🛰️ Satellite Simulation with Basilisk

This project implements a satellite imaging simulation using the Basilisk framework. It features:

    orbital and rotational dynamics,

    a real-time control interface via ZMQ,

    live 3D visualization with Vizard,

    a configurable onboard camera pointing toward Earth (nadir).

🎯 Purpose

This script simulates a satellite in Earth orbit and allows real-time orientation control using external commands (via ZMQ). It integrates Basilisk’s modules for spacecraft dynamics, attitude, gravity, and visualization, making it useful for testing imaging concepts and satellite pointing mechanisms.
⚙️ Key Features

    Classical orbit initialization (COEs: altitude, inclination, etc.)

    Orientation using Modified Rodrigues Parameters (MRPs)

    Onboard camera with a wide field of view (120°)

    Real-time ZMQ interface to command spacecraft attitude (roll/pitch/yaw)

    Live visualization via Vizard

    Plots of orbital inclination and position over time

📦 Dependencies

    Basilisk

    numpy, matplotlib

    tkinter (for the stop button GUI)

    spiceypy

    pyzmq

    json

🛰️ Simulation Overview

    Basilisk Modules Used:

        Dynamics: spacecraft, extForceTorque, simpleNav

        Gravity: simIncludeGravBody, spiceInterface

        Attitude: attTrackingError, mrpFeedback

        Visualization: vizSupport, vizInterface, pinholeCamera

    Real-time control:

        Subscribes to ZMQ messages on port tcp://localhost:5559

        Accepts attitude commands formatted as:

        {
          "type": "attitude_command",
          "roll": 0,
          "pitch": 0,
          "yaw": 0
        }

🚀 How to Run
1. Run the script

python script.py

This will:

    Initialize the simulation with default orbit parameters

    Launch a ZMQ listener for attitude commands

    Open a Tkinter window with a red "Stop" button

    Stream simulation data live to Vizard

2. Default Orbit Parameters

initialCoordinate(1500., 10.7579, 59.9115, 65., False)

This corresponds to:

    Altitude: 1500 km

    Longitude: 10.76°

    Latitude: 59.91°

    True anomaly: 65°

    Southward orbit

You can change these values to simulate other orbits.
📷 Camera Configuration

    Points initially in the -Z direction (nadir)

    FOV: 120°

    Controlled by the spacecraft’s body frame

    Adjusts dynamically via attitude commands

🖥️ Stop Simulation GUI

A simple Tkinter window appears with a “Stop” button to safely terminate the simulation.
📊 Output

Two key plots are generated:

    Inertial Position of the spacecraft over time (in km)

    Inclination evolution over time vs. initial inclination

Plots appear at the end of the simulation if show_plots=True.
📂 Files

    simulationTools.py: Auxiliary math and orbital functions (required)

    orientation.py: Includes process_command() for attitude handling (required)

    LiveScenario.viz: Vizard visualization file name

✅ Notes

    The simulation runs one orbit period per loop iteration.

    Real-time orientation control is handled via a ZMQ subscriber.

    Basilisk uses SPICE data for precise ephemeris initialization.

    The satellite's orientation is initialized to point toward Earth (nadir).

    Orientation is internally represented using MRP (Modified Rodrigues Parameters).