Flipper Space Calculators

March 23, 2026 ยท View on GitHub

A pair of minimalist space and physics calculators for the Flipper Zero. No games, no splash screens -- just the numbers.

Applications

Space Travel Calculator

Interplanetary trajectory planner with real-time orbital visualization. Select a destination (Mars, Venus, Jupiter, Europa, Titan, and more), scroll through launch dates, and see Hohmann transfer orbits drawn on screen. Outputs delta-v requirements, flight time, and phase angles.

Dilate

Time dilation calculator for special relativity. Set a velocity (fraction of c) and a duration, and see how much time passes for you versus an observer on Earth. Auto-scales units from seconds to years.

Installation

Pre-built .fap files (easiest)

  1. Download space_travel_calculator.fap and/or dilate.fap from the latest release.
  2. Connect your Flipper Zero via qFlipper or mount the SD card directly.
  3. Copy the .fap files to SD Card/apps/Tools/ on the Flipper.
  4. On the Flipper, open Apps > Tools and select the calculator you want.

Firmware compatibility

The pre-built .fap files in releases are compiled for Momentum firmware mntm-009 (API 79.2). If you are running a different firmware or API version, you will need to build from source (see below).

Building from Source

The recommended way to build Flipper Zero apps is with ufbt (micro Flipper Build Tool).

1. Install ufbt

pip install ufbt

2. Set up the SDK

For Momentum firmware (recommended if you use Momentum):

ufbt update --index-url=https://up.momentum-fw.dev/firmware/directory.json

For stock Flipper firmware:

ufbt update

3. Clone and build

git clone https://github.com/ejfox/flipper-space-calculators.git
cd flipper-space-calculators

Each app is built separately from its own directory:

# Space Travel Calculator
cd space-travel-calculator
ufbt
cd ..

# Dilate
cd dilate
ufbt
cd ..

Compiled .fap files will be in each app's dist/ directory.

4. Deploy directly to Flipper (optional)

From inside either app directory:

ufbt launch

Testing

Both calculators include unit tests for their core calculation functions, run via GitHub Actions on every push and PR.

  • Space Travel Calculator: 14 tests (orbital mechanics, Hohmann transfers)
  • Dilate: 15 tests (Lorentz factor, time dilation)

Run tests locally from each app's directory:

cd space-travel-calculator && make -C tests && cd ..
cd dilate && make -C tests && cd ..

Project Structure

flipper-space-calculators/
  space-travel-calculator/    # Orbital transfer calculator
    application.fam
    calculations.h/c          # Core physics functions
    tests/                    # Unit tests
    ...
  dilate/                     # Time dilation calculator
    application.fam
    calculations.h/c          # Core physics functions
    tests/                    # Unit tests
    ...
  .github/workflows/          # CI test runner

License

MIT where applicable. See individual app directories.