Plasma contactors for electrodynamic tether

by Michael J. Patterson

Publisher: National Aeronautics and Space Administration, Publisher: For sale by the National Technical Information Service in [Washington, D.C.], [Springfield, Va

Written in English
Published: Downloads: 339
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  • Plasma confinement.,
  • Tethered satellites.

Edition Notes

StatementMichael J. Patterson and Paul J. Wilbur.
SeriesNASA technical memorandum -- 88850.
ContributionsWilbur, Paul J., United States. National Aeronautics and Space Administration.
The Physical Object
Pagination1 v.
ID Numbers
Open LibraryOL14664291M

EPL’S Hollow Cathode Plasma Contactor (HCPC™) system supports electrodynamic tether applications and other space plasma contacting functions. The system is qualified to o plasma electron emission contacting operations. Electrodynamic tether systems can augment a spacecraft’s performance or enable capabilities that were previously unobtainable, such as energy harvesting while in the Earth’s shadow. The objectives of this research were to evaluate the feasibility, performance, trade-o s, and net bene t of electrodynamic-tether power generation for space.   This allows plasma contactor devices to collect electrons at one polarised-positive (anodic) end and eject electrons at the opposite end, setting up a current along a standard, fully insulated tether. The Plasma Motor Generator used a very similar tether system to deploy a 1/3-mile-long conducting tether and again demonstrate their utility in generating electrical power. The U.S. Naval Research Laboratory flew the mile-long Tether Physics and Survivability Experiment in , which demonstrated that long tethers could remain in space for.

Investigation of plasma contactors for use with orbiting wires The proposed Shuttle-based short tether experiments with hollow cathodes have the potential for providing important data that will not be obtained in long tether experiments. A critical property for hollow cathode effectiveness as a plasma contactor is the cross magnetic field conductivity of the emitted plasma. This device, called a electrodynamic tether, enables both the conversion of mechanical (orbital) energy into electrical energy and vice versa. In order to assure proper operation of this device, however, it is necessary to establish electrical contact between each end of the tether and the ambient space plasma.   During the tests, all subsystems functioned as designed, including the hollow cathode plasma contactor, a critical component that enables the tether system to complete its electrical circuit. required for a tether propulsion mission. (Tether propulsion is a achieved by flowing current through a conducting tether, using the ionosphere as a current return path, thus requiring electron emission.) This paper covers research in progress at the University of Michigan to develop FEAC systems for electrodynamic tethers (EDTs).

The electrodynamic tether developed within the project 'Propellantless deorbiting of space debris by bare electrodynamic tethers' (BETS) could be the answer to the space debris problem. This thin, kilometre-long, conductive tape left bare collects electrons from the ionosphere at its anodic segment and emits electrons through a plasma contactor. The EPL F unit has a moderate plasma electron emission current capability, with low gas flow and input power requirements. EPL's F (flight) hollow cathodes. GOVERNMENT/SCIENCE APPLICATIONS The HCPC will be used on the ProSEDS mission as a plasma contactor for an electrodynamic tether. Flight is planned for it is likely that the system will also have to rely on the ISSÕs plasma contactor as well, or on a second dedicated contactor, since currents over the 10 A rating of the contactors could be required. Before an operational electrodynamic tether reboost system for the ISS can be designed, a series. The top of the diagram, point A, represents the electron collection bottom of the tether, point C, is the electron emission rly, and represent the potential difference from their respective tether ends to the plasma, and is the potential anywhere along the tether with respect to the plasma. Finally, point B is the point at which the potential of the tether is equal to the plasma.

Plasma contactors for electrodynamic tether by Michael J. Patterson Download PDF EPUB FB2

Plasma contactors could be used to ground satellites to space plasma to acquire a flow of electrons to propel or power the satellites. A tether would cut across geomagnetic field lines, producing a. The role plasma contactors play in effective electrodynamic tether operation is discussed.

Hollow cathodes and hollow cathode-based plasma sources have been identified as. Get this from a library. Plasma contactors for electrodynamic tether. [Michael J Patterson; Paul J Wilbur; United States. National Aeronautics and Space Administration.].

Copynght COSPAR PLASMA CONTACTOR DESIGN FOR ELECTRODYNAMIC TETHER APPLICATIONS Paul J. Wilbur and Thomas G. Laupa Department of Mechanical Engineering, Colorado State University, Fort Collins, COU.S.A. ABSTRACT The plasma contacting process is described and experiments are discussed that suggest the key role that cold ions play in establishing a low impedance plasma bridge that can conduct current in either direction between a contaotor electrode Cited by: The role plasma contactors play in effective electrodynamic tether operation is discussed.

Hollow cathodes and hollow cathode-based plasma sources have been identified as leading candidates for the electrodynamic tether plasma contactor. Present experimental efforts to evaluate the suitability of these devices as plasma contactors, conducted concurrently at NASA Lewis Research Center and Cited by: 6.

Plasma contactors have been proposed as a means of making good electrical contact between biased surfaces, such as found at the ends of an electrodynamic tether, and the space environment. A plasma contactor is a plasma source which emits a plasma cloud which facilitates the electrical connection.

A Brief Overview of Electrodynamic Tethers Laboratory simulation of the itneraction between a tethered satellite system and the ionosphere Il Nuovo Cimento C, Vol. 15, No. 5 Theory of plasma contactor neutral gas emissions for electrodynamic tethers. The plasma properties and electron emission characteristics of near-zero differential resistance of hollow cathode-based plasma contactors with a discharge chamber Physics of Plasmas, Vol.

21, No. 8 Current–voltage characteristics of a cathodic plasma contactor with discharge chamber for application in electrodynamic tether propulsion. The role plasma contactors play in effective electrodynamic tether operation is discussed.

Hollow cathodes and hollow cathode-based plasma sources have been identified as leading candidates for the electrodynamic tether plasma contactor. Present experimental efforts to evaluate the suitability of these devices as plasma contactors are reviewed.

Plasma kinetics issues in an ESA study for a plasma laboratory in space B M Annaratone, A Biancalani, D Bruno et al.-Potentials of surfaces in space E C Whipple-Current voltage characteristics of a cathodic plasma contactor with discharge chamber for application in electrodynamic tether propulsion Kan Xie, Rafael A Martinez and John D Williams.

Parks and I. Katz, “Theory of Plasma Contactors for Electrodynamic Tethered Satellite Systems,” J. of Spacecraft and Rockets, Vol. 24, pp. – ().

ADS CrossRef Google Scholar [8]. Electrodynamic tether basics A non-reiativistic transformation relates throughout the electric fields in frames moving with SC and local ambient plasma, E {tether frame)-E {plasma= i =(v- frame))x¡)v, (1) m pi where v, v, are the velocities of S/C (and tether) and plasma.

Plasma contactors have been proposed as a means of making good electrical contact between biased surfaces, such as those found at the ends of an electrodynamic tether or a space vehicle charging control, and plasma in the space environment [1, 2].Plasma contactors function by emitting a plasma cloud which facilitates the electrical connection.

The ring-cusp configuration selected for the plasma contactor created a Gauss axial field near the cathode orifice, along with a large-volume Gauss magnitude pocket in the stage. A baseline ion energy cost of ≈ eV/ion was measured in the ionization stage when no electrons were emitted to the vacuum chamber wall.

power to be handled. The current-voltage characteristic of contactors would be measured. With the anode switched off, the wire itself should collect a current over 5 A at day conditions, providing a thrust of N at a kW power. Keywords: Electrodynamic Tethers, Plasma Contactors 1. INTRODUCTION.

plasma contactors were part of a current loop that passed from the ionosphere through the FEP, the tether, the load, the battery, the NEP, and back to the plasma (see Figure 1). One of the plasma contactors acted as a positive current. The formation of electron emission-bias voltage (I-V) characteristics of near-zero differential resistance in the cathodic plasma contactor for bare electrodynamic tether applications, based on a hollow cathode embedded in a ring-cusp ionization stage, is studied.

The existence of such an I-V regime is important to achieve low impedance performance without being affected by the space plasma.

To determine the effects of different plasma contactors, a simulation tool was created that is called SimBETS, which is short for Simulation of a Bare Electrodynamic Tether System.

This tool was designed to predict EDT induced decay orbits based on atmospheric and ionospheric models for circular and elliptic orbits under 1, km.

The present invention comprises apparatus and methods for using and controlling electrodynamic tethers. The apparatus taught by the present invention uses an interconnected multiwire (compared to the long, narrow single wires of the prior art) conductive tether whose area maximizes electrodynamic drag while simultaneously minimizing the Area-Time-Product swept by the tether during its.

Both plasma contactors and large conductive surfaces at the ends of the tether provide this contact, establishing a current loop through the tether, external plasma and the ionosphere around the.

Electrodynamic tethers (EDTs) are long conducting wires, such as one deployed from a tether satellite, which can operate on electromagnetic principles as generators, by converting their kinetic energy to electrical energy, or as motors, converting electrical energy to kinetic energy.

Electric potential is generated across a conductive tether by its motion through a planet's magnetic field. An apparatus as in claim 1 wherein the electrodynamic tether includes at least one plasma contactor to increase an electrical connection between the conducting portion of the tether and the space plasma.

An apparatus as in claim 1 including an end mass on the far end of the electrodynamic tether. plasma contactors at its ends. As the system orbits the Earth with a velocity v0, it cuts across the geomagnetic field B lines. An electromotive force Em = \v0 X B\ is induced along the tether, generating a current I across any interposed useful load RL- Typical motional fields ranging from to volts per kilometer of tether.

Under the Phase-1 effort, the preliminary work to demonstrate the feasibility of the SOLEX concept was accomplished. The intent of the proposed Phase-II effort is to develop a flight-level design for a SOLEX plasma generator, for electrodynamic tether systems, and fabricate an Engineering Unit test device that is appropriate for flight validation.

along the tether itself, eliminating the need for a large, massive and/or high-drag sphere or a resource-using plasma contactor at the upper end of the tether.

This sub­ stantially reduces the center of gravity shift in both cases and reduces the cost and complexity in the case of the active contactor. Plasma Sources Science and Technol no. 1 (): Derek M. Blash and John D.

Williams, "Determination of Hollow Cathode Plasma Contactor System Requirements using an Electrodynamic Tether System Simulation Tool," 13th International Spacecraft Charging Technology Conference, Pasadena, California, June high power thermionic emitters and gas plasma contactors that use a consumable (Xe gas, typically) for space electrodynamic tether systems and other space electric propulsion systems requiring low-power neutralizers.

Example cold-cathode electron field emission technologies include Spindt-type cathodes and. Electrodynamic Tether as a Thruster for LEO Mission Applications We present the analyses of efficiency of a tether system with grid-sphere contactor as a thruster and consider the possible application of such a design for the ISS and MXER facility plasma density 3 10 11 −3.

Electrodynamic Tether as a Thruster for MXER Studies plasma. Because active plasma contactors require expenditure of propellant and may require significant additional mass, the bare wire tether technology is also being considered for the MXER tether.9 The choice of a tether design.

Xie, K., Martinez, R.A., and Williams, J.D. Current voltage characteristics of a cathodic plasma contactor with discharge chamber for application to electrodynamic tether propulsion, accepted Feb.

by Journal of Physics D: Applied Physics, in press. Plasma Contactor = Electron Emitter electrodynamic propulsion tether. In this case electrical power supplied by a set of solar arrays is used to run a current through the tether. If the direction of the current is opposite to the direction it would flow in case of an electrodynamic drag tether, the resulting Lorentz force will also work in the.

This paper studied the dynamic characteristics of electrodynamic tethered satellite with consideration of coupled multiphysics field for orbital boost maneuver by a fully insulated electrodynamic tether (EDT).

We proposed a simplified analytical nonlinear current–voltage circuit method based on the Parker–Murphy model to evaluate the real-time electric current-carrying tether.additional power supply and plasma contactors is necessary.

The efficiency of orbital boost maneuver with different radius of contactor and voltage of power supply are compared and contrasted. Through these models, it is shown that tether current is more easily affected by the Earth’s magnetic field and plasma density fluctuation.