Asteroid Mining
Project Overview
The main objective of this project is to formulate a cycler orbit between Earth and a Trojan asteroid in the asteroid belt in the Sun-Earth-Jupiter dynamic system. The cycler orbit will be defined using Lamberts Equations. Once the orbit is defined rendezvous trajectories between Earth and Hektor will be developed.
Current Status
After research done in the previous semester STK did not have the tools necessary to allow us to plot our desired orbit so we moved to Matlab. In Matlab we are using Lambert’s equations to develop the orbit. Our plan is to then import the chosen orbit from Matlab into STK for further analysis of the space environment and engineering requirements.
The Matlab script is set up to take in the initial and final position of the satellite and then develop all appropriate lambert solutions. The next step is to take the results of those solutions and plot them to compare.
Next Steps
The next step after the orbit is defined in Matlab is to import the orbit into STK for analysis of the delta v requirements, the space environment it is traveling through, and its link budget. If possible, the plan is to model some of the major effects of other asteroids around L4.
Satellite Tracking
Project Overview
The objective of this project is to analyze the impact of the Sun’s radiation pressure and its solar activity cycles on the orbital precession of satellites, using real telemetry data to quantify deviations in orbital elements. This study aims to compare theoretical predictions with observed behaviors to improve the understanding of solar-induced perturbations and their implications for satellite operations and orbital design.
Current Status
Members are using SatNOGS to access information about satellites to predict overpasses, investigate telemetry, and assess orbits.
So far, the VZLUSAT-2, Unicorn-1, NOAA 15, StratoSat-TK1, and Bluebird 03 satellites have been looked at.
Next Steps
Start investigating what factors are contributing to the decay of each satellite which has been looked at and see how much the Sun’s is affecting it.
Optimal Control Contract - PSP AC
Project Overview
PSP Active Controls (AC) is developing a liquid rocket engine powered lander, and wants to use optimal control for their Astra lander either through model predictive control (MPC) or by generating reference trajectories for a PID controller. ASA will use our knowledge in this area to help them learn the basics and create tools to demonstrate the feasibility and eventually implement this control technique.
Current Status
First, we used the Sequential Convex Programming Toolbox in Julia to familiarize ourselves with applying convex programming powered optimal control techniques to a rocket powered landing scenario. We started with a simple planar landing model and built up to a full six degree of freedom landing model of PSP AC’s Astra lander.
To begin testing controller performance in Matlab, we started off developing a baseline solver in MATLAB with CasADi. This first version included a basic cost function to minimize thrust effort and angular velocity. With initial conditions of starting 1000 meters above the ground falling at 80 m/s, it converges. The results are shown below:
Further iterations included adding thrust and gimbal rate limit constraints so the model wouldn’t try extremely rapid maneuvers.
Currently, we are working on several things:
- Writing a 6DoF model with quaternions rather than Euler angles.
- Integrating CasADi with the 5DoF and 6DoF models in Matlab Simulink
- Working on testing disturbance modeling and mismodeling of vehicle properties to see how they affect controller performance.
Next Steps
Once the Simulink model with 6DoF is completed in CasADi and robustly tested, we will move on to using Sequential Convex Programming in Matlab to create our own controller as well as testing other real time capable algorithms. Also, we will continue to make more accurate models such as a model that includes the change in mass from propellent being burned.
6DoF Rocket Simulator - PSP HA
Project Overview
A rocket trajectory simulator that can be used as a sizing and design tool as well as for high fidelity analysis of the rocket’s trajectory and performance. This project is with PSP High Altitude and they want to use it to help them design their eventual space-shot rocket.
Current Status
We have developed the 6DoF rocket simulator model in Matlab Simulink and are using the Air Force’s DATCOM model for computing the aerodynamics. Our main work right now is to validate the model with past flight data and also to use it to test the avionics team on High Altitude’s custom flight computer.
Next Steps
In the future we would like to revist using this simulator for the optimization of the rocket geometry and validate its performance using computational fluid dynamics models. Also, there is a possibility we can turn our work on this into a conference paper.
