FS · SITE 001

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

I make free software for rocketry under the name FusionSpace: HPR Sim, a flight simulator, and the suite I'm building around it.

Start with HPR Sim Source on GitHub
SHEET 1 / 4

FusionSpace HPR

It's one suite for hobby and high-power rockets, written in Rust. The flight simulator comes 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.

Only HPR Sim is 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.

Once a product ships, it gets a number, like a part on a drawing. Released means it's published and maintained. In preparation means it isn't 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

Every FusionSpace tool follows one brand system, and the system has two tools of its own.

All three are released and maintained.
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
SHEET 3 / 4

Web tools

These four browser tools came before FusionSpace HPR. I'll rebuild each one inside it, and 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

I design every FusionSpace tool to these rules. 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

An estimate says it's an estimate and shows its spread. You never get 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

This site sets no cookies and loads nothing from anyone else. It keeps one thing, your theme choice, in your own browser.