Overview
The Smart Nano-satellite Attitude Propagator (SNAP) is a 6-DOF satellite attitude propagator implemented in MATLAB and Simulink that can be used to analyze the environmental torques affecting a satellite and to design and analyze passive attitude stabilization techniques, such as Passive Magnetic Stabilization and Gravity Gradient Stabilziation.
The model implements:
- A simple two-body gravitational model for orbit propagation
- Gravity gradient torque
- Magnetic torque due to permanent magnets
- Magnetic Hysteresis torque and damping
Applications
SNAP can be used to simulate the attitude and pointing dynamics in orbit for passive satellites. This is suitable for light-weight satellites (CubeSats, Nano-satellites, etc) whose attitude stability is largely affected by external environmental torques that are normally ignored in larger spacecraft design. SNAP was initially designed to simulate magnetic field tracking stabilization using permanent-magnets and hysteresis material for damping. It can also be used to simulate earth-pointing stabilization using a gravity gradient bias.
SNAP in its current state does not incorporate any active control schemes yet (reaction wheels, torque rods, momentum wheels, etc).
Example
The following video is a simulation of KySat-1. It is passive magnetically stabilized using a set of permanent magnets and hysteresis strips. SNAP simulates the attitude and produced an STK (Satellite Tool Kit by AGI) attitude file. The animation is done in STK, SNAP only produces the plots and is capable of outputting the attitude history.
Video of Simulated KySat-1 in Orbit
References
For more information on the implementation and capabilities of the model, see:
- [1] Samir Rawashdeh, “Passive Attitude Stabilization for Small Satellites”, Master’s Thesis, University of Kentucky 2010, Lexington, KY (download)
- [2] Samir Rawashdeh, James Lumpp, “Nano-Satellite Passive Attitude Stabilization Systems Design by Orbital Environment Modeling and Simulation”, AIAA Infotech@Aerospace Conference 2010, Atlanta, GA
More Information
Release Notes, Frequently Asked Questions
Download
Please consult the Release Notes and FAQ above for information on running SNAP and the Minimum Requirements.
Minimum Requirements:
- MATLAB 2009a or newer.
- 32-bit Windows XP or newer.
- Please read Release Notes for more detailed requirements.
