Plasma Field Telemetry for Hypersonic Flight (original) (raw)
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Modeling of Electromagnetic Manipulation of Plasmas for Communication During Reentry Flight
Journal of Spacecraft and Rockets, 2010
Radio blackout that occurs during hypersonic reentry flight is an important issue for the operation of the vehicle. Since the radio blackout problem is caused by a high plasma number density around a vehicle, it is necessary to manipulate the plasma to allow communication. We suggest a configuration of an ExB layer as a reentry blackout mitigation method. The suggestedExB layer configuration with a two-dimensional magnetic field is simulated using the thermalized potential model and the Poisson-like model in order to illustrate the effectiveness of this approach as a mitigation method. The numerical model uses a magnetohydrodynamics approximation and is solved using a finite volume method with a Riemann solver. The results of the numerical model are assessed using available experimental results.Astrong plasma density reduction is obtained when the high electric and magnetic fields are applied near the cathode. The manipulated plasma region provides a possibility to communicate through a plasma layer during a reentry blackout.
Modeling Radio Communication Blackout and Blackout Mitigation in Hypersonic Vehicles
Journal of Spacecraft and Rockets, 2015
A procedure for the modeling and analysis of radio communication blackout of hypersonic vehicles is presented. A weakly ionized plasma generated around the surface of a hypersonic reentry vehicle traveling at Mach 23 was simulated using full Navier-Stokes equations in multi-species single fluid form. A seven species air chemistry model is used to compute the individual species densities in air including ionization -plasma densities are compared with experiment. The electromagnetic wave's interaction with the plasma layer is modeled using multi-fluid equations for fluid transport and full Maxwell's equations for the electromagnetic fields. The multi-fluid solver is verified for a whistler wave propagating through a slab. First principles radio communication blackout over a hypersonic vehicle is demonstrated along with a simple blackout mitigation scheme using a magnetic window.
PLASMA DENSITY REDUCTION USING ELECTROMAGNETIC E×B FIELD DURING REENTRY FLIGHT
As a vehicle reenters or flies at hypersonic speed through the atmosphere, the surrounding air is shock heated and becomes weakly ionized. The plasma layer thus formed causes a communication problem known as ‘radio blackout’. At sufficiently dense plasma conditions, the plasma layer either reflects or attenuates radio wave communications to and from the vehicle. In this paper, we propose an electromagnetic field configuration as a method to allow communication through the plasma layer. Theoretical models show that this may address the blackout problem under a range of conditions. Preliminary experimental results are also presented.
Reentry vehicles: evaluation of plasma effects on RF propagation
2013
In the frame of communication technology relevant to the re-entry vehicles, the communication black-out occurring in the presence of plasma is one of the main challenging issues. The re-entry plasma is a complex physical system, where the ionization derives from a shock-wave and non-equilibrium phenomena. As discussed elsewhere, the time scales of plasma dynamics (including its evolution along mission trajectory) and radio wave propagation are well separated so that radio wave propagation is solved at an appropriate number of time "snapshots" in which plasma dynamics is held unchanged and considered as known. In this activity, a consistent effort has been devoted to model the electromagnetic problem. For the involved range of oprative frequencies and expected densities, the plasma can be considered as an inhomogeneous dielectric. The associated electromagnetic problem is solved in two steps, via use of the field equivalence principle. The vehicle-plasma system is substitut...
Open Aerospace …, 2010
An aero-thermo-chemical model is developed to simulate the flowfield, including ionization, around atmospheric re-entry configurations, and its interactions with radio-frequency communication signals (e.g. GPS). The model is successfully validated against literature in-flight measurements of the electron number density, and then applied to the re-entry of recently proposed concepts of slender configurations. The advantages of using sharp and slender geometries for re-entry applications, with respect to radio communication problems, are analyzed and discussed. In addition, an experimental test-bed in an arc-jet plasma wind-tunnel has been setup to reproduce on ground the plasmaradiofrequency interaction. The capability to duplicate on-ground the ionization levels encountered during re-entry has been successfully demonstrated. A numerical model of an Argon plasma jet in chemical and thermal non-equilibrium has also been developed, for numerical rebuilding of the experiments. Both electron number densities and electron temperatures have been successfully correlated, demonstrating the ability of arc-jet facilities, integrated with proper numerical tools, to correctly deal with problems of communication attenuation/black-out.
AIP Advances
Plasma sheaths enveloping hypersonic vehicles could yield a communication blackout. Many previous studies have shown that the electromagnetic wave in an extremely high frequency (EHF) band could penetrate a hypersonic plasma sheath effectively. In other words, the EHF communication could be a potential solution to the communication blackout problem. Nevertheless, most of those works used to concern only the EHF signal attenuation. In addition, those works normally treated plasma sheaths as a static plasma layer. However, plasma sheaths always keep evolving. In the present study, the modulated EHF signal propagation in a time-varying plasma sheath was investigated numerically. The plasma sheath was obtained with a hypersonic hydrodynamical model that has been utilized in previous studies. The EHF signal propagation was modeled based on theories of geometrical optics. The frequencies studied are 94, 140, and 225 GHz. The investigation revealed that not only signal attenuation but also...
Mitigation of Communication Blackout During Re-Entry Using Static Magnetic Field
Progress In Electromagnetics Research B, 2015
During re-entry into earth's atmosphere, a spacecraft suffers from loss of communication with the ground control station, known as communication blackout, due to formation of plasma around the re-entry spacecraft. This paper presents the theory and analysis of the communication blackout and its mitigation using static magnetic field method. The interaction between electromagnetic waves and plasma in presence as well as absence of magnetic field is described to determine the effects of plasma sheath on the spacecraft re-entering into the atmosphere. An analysis is done to determine the effectiveness of this mitigation technique for a typical re-entry spacecraft and the strength of magnetic field required to establish the communication link between the re-entry spacecraft and the ground station is obtained. 1. INTRODUCTION When a reusable launch vehicle or manned/unmanned space flight re-enters the atmosphere of earth, a layer of plasma is formed around the vehicle, known as plasma sheath. It is a result of shock wave produced due to excessive heating of air surrounding the vehicle. This plasma can interrupt the radio communication between the re-entry vehicle and the ground based stations. This critical period of time when the communication between the re-entry spacecraft and the ground stations is lost is known as Communication Blackout, which can vary from few seconds to several minutes, depending upon various factors, like vehicle configuration, flight velocity, atmospheric density and angle of attack [1]. The loss of communication between the re-entry vehicle and its ground station is critical due to following reasons: (i) This period of time may coincide with the vital portion of manoeuvre phase of the re-entry spacecraft. (ii) The absence of communications and control during these few critical minutes, when spacecraft encounters the most extreme temperatures and pressures, is highly undesirable. (iii) In the event of an accident/failure during re-entry, the data collected during this phase may be invaluable for diagnosing the cause of failure and improving flight safety in future missions.