AUDACIA ASTRA

An interstellar mission planner built on real astrometric data and real physics.

AUDACIA ET PERSEVERANTIA · ASTRA REVELANT

What it is

Audacia Astra is a simulator, not a space opera. Every star in its 200 light-year bubble comes from the HYG astrometric catalog, every one of them is moving, and every mission you plan has to deal with that.

Intercept solving — ships meet stars where they will be on arrival, not where they appear tonight. The solver reports positional uncertainty at the destination.
Real relativity — exact time dilation, ramp/cruise/decel flight profiles at a crew-tolerable g-load, kinetic-energy budgets that will humble you. An optional FTL mode exists and is labeled as the fiction it is.
Multi-star routes — waypoint chains where each leg departs when the previous one arrives. Route optimization is a moving-target traveling-salesman problem, solved honestly.
The interstellar medium — local gas clouds erode shielding at relativistic speed; routes are assessed against real region models.
Pulsar navigation — checkpoint fixes chosen by geometry from millisecond pulsars in the ATNF catalogue.
Mission dossiers — export any plan as a printable PDF: flight-profile charts, thrust and power figures, intercept geometry, navigation checkpoints.

Where the simulation simplifies, it says so on the label. That is the house rule.

Screenshots

The solar neighborhood against the Milky Way band — Sol centered with Alpha Centauri, Sirius, and Ross 614 labeled, mission planning panel on the right — The solar neighborhood. Every point is a real star from the catalog; the panel on the right is a mission being planned.

Intercept marker on Achird at one light-year out, seen against the galactic plane edge-on — One light-year from Achird — the intercept marker sits where the star *will be*, not where it appears.

61 Cygni B at one astronomical unit, the galactic band stretching behind it — Arrival: 61 Cygni B at 1 AU.

Download

Early access 0.1.3 — free while the simulator matures.

macOS0.1.3 on itch.io · Apple Silicon Windows0.1.0 on itch.io · x64

Prefer no middleman? Direct downloads — macOS (403 MB), SHA-256: a7d000bb32bbd88ff77045d07374445b1f11d0382de7321c0fecc2a295c4f41e · Windows (355 MB), SHA-256: 271d812f76f11b313272ee2517c4c52f851e7288c3d537481bee1a68506b3d96. The itch.io archives are repackaged by itch and hash differently; itch verifies its own downloads.

Builds will be posted here with SHA-256 checksums. During early access the binaries are unsigned — a solo project has not yet bought code-signing certificates — so your system will warn before running them:

Windows: SmartScreen shows “Windows protected your PC.” Click More info → Run anyway. Some antivirus may flag the unsigned executable; this is a false positive common to indie Unreal Engine builds — verify the checksum against the value listed here if you want certainty.
macOS: Gatekeeper blocks the first launch. Right-click the app → Open, then confirm.

Signed, notarized builds are on the roadmap once the project can justify the certificate cost.

Follow along

Development happens in the open — devlogs on the physics, the design decisions, and the honest simplifications: devlog on itch.io.

Contact: support@audaciaastra.com

Data & attribution

Star catalog: HYG Database v4.1 — David Nash, astronexus.com (CC BY-SA).
Pulsars: ATNF Pulsar Catalogue v2.6.4 — Manchester et al. (2005).
Interstellar-medium region parameters from published literature.
Built with Unreal Engine.