Celestrak Socrates

Celestrak’s source of conjunction data

I figured out where the conjunction information available in Celestrak’s visualization comes from. SOCRATES (Satellite Orbital Conjunction Reports Assessing Threatening Encounters in Space) is a Celestrak service that provides information on upcoming conjunctions.

It basically works by calculating potential conjunctions between satellites and all other bodies using AGI’s Systems Tool Kit (STK) Conjunction Analysis Tool (CAT). The data is updated 3 times a day, and the visualization relies on a CSV file provided by Celestrak.

Note that SOCRATES provides a search tool that lets you query that data and save searches. I just performed a search for my favorite man-made satellite, the ISS. It looks like debris from COSMOS 1408, the target of Russia’s ASAT test on Nov 15th, 2021, remains the main threat to the ISS. LeoLabs’s medium page has an in-depth analysis of that ASAT test and its fallout.

I also just read their most recent post, which contains amazing news: OneWeb is now a customer of LeoLab’s Collision Avoidance service! So the 3 largest satellite constellations (SpaceX, OneWeb, and Planet) are now relying on LeoLabs for SSA, making it so roughly 60% of all operational satellites in LEO rely on LeoLabs data for their safety. The post also contains good technical details about the service. I learned that LeoLabs relies on SpaceTrak’s and customer’s data to power their service, in addition to the data provided by their network of phased array radars.