Advancing CubeSat Propulsion:Investigating & Optimizing Onboard Propulsive Units

The Problem 🚀:

The project, "Design and Simulation of an Articulated On-board CubeSat Propulsion System," was driven by the need to address issues related to CubeSat missions. CubeSats are miniature satellites used in scientific research, but they often face challenges like orbit decay and difficulty in reaching their designated orbits. The motivation behind this project was to develop an onboard propulsion system to enhance the functionality and mission life of CubeSats, ultimately optimizing their effectiveness in scientific research and space exploration.

The Solution/Approach:

This project proposed an innovative solution: an articulated CubeSat propulsion system with two stages.

• The first stage utilized an onboard laser system to create laser-sustained plasma, providing initial propulsion until the propellant was depleted.

• The second stage featured gridded ion thrusters (GIT), optimizing mission life. High impulse and long endurance were the primary objectives.

To validate the system's performance and address the absence of practical experimental setups, the project employed CFD simulations using Ansys Fluent along with the MHD (Magneto-Hydrodynamics) module. The simulations aimed to evaluate temperature, pressure, and velocity conditions. The research intended to visualize the flow characteristics, ultimately contributing to space exploration through computational fluid dynamics.

The Outcome - Two is better than One!!

This research was conducted in two parts for a better understanding of the underlying scientific concepts as listed below:

1. Design and Simulation of an Articulated On-board CubeSat Propulsion System
   [Published & Presented at the AIAA Propulsion & Energy Forum 2020]

   • The project used a combination of 2D and 3D simulations to investigate the effectiveness of two different hollow Cathode Ray Tube (CRT) geometries for the onboard GIT unit. By varying mass flow rates and studying different input parameters such as velocity, temperature, pressure, and turbulent kinetic energy, the research aimed to optimize the system's design most efficient design and operating conditions.

     

   • Based on the theoretical research and MHD simulations conducted in this project, a viable Low Current - Moderate Voltage operating configuration is proposed that has been found to increase the ion velocity in the cathode plume region of the Gridded Ion Thrusters’ Cathode models, thereby increasing the chance of greater exhaust velocities under ideal conditions.

   • based on the multiple input conditions that were computationally tested, the type B orifice design always yields better results when compared to type C. Thus, the design and simulation of a gridded ion thruster was performed successfully and the feasibility has been validated under ideal conditions.

2. Magneto-Hydrodynamics Simulation of an Articulated On-Board CubeSat Propulsion System
   [Published & Presented at the IAC 2020 - Space Propulsion Symposium]

   • Methodology:

     • The main objective of this paper is to carry out the 3D simulations using the best-fitted geometry and boundary conditions to establish a comparison between 2D and 3D simulations. A variation of mass flow rates with the imposition of the same other conditions enabled us to study the different parameters whilst optimizing the temperature.

       

   • Inferences:

     • The research project concluded that 3D simulations of the gridded ion thruster's plasma generator region yielded more accurate and realistic results compared to 2D simulations. It was observed that the 3D simulations allowed for a better understanding of the impact of multi-planar dynamics on the flow field, resulting in improved performance.

     • The project found that variations in mass flow rates had a significant impact on velocity, temperature, and turbulent kinetic energy, and identified optimal conditions for the propulsion system.

How are these projects unique?

These two projects are uniquely correlated as they both aim to enhance space technology in different ways. The "Articulated On-board CubeSat Propulsion System" project introduces an innovative solution for CubeSat missions, while the "Low Current - Moderate Voltage Gridded Ion Thruster" project explores advanced ion thruster configurations. Both projects share a common theme of enhancing advanced space propulsion systems. The novelty lies in their innovative approaches and the application of advanced CFd, MHD & sophisticated simulations, contributing to multifaceted applications in space exploration and satellite technology.