We propose a laser induced fluorescence heterodyne approach to resolve the timedependent ion velocity distribution (IVDF) in a Hall thruster. This approach is motivated by studies of low frequency modes of oscillations in Hall thruster, including azimuthal or so-called spoke and axial or so-called breathing oscillations. In this paper, we present the first successful application of this method ...

The current interest in ion thrusters for near-Earth and deep-space missions has occurred because of long-term development efforts yielding an understanding of the physical phenomena involved in thruster operation and hardware that is suited to a wide range of missions. Features of state-of-the-art thrusters are described in terms of the various physical processes that occur within them. Tradeo...

We develop tracking control laws for a rigid spacecraft using both thrusters and momentum wheels. The model studied comprises a rigid body with external thrusters and with N rigid axisymmetric wheels controlled by axial torques. The thruster torques and the axial motor torques are the controls used to track given attitude motions. Specifically, the thruster torques are used to implement the coa...

It is well known that each thruster on the SPHERE produces slightly different thrust and behaves differently (see [Chen] and [Berkovitz]). Some methods were developed by [Chen] to compensate for the difference in thrust between thrusters and improve the open-loop performance of the SPHERE, but they were yet to be demonstrated. An experiment was performed onboard NASA’s KC-135, during microgravi...

A MATLAB-based software tool, called the Solar Sail Control Toolbox, has been developed for solar sail analysis, design and simulation. The toolbox includes functions for multibody dynamic modeling, attitude control systems design, thrust vector control design, orbit analysis, solar sail mission analysis, thermal analysis and power subsystem analysis. Sailcraft models can be created, analyzed a...

This article developed an ion thruster optic system sputter erosion depth numerical 3D model by IFE-PIC (Immersed Finite Element-Particle-in-Cell) and Mont Carlo method, and calculated the downstream surface sputter erosion rate of accelerator grid; compared with LIPS-200 life test data. The results of the numerical model are in reasonable agreement with the measured data. Finally, we predicted...

In this paper, an adaptive control technique is applied to controlling the chaotic behavior in thruster motor system for deepwater ocean robot. This chaotic oscillation has a direct impact on the stability, reliability and security of the robot. In addition, the proposed approach is also verified in the way of both flexibility and effectiveness, and a kind of chaotic controller that is applicab...

The azimuth thruster is mainly installed on a vessel that requires dynamic positioning (DP) function for special purposes. When the operates DP, thrust loss induced by thruster-hull interaction. This study examined influence of boundary conditions in numerical simulations predicting loss. Wind turbine installation vessels (WTIV) and floating production storage offloading (FPSO) were chosen as t...