About
What is this?
cyclers.space is an open catalogue of planetary cycler trajectories: repeating heliocentric orbits that periodically encounter two or more planets without propulsive maneuvers (or with only small course-correction burns). They were proposed in the 1980s by Aldrin and Niehoff as the backbone of a sustainable Earth-Mars transport architecture, and the literature on them is now scattered across four decades of papers, dissertations, and conference proceedings.
There is no single canonical public database. This site exists to be one — generated from a YAML file under version control, with every numerical value traceable to a specific table or page in the cited source.
Validation levels (V0–V5)
Each entry carries a validation level, drawn from the design spec of the upstream cyclers project. Currently every entry is V0 — literature-sourced but not independently re-derived by this project. Higher levels are populated as the upstream finder and validation gauntlet produce them.
| Level | Meaning |
|---|---|
| V0 | Literature: a cycler reported in a published source. Not independently re-derived. |
| V1 | Reproduced in a circular-coplanar model; signature matches the literature within binning tolerance. |
| V2 | Reproduced in a real ephemeris model; closes the loop for at least one full cycle within drift tolerance. |
| V3 | Holds over a multi-cycle horizon with bounded TCM ΔV budget. |
| V4 | Cross-validated in an independent astrodynamics tool (e.g. GMAT). |
| V5 | Published, peer-reviewed re-validation. |
Attribution policy
For every entry, attribution goes to the earliest published source. Later
elaborations, corroborations, or re-tabulations are listed as
corroborating sources. If this project's finder later re-derives a literature
cycler, the entry is tagged as a known-reproduction; the original authors
keep the credit. This rule mirrors spec §16.4.
If you find an attribution error, please open an issue on the site repo.
How to contribute corrections
The catalogue is a single YAML file:
src/data/seed_cyclers.yaml in the
cyclers.space repo. Open a pull
request with the change, including the verbatim quote and source identifier (page,
table, equation number, DOI) for every modified numerical value. Bare numbers without
provenance are not accepted.
Data flow
The site is a static build of the YAML catalogue. v1 copies the YAML in at bootstrap time; the long-term plan is for the build to pull the latest version from the upstream cyclers repo on a schedule. The site has no backend, no analytics, and no JavaScript beyond the small client-side island that powers the planet filter and column sorting on the catalogue page.