structural electrophysical model
the transitive currents
The radio-electronic equipment established onboard spacecraft, is improved towards introduction of new technologies, increase of clock frequencies of processing of the information, expansion of a spectrum of processed signals. Are simultaneously minimized mass-dimensional equipment parameters, the density of its configuration in volume spacecraft increases. The increase tendency in integration at placing of elements and devices, electronic blocks and systems of different function leads to necessity of the decision of problems on protection of onboard radio-electronic equipment against electrostatic discharge. A special role processes electrization thus play surfaces spacecraft causing electrostatic discharge (ESD) on a surface of blocks and cable systems. ESD, arising owing to differential charge up spacecraft, are sources of electro magnetic interference (EMI), influencing separate elements and devices and (or) onboard systems as a whole.
The analysis of methodology of control and protection against a static electricity of the airborne electronic equipment allows to define the primary goals for a solution of a problem of increase of reliability spacecraft:
Creation and use in orbital conditions sensors equipments for control of electrostatic charges spacecraft;
Creation and application of models electrization spacecraft for the various orbital conditions, allowing to define areas and installation sites sensors equipments;
Working out of methodology of processing, the analysis, parameters electrization by means of the created control devices and model electrization, and also a choice of ways of antistatic protection.
For modeling electrization spacecraft construction is necessary: geometrical, structural electrophysical model electrization spacecraft. Creation of such model will allow:
To predict abnormal places of occurrence of electrostatic categories both between separate surfaces spacecraft, and between surface spacecraft and surrounding plasma layer;
To define installation areas sensors equipments;
To develop algorithm of processing, the analysis, modeling parameters electrization spacecraft and a protect estimation.
As a result of modeling probably to define size parasites in radio-electronic equipment and an onboard cable network laid on surface spacecraft, and to make recommendations about application of passive protection against these parasites.
Creation of electrophysical model will give the chance to use sensors equipment and on the basis of the information received from it and to choose the most suitable type of protection.
The arrangement sensors equipments on design spacecraft is accepted on the basis of the results received on the basis of calculations of structural electrophysical model.
On the basis of the information received on telemetry from sensors of equipment, the decision on application of one of variants of active protection which has been established on spacecraft is made.
Use of active means of neutralization of an electric charge in instrument compartments and cases of equipment spacecraft on the basis of the accepted data from sensors equipments will allow to react operatively to change of electrostatic conditions on surfaces and to prolong active lifetime spacecraft.
The above described algorithm of modeling of influence electrization allows to formulate at design stage spacecraft specifications on stability of the electronic blocks having an exit on external surface spacecraft by means of onboard cable network, to pulse hindrances on inputs of these blocks.
The stated approach allows to model the processes proceeding at ESD, and, thus, on the basis of results of these processes to make correct placing sensors equipments.
Methodology working out on monitoring of electrostatic conditions assumes the decision of following problems:
a) creation of structural electrophysical model consists of three stages:
construction of three-dimensional geometrical model spacecraft from base elements;
transformation of three-dimensional surface spacecraft;
calculation of transitive currents and visualization of results of calculation on spatial model spacecraft.
b) arrangement sensors equipments on design spacecraft.
In the given work the short description of features of construction of models of processes electrization spacecraft in interests of increase of their reliability in orbital conditions is resulted.
Process modeling electrization surfaces spacecraft allows to yield well-founded results for application of active or passive protection, taking into account the telemetering information received from sensors equipments of the onboard monitoring system electrization.
Besides, results of such modeling contain additional toolkit in the form of the schemes, allowing to analyse results of modeling taking into account the statistical material saved up by the time of tests on correlation communication between anomalies in functioning of space vehicles and their possible effects electrization.
Modeling electrization, the way described above, can be applied both to operating spacecraft, and to projected objects as the analysis of firmness functioning spacecraft allows to plan design decisions for perspective workings out.