Broadband Satellite ISP Starlink Prep Free Stargaze Data to Avoid Space Collisions

The Starlink service from SpaceX, which operates a mega constellation using thousands of ultrafast broadband internet satellites in Low Earth Orbit (LEO) for the UK and globally, has revealed that they’re about to start making data from their Space Situational Awareness (SSA) system, called Stargaze, available for free to other satellite operators.

Starlink currently has around 9,600 satellites in Low Earth Orbit (c.6,150 are v2 / GEN2 variants) – mostly at altitudes of between c.340-525km. Residential customers in the UK usually pay from £35 a month for the ‘Residential 100Mbps’ unlimited data plan (kit price may vary due to different offers), which also promises uploads of c.15-35Mbps and low latency connectivity. Faster packages exist at greater cost, while more restrictive (data capped) options also exist for roaming users (e.g. £50 per month for 100 GigaBytes of data).

However, one of the growing concerns with such large constellations is that they may increase the risk of a Kessler Syndrome style event, which is a theoretical situation in which a runaway chain reaction of collisions in low Earth orbit (LEO) creates a cloud of space debris density. This then damages many other satellites and potentially renders Earth’s orbit unusable for satellites and future space missions / rockets.

SpaceX thus operates a novel Space Situational Awareness (SSA) system, called Stargaze, which they say enhances the safety and sustainability of satellite operations in LEO. The system 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). The system can provide conjunction screening results within minutes, compared to the current industry standard of several hours.

Such systems are necessary because there are all sorts of hazards for Earth’s increasingly crowded satellite space to consider. Practices — such as leaving rocket bodies in LEO, operators manoeuvring their satellites without sharing trajectory predictions or coordinating with other active satellites, and countries conducting anti-satellite tests — have all heightened the risk of collision, necessitating improvements in space-traffic coordination.

The problem is that 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. So in order to address this, Starlink has gone a step further by announcing that its screening data will be made available to the broader satellite operator community “free of charge in the coming weeks.”

Starlink Statement

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 manoeuvre which changed its trajectory and collapsed the anticipated miss distance to just ~60 meters. Stargaze quickly detected this manoeuvre 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 manoeuvre 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.

Despite the development and improvements of their system, SpaceX have recently become keen to encourage other satellite operators to start sharing their data on satellite trajectories and now appear to be trying to lead by example (partly because their huge network also makes them among the most vulnerable to such dangerous events).

“Starlink ephemeris is updated and shared publicly every hour, and all other operators should do the same,” said the company. “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.”