Practices—such as leaving rocket bodies in LEO, operators maneuvering their satellites without sharing trajectory predictions or coordinating with other active satellites, and countries conducting anti-satellite tests—have heightened the risk of collision, necessitating improvements in space-traffic coordination. Conventional methods typically observe objects only a limited number of times per day, causing large uncertainties in orbital predictions, further compounded by volatile space weather.

Stargaze delivers a several-order-of-magnitude increase in detection capability compared to conventional ground-based systems. Stargaze uses data collected from nearly 30,000 star trackers, each of which makes continuous observations of nearby objects, resulting in approximately 30 million transits detected daily across the fleet.

The system autonomously detects observations of orbiting objects and are then aggregated to generate accurate orbit estimates and predictions of position and velocity for all detected objects in near real-time. These predictions integrate into a space-traffic management platform that identifies potential close approaches between objects in space and generates Conjunction Data Messages (CDMs). To fully realize the utility of such frequent observations, SpaceX developed this system to provide conjunction screening results within minutes, compared to the current industry standard of several hours.

To maximize safety for all satellites in space, SpaceX will be making Stargaze conjunction data available to all operators, free of charge, via its space-traffic management platform. This platform has been in a “closed beta” with over a dozen participating satellite operators, allowing low-latency ephemeris sharing and conjunction screening. Starting this spring, operators that submit ephemeris (trajectory predictions) to the platform will also receive CDMs against Stargaze data, in addition to ephemeris from other participating operators. This ensures that operators have low-latency access to the best available data for conjunction assessment.

Stargaze already has a proven track record in its utility for space safety. In late 2025, a Starlink satellite encountered a conjunction with a third-party satellite that was performing maneuvers, but whose operator was not sharing ephemeris. Until five hours before the conjunction, the close approach was anticipated to be ~9,000 meters—considered a safe miss-distance with zero probability of collision. With just five hours to go, the third-party satellite performed a maneuver which changed its trajectory and collapsed the anticipated miss distance to just ~60 meters. Stargaze quickly detected this maneuver and published an updated trajectory to the screening platform, generating new CDMs which were immediately distributed to relevant satellites. Ultimately, the Starlink satellite was able to react within an hour of the maneuver being detected, planning an avoidance maneuver to reduce collision risk back down to zero.

With so little time to react, this would not have been possible by relying on legacy radar systems or high-latency conjunction screening processes. If observations of the third-party satellite were less frequent, conjunction screening took longer, or the reaction required human approval, such an event might not have been successfully mitigated.

While Stargaze embodies a major improvement to the ability of any operator to fly safely, it is imperative for operators to frequently share ephemeris of their own fleets. This is particularly true for operators with maneuvering vehicles. While Stargaze can detect maneuvers more quickly than any other system in use today, the most definitive source of satellite trajectories should be provided by operators themselves, allowing deconfliction and minimizing collision avoidance maneuvers. Starlink ephemeris is updated and shared publicly every hour, and all other operators should do the same. An appropriate analogy is commercial aviation: there are hundreds of thousands of flights of aircraft daily, but they are able to avoid collisions because they broadcast their location and flight plan to other aircraft. Similarly, spacecraft operators should follow this minimal standard of sharing their predicted trajectory.

By providing this ephemeris sharing and conjunction screening service free of charge, we hope to motivate operators to take similar steps towards ephemeris sharing and safe flight.