FS · SITE 001

Open-source software for hobby and high-power rockets.

FusionSpace makes free software for rocketry: HPR Sim, a flight simulator, and the suite being built around it.

Start with HPR Sim Source on GitHub
SHEET 1 / 4

FusionSpace HPR

One suite for hobby and high-power rockets, written in Rust: a flight simulator first, then a flight analyzer, a competition kit and an app. Every product's source and releases live in one repository, nrdptel/fusionspace-eridanus, under the MIT or Apache-2.0 license.

HPR Sim is the one released so far. Before you rely on a number from it, read how far to trust a simulation: what it was checked against, and where it hasn't been.

Each product is numbered like a part on a drawing once it ships. Released means published and maintained; in preparation means not published yet.
ProductStatusGuide, docs and release
FS-ACHERNAR · SW · TOOL 001
FusionSpace HPR · Sim
A flight simulator for hobby and high-power rockets: a Rust library, the hpr command and a Python package.
 Released
0.1.0 · 2026-10-08
Numbered when it ships
FusionSpace HPR · Analyzer
Reads a flight computer's log and sets the flight beside its simulation.
 In preparation
Planned for release 0.2
 None yet
Numbered when it ships
FusionSpace HPR · Competition Kit
Challenge rules, presets and submission packs for student rocketry competitions.
 In preparation
Planned for release 0.4
 None yet
Numbered when it ships
FusionSpace HPR (the app)
Design, simulation and flight replay on the desktop, the web and phones.
 In preparation
A preview in release 0.5, then 1.0
 None yet
Numbered when it ships
FusionSpace HPR · Motor Designer
Design of experimental solid motors.
 In preparation
After release 1.0
 None yet
Numbered when it ships
FusionSpace HPR · Recovery Designer
Parachute gores and opening loads.
 In preparation
After release 1.0
 None yet
Numbered when it ships
FusionSpace HPR · Avionics
Flight computer logic and a ground station.
 In preparation
After release 1.0
 None yet
SHEET 2 / 4

Other projects

The brand system every FusionSpace tool follows, with its two tools, and the two projects FusionSpace HPR replaces.

Withdrawn means no longer maintained; the tool stays online for now.
ProjectStatusWhere
FS-ARA
FusionSpace brand system
The name, the mark and the product rules: how every FusionSpace site, tool and app is designed.
 Released
Rev C
 nrdptel/fusionspace-design
FS-CERVANTES · SW · TOOL 001
Callsign
The star-name tool: each project takes a constellation, each product one of its stars.
 Released In the brand system
FS-INQUILL · SW · TOOL 001
Mark Tuner
Tunes the mark and both lockups in the browser and exports them as SVG.
 Released In the brand system
Not numbered
Loft
A flight simulator for the browser that read OpenRocket designs. Replaced by FusionSpace HPR · Sim: from the command line and Python now, in the browser with the app.
 Withdrawn
Not numbered
Debrief
A flight-log analyzer for the browser. FusionSpace HPR · Analyzer is to replace it, in release 0.2.
 Withdrawn
SHEET 3 / 4

Web tools

Four tools for the browser that came before FusionSpace HPR. Each will be rebuilt inside it; until its rebuild ships, the tool keeps working at its own address.

All four are released and maintained.
ToolStatusWhere
FS · SW · TOOL 001
HPR Motor Finder
AeroTech, Cesaroni and Loki motor stock and prices across U.S. vendors, matched to ThrustCurve.
 Released motor.fusionspace.co
FS · SW · TOOL 002
Charge
Sizes black-powder ejection charges, every constant shown, with a log of your ground tests. Ground test every charge first.
 Released charge.fusionspace.co
FS · SW · TOOL 003
Window
Launch weather for high-power rocketry at any U.S. field: surface wind, winds aloft, storms, cloud ceiling and a few days ahead.
 Released window.fusionspace.co
FS · SW · TOOL 004
Muster
Which reloads, closures and spacers fit each reloadable motor case, and the parts to buy.
 Released muster.fusionspace.co
SHEET 4 / 4

Principles

The rules every FusionSpace tool is designed to. HPR Sim's docs give each model's equations, its sources and what it was validated against.

Show the working

Formulas, constants and sources are there to read, not hidden.

Say how far to trust it

Estimates are labeled as estimates, with their spread. Never a go/no-go verdict.

Work at the field

Readable in sun, with big targets for cold hands. HPR Sim's core needs no network.

No accounts, no tracking

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