EN 16603-20-06:2014

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Vesoljska tehnika - Napajanje vesoljskih plovilRaumfahrttechnik - Aufladung von RaumfahrzeugenIngéniérie spatiale - Charges électrostatique des vehicules spatialesSpace engineering - Spacecraft charging49.140Vesoljski sistemi in operacijeSpace systems and operationsICS:Ta slovenski standard je istoveten z:EN 16603-20-06:2014SIST EN 16603-20-06:2014en01-september-2014SIST EN 16603-20-06:2014SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 16603-20-06
July 2014 ICS 49.140
English version
Space engineering - Spacecraft charging
Ingéniérie spatiale - Charges électrostatique des vehicules spatiales
Raumfahrttechnik - Aufladung von Raumfahrzeugen This European Standard was approved by CEN on 10 February 2014.
CEN and CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN and CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN and CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels © 2014 CEN/CENELEC All rights of exploitation in any form and by any means reserved worldwide for CEN national Members and for CENELEC Members. Ref. No. EN 16603-20-06:2014 E SIST EN 16603-20-06:2014

Physical background to the requirements . 65 C.1 Introduction . 65 C.2 Definition of symbols . 65 C.3 Electrostatic sheaths . 65 C.3.1 Introduction . 65 C.3.2 The electrostatic potential . 66 C.3.3 The Debye length . 66 C.3.4 Presheath . 67 C.3.5 Models of current through the sheath . 68 C.3.6 Thin sheath – space-charge-limited model . 68 C.3.7 Thick sheath – orbit motion limited (OML) model . 69 C.3.8 General case . 70 C.3.9 Magnetic field modification of charging currents . 70 C.4 Current collection and grounding to the plasma . 70 C.5 External surface charging . 71 C.5.1 Definition . 71 C.5.2 Processes . 71 C.5.3 Effects . 72 C.5.4 Surface emission processes . 72 C.5.5 Floating potential . 73 C.5.6 Conductivity and resistivity . 74 C.5.7 Time scales . 76 C.6 Spacecraft motion effects . 76 C.6.1 Wakes . 76 C.6.2 Motion across the magnetic field . 79 C.7 Induced plasmas . 80 C.7.1 Definition . 80 C.7.2 Electric propulsion thrusters . 81 C.7.3 Induced plasma characteristics . 81 C.7.4 Charge-exchange effects . 82 SIST EN 16603-20-06:2014

Charging simulation . 97 D.1 Surface charging codes . 97 D.1.1 Introduction . 97 D.2 Internal charging codes . 99 D.2.1 DICTAT . 99 D.2.2 ESADDC . 99 D.2.3 GEANT-4 . 100 D.2.4 NOVICE . 100 D.3 Environment model for internal charging . 100 D.3.1 FLUMIC . 100 D.3.2 Worst case GEO spectrum . 100 Annex E (informative) Testing and measurement. . 101 E.1 Definition of symbols . 101 E.2 Solar array testing. 101 E.2.1 Solar cell sample . 101 E.2.2 Pre-testing of the solar array simulator (SAS) . 102 E.2.3 Solar array test procedure . 104 E.2.4 Other elements . 108 SIST EN 16603-20-06:2014

Figures Figure 6-1: Applicability of electrical continuity requirements . 29 Figure 7-1: Solar array test set-up . 41 Figure C-1 : Schematic diagram of potential variation through sheath and pre-sheath. . 67 Figure C-2 : Example secondary yield curve . 73 Figure C-3 : Schematic diagram of wake structure around an object at relative motion with respect to a plasma . 77 Figure C-4 : Schematic diagram of void region . 78 Figure C-5 : Schematic diagram of internal charging in a planar dielectric . 84 Figure C-6 : Dielectric discharge mechanism. . 92 Figure C-7 :Shape of the current in relation to discharge starting point. . 92 Figure C-8 : Example of discharge on pierced aluminized Teflon® irradiated by electrons with energies ranging from 0 to 220 keV. . 93 Figure C-9 : Schematic diagram of discharge at a triple point in the inverted voltage gradient configuration with potential contours indicated by colour scale. . 94 Figure E-1 : Photograph of solar cells sample – Front face & Rear face (Stentor Sample. Picture from Denis Payan - CNES®). 102 Figure E-2 : Schematic diagram of power supply test circuit . 103 Figure E-3 : Example of a measured power source switch response . 103 Figure E-4 : Example solar array simulator . 104 Figure E-5 : Absolute capacitance of the satellite . 105 Figure E-6 : Junction capacitance of a cell versus to voltage . 107 Figure E-7 : The shortened solar array sample and the missing capacitances . 108 Figure E-8 : Discharging circuit oscillations . 109 Figure E-9 : Effect of an added resistance in the discharging circuit (SAS + resistance) . 109 Figure E-10 : Setup simulating the satellite including flashover current . 110 SIST EN 16603-20-06:2014

Tables Table 4-1: List of electrostatic and other plasma interaction effects on space systems . 21 Table 7-1: Tested voltage-current combinations . 38 Table 7-2: Typical inductance values for cables . 42 Table C-1 : Parameters in different regions in space . 67 Table C-2 : Typical plasma parameters for LEO and GEO . 78 Table C-3 : Plasma conditions on exit plane of several electric propulsion thrusters . 82 Table C-4 : Emission versus backflow current magnitudes for several electric propulsion thrusters . 82 Table C-5 : Value of Ea for several materials . 86
A need was identified for a standard that is up to date and comprehensive in its treatment of all the main environment-induced plasma and charging processes that can affect the performance of satellites in geostationary and medium and low Earth orbits. This standard is intended to be used by a number of users, with their own design rules, and therefore it has been done to be compatible with different alternative approaches. This document aims to satisfy these needs and provides a consistent standard that can be used in design specifications. The requirements are based on the best current understanding of the processes involved and are not radical, building on existing de-facto standards in many cases.
As well as providing requirements, it aims to provide a straightforward brief explanation of the main effects so that interested parties at all stages of the design chain can have a common understanding of the problems faced and the meaning of the terms used. Guide for tailoring of the provisions for specific mission types are described in Annex B. Further description of the main processes are given in Annex C. Some techniques of simulation, testing and measurement are described in Annex D and Annex E. Electrical interactions between the space environment and a spacecraft can arise from a number of external sources including the ambient plasma, radiation, electrical and magnetic fields and sunlight. The nature of these interactions and the environment itself can be modified by emissions from the spacecraft itself, e.g. electric propulsion, plasma contactors, secondary emission and photoemission. The consequences, in terms of hazards to spacecraft systems depend strongly on the sensitivity of electronic systems and the potential for coupling between sources of electrical transients and fields and electronic components. Proper assessment of the effects of these processes is part of the system engineering process as defined in ECSS-E-ST-20. General assessments are performed in the early phases of a mission when consideration is given to e.g. orbit selection, mass budget, thermal protection, and materials and component selection policy. Further into the design of a spacecraft, careful consideration is given to material selection, coatings, radiation shielding and electronics protection. SIST EN 16603-20-06:2014

EN reference Reference in text Title EN 16601-00-01 ECSS-S-ST-00-01
ECSS system - Glossary of terms
3.2 Terms specific to the present standard 3.2.1 aluminium equivalent thickness thickness of aluminium with a mass density per unit area equal to that of the material being described NOTE
The mass density is normally measured in (g cm-2). 3.2.2 auroral zone region at a latitude between 60 and 70 degrees north or south where aurorae are formed 3.2.3 deep-dielectric charging electrical charge deposition within the bulk of an external or internal material 3.2.4 dielectric pertaining to a medium in which an electric field can be maintained NOTE
Depending on their resistivity, dielectric materials can be described as insulating, antistatic, moderately conductive or conductive. The following gives a classic example of classification according to the resistivity: • more than 109 Ω m: insulating • between 102 Ω m and 109 Ω m: antistatic • between 103 Ω m and 106 Ω m: static dissipative • between 10-2 Ω m and 102 Ω m: moderately conductive • less than 10-2 Ω m: conductive SIST EN 16603-20-06:2014

on side of an object in the same direction as the plasma velocity vector 3.2.7 electrostatic pertaining to static electricity or electricity at rest 3.2.8 electrostatic breakdown failure of the insulation properties of a dielectric, resulting in a sudden release of charge and risk of damage to the dielectric concerned 3.2.9 electrostatic discharge rapid, spontaneous transfer of electrical charge induced by a high electrostatic field 3.2.10 external charging
electric charge deposition on external materials 3.2.11 fluence time-integration of the flux 3.2.12 insulator insulating dielectric 3.2.13 internal charging electrical charge deposition on internal materials shielded at least by the spacecraft skin due to penetration of charged particles from the ambient medium NOTE
Materials can be conductors or dielectrics. 3.2.14 internal dielectric charging internal charging of dielectric materials 3.2.15 ion engine propulsion system which operates by expelling ions at high velocities 3.2.16 L shell parameter of the geomagnetic field NOTE 1 It is also referred as L, and is used as a co-ordinate to describe positions in near-Earth space. NOTE 2 L or L shell has a complicated derivation based on an invariant of the motion of charged particles in the terrestrial magnetic field. However, it is useful in defining plasma regimes within the SIST EN 16603-20-06:2014

This implies that no consideration is taken of the directional distribution of the particles which can be non-isotropic. The flux at a point is the number of particles crossing a sphere of unit cross-sectional surface area (i.e. of radius). An omnidirectional flux is not to be confused with an isotropic flux. 3.2.18 outgassing rate mass of molecular species evolving from a material per unit time and unit surface area NOTE
The units of outgassing rates are g cm-2 s-1. It can also be given in other units, such as in relative mass unit per time unit: (g s-1), (% s-1) or (% s-1 cm-2). 3.2.19 plasma partly or wholly ionized gas whose particles exhibit collective behaviour through its electromagnetic field 3.2.20 primary discharge initial electrostatic discharge which, by creating a temporary conductive path, can lead to a secondary arc 3.2.21 radiation transfer of energy by means of a particle (including photons) NOTE
In the context of this Standard, electromagnetic radiation below the UV band is excluded. This therefore excludes visible, thermal, microwave and radio-wave radiation. 3.2.22 radiation belt area of trapped or quasi-trapped energetic particles, contained by the Earth’s magnetic field 3.2.23 ram volume adjacent to the spacecraft and located in the same direction of the spacecraft motion where modification to the surface or plasma can occur due to the passage of the spacecraft through the medium 3.2.24 secondary arc passage of current from an external source, such as a solar array, through a conductive path initially generated by a primary discharge
E.g. rocket, cold-gas emitter, and electric propulsion.
3.2.28 triple point
point where dielectric, metal and vacuum meet 3.2.29 upstream
on the side of the object in the opposite direction to the plasma velocity vector 3.2.30 wake volume adjacent to a spacecraft and located in the opposite direction to the spacecraft motion where the ambient plasma is modified by the passage of the spacecraft through the medium 3.3 Abbreviated terms The following abbreviated terms are defined and used within this Standard.
Abbreviation
Meaning AOCS attitude and orbital control system DGD direct gradient discharge EMC electromagnetic compatibility emf
electro-motive force EP electric propulsion ESD electrostatic discharge ETFE ethylene-tetrafluoroethylene copolymer eV electron volt (also keV, MeV)
FEEP field emission electric propulsion FEP fluoroethylene-propylene GEO
geostationary Earth orbit HEO
highly eccentric orbit ISS International Space Station SIST EN 16603-20-06:2014

low Earth orbit MEMS
micro-electromechanical system(s) MEO
medium (altitude) Earth orbit MLI
multi-layer insulation MLT
magnetic local time NASA National Aeronautics and Space Administration NGD normal gradient discharge PCB
printed circuit board PEO polar Earth orbit PTFE poly-tetrafluoroethylene PVA photo-voltaic assembly r.m.s.
root-mean-square SAS solar array simulator SPT stationary plasma thruster SSM second surface mirror UV ultra-violet light SIST EN 16603-20-06:2014

• Electric propulsion actively modifies the local environment and creates a local plasma population and modifies the current balance of the satellite that otherwise can occur. It can affect other spacecraft systems, e.g. by increased contamination.
• Electrostatic tethers make use of current collection from the ambient medium to allow a current to pass. These also change the currents passing through the system and can lead to high potentials.
Table 4-1 contains a more complete list of the various effects in which space plasma plays an important role. A quantitative description of the most important processes in spacecraft-plasma interactions is given in Annex C but a brief qualitative overview follows here. 4.1.3 Overview of physical mechanisms Surface charging occurs because electric charges (electrons and ions) of the plasma are free to move and eventually get trapped on material surfaces when they hit them. Electrons and ions provide n
...