The primary goal of this STTR Phase II project is predictive modeling of E-sail spacecraft thruster performance using a high-fidelity computational approach. We plan to develop parallel 3D Particle-In-Cell (PIC) codes with improved boundary conditions to simulate interactions between the solar wind plasma and E-sail, which will be validated against thrust-stand measurements of a laboratory prototype. The work will provide NASA researchers with a knowledge base for designing, testing, and optimizing the E-sail propulsion system, and further assist in navigation and control. The proposed PIC simulations will significantly improve the state-of-the-art theoretical and computational analyses of E-sails that are highlighted in our Phase I effort. The self-consistent 2D/3D PIC approach will address a number of outstanding physical and numerical issues, such as spacecraft charging, electron gun operation, and free stream boundary conditions, ultimately leading to the development of a reduced-order model for the full-scale in-space operation. Two codes will be used to allow for verification and benchmarking of the simulation tools: Stanford University's SPIC plasma code and AFRL's SM/MURF multi-physics code. The proposed code development also offers an opportunity for technology transfer from RI to SBC and from SBC to NASA. The companion experimental work will supply extensive thrust measurements under controlled and well characterized laboratory conditions, and thus enable extensive validation of PIC models and algorithms. Upon success of the Phase II effort, we envision that the validated PIC-based approaches will be well suited to examine key issues of E-sail spacecraft controllability and optimization, including its size and layout, as well as adapting it to the changing plasma environment for in-space operations.
Astrophysics: problems involving kinetic effects with complex nonlinear interactions between electromagnetic fields and background plasma, such as cosmic rays.
Spacecraft propulsion: electric and plasma thrusters.
Spacecraft performance: plasma interactions, spacecraft charging, attitude control.
Satellite problems: contamination assessment and electric arc
Industry: space industry; plasma-controlled nano- and micro-fabrication technologies such as dry etching in lithography, low temperature direct bonding, and plasma-enhanced chemical vapor deposition; plasma-assisted mass spectrometry.