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GP-AE-0EMGW7RAerospaceReady

Basilisk Reaction-Wheel Desaturation Study

A spacecraft dynamics and controls study of reaction-wheel momentum build-up and magnetic-torquer desaturation across actuator, orbit, disturbance, gain, and sensor-noise cases.

Basilisk Reaction-Wheel Desaturation Study project visual
GP-AE-0EMGW7R · Aerospace
  • Python 3.12
  • Basilisk 2.11.1
  • NumPy
  • SciPy
  • pandas
  • Matplotlib

Project definition

Problem statement

Reaction wheels reject external disturbance torque during attitude control, but the stored wheel momentum can continue to increase until actuator speed limits are approached.

The engineering problem is to remove wheel momentum with magnetic torque rods while preserving attitude control, and to measure how actuator authority, orbit geometry, disturbance, control gain, and measurement noise affect the result.

Project objectives

  • Build a six-degree-of-freedom spacecraft simulation with a four-wheel pyramid and three magnetic torque rods.
  • Implement inertial attitude control and a magnetic momentum-unloading law.
  • Compare dipole authority, unloading gain, inclination, disturbance torque, and magnetometer noise across 18 cases.
  • Measure wheel momentum, wheel speed, attitude error, control effort, and torque-rod saturation.
  • Verify magnetic torque reconstruction and reaction-wheel speed integration independently.

Project structure

Project components

01

Spacecraft model

Defines rigid-body mass properties, orbit, four reaction wheels, three torque rods, and the disturbance torque.

02

Attitude controller

Calculates the wheel torque required to maintain the commanded inertial attitude.

03

Momentum unloading

Commands magnetic dipole from wheel momentum and the simulated geomagnetic field.

04

Basilisk scenario

Connects dynamics, environment, navigation, control, actuators, messages, logging, and the simulation schedule.

05

Campaign runner

Executes the 18 prepared cases and retains consistent engineering measures and time histories.

06

Verification pipeline

Checks equations, configurations, retained results, torque reconstruction, wheel integration, tests, documents, and the container workflow.

Methodology

Project workflow

  1. 01
    Load the spacecraft

    Read the released mass, inertia, orbit, wheel, torque-rod, controller, disturbance, and campaign settings.

  2. 02
    Run the coupled simulation

    Basilisk advances the orbit, attitude, reaction wheels, magnetic field, controller, and unloading law.

  3. 03
    Retain the evidence

    Each case records wheel states, momentum, attitude error, magnetic field, dipole command, and applied torque.

  4. 04
    Compare the cases

    The analysis measures momentum reduction, wheel-speed margin, pointing response, control effort, and actuator saturation.

  5. 05
    Check the calculation

    Independent high-rate calculations reconstruct magnetic torque and integrate wheel acceleration from applied torque.

Demonstration scenario

The nominal case reduces reaction-wheel cluster momentum from 0.0204124 to 0.0132149 N m s, a 35.26 percent reduction, while retaining 28.02 percent wheel-speed margin. The torque-rod saturation duty is 99.06 percent, identifying magnetic authority as the principal constraint in the released case.

Engineering

Tools and method

Tools
The project uses Python 3.12, Basilisk 2.11.1, NumPy, SciPy, pandas, Matplotlib for subject analysis, simulation, and results.
Dynamics and control
Basilisk 2.11.1 models rigid-body motion, reaction-wheel dynamics, orbital motion, magnetic torque, and message-based flight software.
Campaign
Eighteen controlled cases vary one principal actuator, environment, disturbance, control, or noise condition at a time.
Analysis
Python, NumPy, SciPy, pandas, and Matplotlib produce full-precision tables, summaries, and figures from the retained histories.
Verification
Independent closure checks, 51 tests, 99.43 percent branch-aware coverage, dependency checks, repository validation, and a digest-pinned Linux container run support the release.

Testing

Evaluation

Evaluation measures

  • Reaction-wheel cluster momentum reduction
  • Peak wheel speed and remaining speed margin
  • Attitude error and body-rate response
  • Magnetic dipole command and saturation duty
  • Magnetic-torque reconstruction error
  • Reaction-wheel integration error

Project boundaries

  • The geomagnetic environment uses a centered-dipole Earth model rather than IGRF or WMM.
  • The body disturbance is constant and does not represent a measured mission torque spectrum.
  • Navigation is truth-based, and the magnetic noise model omits bias, scale factor, self-field, and calibration effects.
  • Reaction wheels and torque rods use idealized actuator behaviour.
  • The spacecraft is rigid and omits flexible modes, power, thermal behaviour, hardware testing, and flight validation.

Included

  1. 01Complete Python and Basilisk source code
  2. 02Released 18-case spacecraft simulation campaign
  3. 0315,336 retained time-history rows in CSV and JSON formats
  4. 04Twelve labelled engineering figures and diagrams
  5. 0571-page project report in PDF and editable Word formats
  6. 0617-page setup and usage guide in PDF and editable Word formats
  7. 0754 annotated references and two attributed NASA literature images
  8. 0851 automated tests with 99.43 percent branch-aware coverage

Project record

No information is collected on this page.

Permanent project ID
GP-AE-0EMGW7R
Catalogued
21 Aug 2026
Completed
28 Aug 2026
Verified
28 Aug 2026
Demonstration
Included in repository

Handover

After purchase

  1. 01
    Payment is confirmed

    The project is marked unavailable and cannot be purchased again.

  2. 02
    Repository access is granted

    The buyer's submitted GitHub account receives access to the private repository.

  3. 03
    The purchase record is delivered

    The certification sheet is prepared from the reviewed buyer details and sent privately by email.