Planetary Guidance
System/Tracker

Nighttime backyard scene with a telescope pointed upward, a bright moon in the sky, stars, a wooden fence surrounding the yard, and garden lights illuminating the plants.

Navigating the stars isn’t just for sci-fi, this Arduino-based star tracker brings celestial positioning to life. Using gyros, stepper motors, an RTC module, and custom 3D prints, this system locks onto stars for precise tracking.

Beyond the build, detailed documentation covers everything from the basics of positional astronomy to design schematics, troubleshooting tips, and a full code repository. Whether mapping constellations or refining guidance systems, this project bridges engineering and the cosmos, one calculated step at a time.

A robot with a white gear-shaped body, connected to an Arduino Uno and other electronic components with various wires, on a cluttered desk with tools and tape.
A celestial diagram showing the observer's meridian, star's apparent motion, celestial equator, and celestial horizon on a sphere marked with various lines and points.
A small robotic device with gears and wires, resembling a robotic telescope, set outdoors against a background of a fence and greenery.

Design & Components

The system consists of the following key elements:
1. Arduino Microcontroller: Serves as the processing hub, executing tracking algorithms and controlling motor movements.
2. Gyroscopes & IMUs: Measure orientation and angular velocity to refine positioning.
3. Stepper Motors: Enable precise movement of the tracker to follow a star’s apparent motion across the sky.
4. Real-Time Clock (RTC) Module: Provides accurate timestamps for celestial calculations.
5. 3D-Printed Enclosure & Mounts: Custom-designed for stability and optimized sensor alignment.

Functionality

  • Initialization & Calibration: The system reads initial orientation data from the gyroscopes and synchronizes time with the RTC module.

  • Positional Astronomy Calculations: Using known celestial coordinates and time data, the system calculates the expected position of a target star.

  • Motor Control & Tracking: The stepper motors adjust the tracker’s orientation to align with the target, continuously adjusting to compensate for Earth’s rotation.

  • Error Correction: Feedback from the gyroscopes ensures precise tracking, with real-time adjustments to minimize drift.

Applications & Potential

This project demonstrates the feasibility of low-cost, DIY star trackers. Potential applications include:
- Astronomy & Astrophotography: Enhancing long-exposure shots by compensating for celestial motion.
- Satellite & CubeSat Navigation: Providing an entry-level approach to star-based guidance systems.
- STEM Education & Research: Introducing students to positional astronomy and control systems.