This paper describes the design and testing of a miniature, 3D-printed cold gas attitude control thruster for the NASA Ames Research Center BioSentinel mission, an interplanetary small spacecraft that will be launched on the EM-1 flight of SLS. Earth-orbiting small satellites typically use magnetic torque rods for momentum unloading, but these cannot be employed in interplanetary space due to t...

* Presented as Paper IEPC-01-23 at the 27 International Electric Propulsion Conference, Pasadena, CA, 15-19 October, 2001. † Copyright © 2001 by the Electric Rocket Propulsion Society. All rights reserved. We present results from a numerical investigation of using a section of channel insulator with lower secondary electron emission coefficient to increase thrust and efficiency or reduce insula...

Understanding the behaviour of the magnetized plasma in the thruster ionization chamber is crucial to optimize the design and operation of this kind of thrusters. In particular, in Onera ECR thruster, the walls of the chamber can be dielectric, grounded or floating conductors. Depending on the boundary conditions, swirl currents may appear in the plasma; their effects on the plasma behaviour an...

The composition characteristics and working principle of the hydraulic rotary system azimuth thruster were analyzed. mathematical model dynamic pump-controlled motor driving gear reduction mechanism was established. Additionally, a fast tracking method for angle proposed to analyze angle, angular velocity response different desired angles. simulation results show that established can simulate m...

This paper describes the design and implementation of near-minimum-time control laws for the Advance Space Structures Technology Research Experiments test article located at the Phillips Laboratory, Edwards Air Force Base. The test article is equipped with compressed air thrusters that can be throttled. The mathematical model of the rotational motion is obtained by using experimental data and i...

Recent technological advances in the development of electric microthrusters pave the way to the successful diffusion of all-electric spacecraft. Since pointing accuracy is a key requirement for space platforms, suitable control systems accounting for the peculiarity of electric on/off actuators have to be devised. In this paper, an attitude control system (ACS) for spacecraft equipped with cold...

Measurements were made of a 40 cm ion-thruster plume as part of the single-string-integration-test (SSIT) activity of Phase I of the NASA’s Evolutionary Xenon Thruster (NEXT) project. The NEXT ion engine incorporates design improvements that extend NSTAR power levels and efficiencies. During SSIT, an engineering model (EM2) 40 cm engine was operated using an advanced xenon propellant system in ...

Hall current magnitude and spatial distribution are presented for the plasma discharge in the University of Michigan/Air Force Research Laboratory P5 5 kW laboratory-model Hall thruster. The data are calculated from direct, probe-based measurements of the electric field, static magnetic field, and charged particle number density. Thruster discharge voltage was fixed at 300 V and two current lev...

Detailed direct simulation Monte Carlo/particle-in-cell simulations involving the interaction of spacecraft thruster plumes with the rarefied ambient ionosphere are presented for steady thruster firings in low Earth orbit (LEO). A nominal mass flow rate is used to prescribe the rocket exit conditions of a neutral propellant species for use in the simulations. The charge exchange interactions of...