Propagation of an ionization front in the beam channel was observed after plasma generated using a 170GHz millimeter-wave atmosphere. The propagation velocity found to be supersonic when power density greater than 75kWcm−2. momentum coupling coefficient Cm, ratio propulsive impulse input energy, measured conical and cylindrical thruster models. A Cm value 350NMW−1 recorded propagated with velocity.

The discharge current oscillation at a frequency range of 10-100 kHz in Hall thrusters was investigated with the objective extending their stable operational range. amplitude measured using two types thrusters-the anode layer type and magnetic type. found to be sensitive applied flux density, this result indicated that affected by electron mobility. An model proposed based on experimental results, predicted were agree qualitatively agreed results. This shows momentum transfer corresponding...

To extend the lifetime of commercial and scientific satellites in low Earth orbit (LEO) below (100-250 km altitude) recent years showed an increased activity field air-breathing electric propulsion as well beamed-energy systems. However, preliminary studies that propellant flow necessary for electrostatic at these altitudes exceeds mass intake possible within reasonable limits, electrode erosion due to oxygen might limit eventual thruster The pulsed plasma (PPT), however, can be successfully...

Initial flight operations of the miniature propulsion system I-COUPS (Ion Thruster and COld-gas Unified Propulsion System) are presented with problems found in space its countermeasures for them. The was developed by University Tokyo installed on a 70 kg probe, PROCYON as main to verify propulsive capability first micropropulsion deep space. successfully launched December 3rd, 2014 inserted into an orbit around Sun. PROYON project team started operation interplanetary orbit. Up today,...

Low-frequency rotating spokes are obtained in a cross-field discharge plasma using two-dimensional numerical simulations.A particle-fluid hybrid model is used to the flow configuration similar Hall thruster.It has been reported that drift-diffusion approximation for an electron fluid results ill-conditioned matrix when solving potential because of differences mobilities across magnetic field and direction E×B drift.In this paper, we employ hyperbolic approach enables stable calculation,...

Abstract Water is an attractive candidate for condensable propellants owing to its availability, handleability, and sustainability. This study proposes the use of water vapor as a propellant low-power Hall thruster, experimentally demonstrates feasibility this proposal. Based on performance estimation from plume diagnostics, thrust-to-power ratio 19 mN/kW, specific impulse 550–860 s, anode efficiency 5–8 % were obtained at power 233–358 W. From further analysis, mass utilization was found be...

A thrust stand has been developed to accurately measure produced by two types of microthrusters—a liquid propellant pulsed plasma thruster (LP-PPT) and a diode laser ablation microthruster. The impulse LP-PPT ranged from 20 80 μNs. microthruster, which is new type produces much lower range 1–10 μNs for about 1 s. mechanical noise induced the background vibrations becomes crucial problem precise estimate particularly in low measurements. data analysis method reduce effect proposed introducing...

Two-dimensional numerical model of plasma flow in a Hall thruster has been made to estimate analytically the ion-loss flux walls an acceleration channel, and obtain information about desirable configurations for good performance. The presented herein is comprised electron diffusion equation ion kinetic equation, which enables one compute electrostatic potential contours ion-beam trajectories. In first step ion-production distribution was assumed. From results it found that electric-field...

Plasma acceleration processes in an ablative pulsed plasma thruster (APPT) were investigated. APPTs are space propulsion options suitable for microspacecraft, and have recently attracted much attention because of their low electric power requirements simple, compact propellant system. The mechanism, however, has not been well understood. In the present work, emission spectroscopy, high speed photography, magnetic field measurements conducted inside electrode channel APPT with rectangular...

We have developed a three-dimensional particle model for miniature microwave discharge ion thruster to elucidate the mechanism of ECR discharges confined in small space. The consists particle-in-cell simulation with Monte Carlo collision algorithm (PIC-MCC) kinetics charged particles, finite-difference time-domain method electromagnetic fields 4.2 GHz microwaves, and finite element analysis magnetostatic permanent magnets. PIC-MCC results shown that electrons are well owing mirror magnetic...

The primary lifetime limiting factor of Hall thrusters is the wall erosion caused by ion induced sputtering, which predominated dielectric sheath and pre-sheath. However, so far only fluid or hybrid simulation models were applied to studies in this non-quasi-neutral non-equilibrium area cannot be treated directly. Thus, study, a 2D fully kinetic particle-in-cell model was presented for thruster discharge simulation. Because yet achieved due high computational cost, semi-implicit field solver...

In a pulsed plasma thruster discharge, the propellant utilization efficiency is commonly seen as weak point for its thrust performance, and low respectively. However, value depends strongly on operational settings design of itself. To access this to understand further influence parameters, method combining experimental modeling efforts proposed within paper. By using various optical methods, including high-speed camera imaging, emission spectroscopy, Mach–Zehnder interferometry, bulk...

Pulsed plasma thrusters are electric space propulsion devices which create a highly transient bulk in short-time arc discharge that is expelled to thrust. The transitional character and the dependency on properties yet be elucidated. In this study, optical emission spectroscopy Mach-Zehnder interferometry applied investigate variation of time, space, energy. Electron temperature, electron density, Knudsen numbers derived for discussed. Temperatures were found order 1.7 3.1 eV, whereas...

The propellant utilization efficiency of RAIJIN-66, a 2-kW class Hall thruster with anode layer, was investigated varying temperature to evaluate ionization length, which is the length region determined by channel and magnetic field design. During RAIJIN-66's thermally transient operation from ignition, ion beam current monitored as function using an collector plate biased negatively at 40 V. Two profiles were examined without trim yokes. From measured correlation between temperature,...

ZrB2 is a leading candidate for TPS re-entry vehicles due to its high melting point, thermal shock resistance, and low density. does not fully possess oxidation resistance necessary surviving the condition. It improves when composited with SiC can withstand intense environment caused by aerodynamic heating during re-entry. In order develop TPS, high-density ZrB2-SiC different composition ratios were fabricated spark plasma sintering (SPS). this research, related materials of UHTC, TiB2-SiC...

Understanding the six-component thrust vector of an onboard propulsion system is essential for ensuring high-quality and torque in advanced CubeSat missions, as systems may produce unintended components such side thrust, disturbance torques, or swirl torques. This paper proposes demonstrates elastic pendulum six-degree-of-freedom stand designed to measure all a CubeSats. Conventional stands struggle mN class lower due low thrust-to-weight ratio systems. The proposed addresses this limitation...

Focusing a transversely excited atmospheric CO2 laser beam in air atmospheres induced blast wave. The kinetic energy of laser-induced wave was determined from shadowgraph images shock expansion. Results showed that the fraction input is converted into decreased 0.45 to 0.2 concomitant with decrease ambient pressure 100 10 kPa. Also, it insensitive 4 13 J.

A miniature ion propulsion system is currently developed by the University of Tokyo collaborating with Next Generation Space Technology Research Association (NESTRA) in Japan. This intended for installation on 50 kg small spacecraft "HODOYOSHI-4" NESTRA under Japanese government funded project, "New Paradigm Development and Utilization Nano-satellite". The engineering models all components were assembled as an system. number operations conducted using a vacuum chamber. present specifications...

In this paper, a wireless power transmission system using magnetic resonance coupling was proposed and demonstrated for supplying at high efficiency to electrical devices in space enclosed by metal walls. This is applicable supply sensors or working the area surrounded Proposed driven frequency of 50 Hz, which selected avoid eddy current loss on surrounding metals. Firstly, resonator designs its performance limitation were described. Secondly, equivalent circuits theoretical presented....

Covers advancements in spacecraft and tactical strategic missile systems, including subsystem design application, mission analysis, materials structures, developments space sciences, processing manufacturing, operations, applications of technologies to other fields.

An experiment was conducted on a microwave rocket (repetitive-pulse millimeter-wave-beam-powered thruster) with repetitive pulses. A thruster model forced-breathing system used. The supplies fresh air from the thrust wall into thruster. pressure histories in weremeasured and propagation velocity of shock wave impulse were deduced. Results show that although identical to result for single-pulse operation at first pulse, increased after second pulse. Similarly, decreased dependence performance...