these maneuvers address encounters that most operators would not act on. Even so, with roughly 10,087 Starlink satellites currently operational, representing approximately 65% of all active LEO spacecraft, the sheer volume of close approaches is driven as much by scale as by caution.

Legacy Debris: The Unmanageable Variable

Of the nine March conjunction events, several involved non-operational objects — debris from rocket upper stages and dead satellites that can neither maneuver nor communicate. This is the variable that worries researchers most.

A January 2026 World Economic Forum report on orbital sustainability found that the LEO environment below 800 km now holds thousands of legacy objects — defunct satellites and spent rocket stages with atmospheric decay times exceeding 100 years at current solar activity levels. Unlike new satellites, these objects cannot be commanded to avoid close approaches. The burden of avoidance falls entirely on the operational fleet.

Research consensus holds that debris prevention rules alone — including the FCC’s updated five-year deorbit mandate for U.S.-licensed satellites — cannot stabilize the environment. Without active removal of existing large legacy objects, models project a self-sustaining cascade of collisions generating ever-smaller, untrackable fragments: the scenario long described as Kessler syndrome.

ESA’s ClearSpace mission, targeting its first legacy debris removal demonstration in 2026, represents the leading near-term effort. Commercial operators including Astroscale are developing rendezvous-and-capture capabilities for non-cooperative targets. However, no large-scale removal program yet exists.

Altitude Lowering as a Near-Term Hedge

SpaceX has taken its own mitigation step for 2026: lowering approximately 4,400 Starlink satellites from roughly 550 km to 480 km altitude. At the lower orbit, atmospheric drag accelerates passive deorbit timelines for any failed satellite from years to months — reducing the window during which a dead spacecraft poses a conjunction risk to others.

The move comes as the post-peak phase of Solar Cycle 25 brings gradually declining solar activity, reducing atmospheric density at higher altitudes and slowing natural decay. By descending to 480 km, SpaceX calculates the collision risk reduction at more than 80% for affected satellites compared to the higher shell.

The measure does not, however, address legacy debris at other altitudes, nor the growing density of competing constellations at 500–600 km where multiple operators have filed for orbital slots.

The Broader Picture

Nine conjunction events in four days is not, by itself, an anomaly. Tracking systems process hundreds of thousands of conjunction assessments every 72 hours across the full LEO population. What makes this week notable is the combination: one event in the highest risk category, multiple encounters involving non-maneuverable debris, and a backdrop of accelerating maneuver rates that analysts describe as unsustainable without coordinated international action on both new launch practices and active debris removal.

For now, SpaceX’s autonomous avoidance systems — which execute maneuvers without ground-controller involvement when certain thresholds are crossed — continue to keep Starlink’s collision record clean. No Starlink-to-Starlink or Starlink-to-third-party collision has occurred to date. But researchers note that a 10% or greater annual collision probability for large constellations is not a distant theoretical risk — it is a present-day operational condition.

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Sources

• KeepTrack.space — SpaceX Brief, March 2026 — SOCRATES conjunction data for Starlink
• Aerospace America (AIAA), “Heavy Traffic Ahead,” 2025 — SpaceX FCC filing data on avoidance maneuvers
• World Economic Forum, Clear Orbit, Secure Future, January 2026 — LEO debris environment analysis
• Space.com, “SpaceX lowering orbits of 4,400 Starlink satellites,” January 2026 — altitude reduction plan
• Space Intel Report — SpaceX Starlink collision maneuver statistics, 2024–2025