Hesper Titan Atmosphere Sounder

Titan has thick weather: nitrogen skies, methane drizzle and seasonal storms that can drop visibility to a few hundred metres. Hesper orbits at 1,400 km above the haze and uses infrared sounders to profile temperature, humidity and opacity from the surface to 600 km altitude. It produces a 72-hour forecast every six hours.

Those forecasts are the reason Cascade Dropship crews can schedule landings on Titan with the same confidence they have on Mars. They also feed the habitat siting work for the Meridian Colony Ark programme, which plans to put its first 4,800 settlers on the shores of Kraken Mare.

Forecast grids and lake maps are available under CC-BY-4.0. Outer-system operators and academic atmospheric groups use the archive to train their own regional models, and several have contributed improved radiative transfer code back to the project.

If you work on planetary meteorology, the most useful contribution right now is verification: comparing Hesper forecasts with ground station observations collected by settlement survey teams. Current products include methane weather forecasts, haze opacity profiles and surface lake maps. Everything is distributed under the CC-BY-4.0 licence, with source and documentation at https://git.halcyon.example/hesper-titan, and the open data team answers questions on the community forum within two working days. Partners who build commercial services on top of it are asked only to credit Halcyon Stellar Works and to report errors they find, so that every user benefits from the fix.