Introducing Topics: Unified Ontology for 250+ Artifacts

Project Dyson has grown to over 250 artifacts: 140 research questions, 57 blog posts, 33 BOM items, plus validations, experiments, and organization records. Each uses ad-hoc tags in its frontmatter — "propulsion", "isru", "thermodynamics" — but until now, there was no formal taxonomy connecting them.

Today we're launching Topics, a unified ontology that defines engineering domains and topics, then resolves existing tags to them at runtime. Browse it at /topics.

The Problem: Fragmented Discovery

If you wanted to find everything related to propellant systems, you'd need to know that some artifacts use "propellant", others use "krypton", "xenon", "fuel-economics", or "propellant-transfer". Blog posts might tag "alternative-propellants" while validations use "ion-propulsion". There was no way to say "show me everything about propellant" across artifact types.

The Approach: Tag Resolution, Not Tag Replacement

Rather than migrating tags across 250+ content files, we defined a taxonomy YAML where each topic declares which legacy tags map to it:

- id: "propellant-systems"
  name: "Propellant Systems"
  legacyTags:
    - "propellant"
    - "krypton"
    - "xenon"
    - "iodine"
    - "fuel-economics"
    - "propellant-transfer"

At runtime, the ontology service builds a reverse index from every legacy tag to its topic(s). When a research question has tags: ["krypton", "propulsion"], the system resolves these to the "Propellant Systems" and "Propulsion (General)" topics — zero migration required.

What's in the Taxonomy

The ontology organizes knowledge into 13 domains with 52 topics:

Domain	Topics	Example Tags
Propulsion & Orbital Mechanics	6	ion-propulsion, station-keeping, delta-v
Materials & Manufacturing	5	thin-film, perovskite, cold-welding
Energy & Power Systems	5	photovoltaics, power-beaming, batteries
Space Environment & Protection	5	radiation, debris, thermal-management
Robotics & Autonomous Systems	4	self-replication, maintenance, autonomy
Computing & Communications	3	laser-comm, distributed-systems, ML
Mining & Resource Processing	3	asteroid-mining, ISRU, water
Swarm Architecture & Control	4	swarm-control, deployment, fleet-sizing
Membrane & Collector Design	3	membrane-dynamics, flutter, optics
Mission Design & Logistics	5	launch-strategy, supply-chain, cost-analysis
Advanced Concepts	3	matrioshka-brain, stellar-engines
Governance & Organization	3	governance, safety, non-profit
Research Methodology	3	multi-model, simulation, testing

Coverage

The bootstrap script scanned all 334 content files and found 422 unique tags. The taxonomy maps 90% of them (380/422). The remaining 42 unmapped tags are structural identifiers like phase-1, research-question, and resolution — classification labels rather than engineering topics.

BOM Item Mappings

BOM items don't have tags in their frontmatter, so we created an explicit artifact-mappings.yaml that assigns 2-3 topics to each of the 33 items. For example, "Orbital Tugs" maps to ion-propulsion, fleet-management, and propellant-systems.

What Changed in the UI

• New /topics page — Browse all 13 domains with artifact counts per topic
• New /topics/[topic] pages — See all linked artifacts grouped by type (questions, BOM items, blog posts, validations), plus sibling and related topics
• TopicPill component — Tags on QuestionCard now link to their topic page (mapped tags get cyan styling; unmapped tags stay dimmed)
• Header navigation — "Topics" link added between "Questions" and "Organizations"

Future Directions

The ontology is designed as a living taxonomy. Running node scripts/bootstrap-ontology.js --show-unmapped reports which tags still need mapping. As new content is added, simply add legacy tags to existing topics or create new ones — no content file changes needed.

Next steps may include:

• Topic-aware search and filtering on the questions page
• "Related Topics" sections on BOM item detail pages
• Topic-based RSS feeds for subscribers interested in specific domains