TECHNICAL REPORT ISO/TR 20590 First edition 2017-02 Space systems - Debris mitigation design and operation manual for launch vehicle orbital stages Systèmes spatiaux - Conception pour l’attenuation des débris et manuel d’utilisation étages orbitaux pour les véhicules de lancement Reference number ISO/TR 20590:2017(E) © ISO 2017 ISO/TR 20590:2017(E) COPYRIGHT PROTECTED DOCUMENT © ISO 2017, Published in Switzerland All rights reserved Unless otherwise specified, no part o f this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission Permission can be requested from either ISO at the address below or ISO’s member body in the country o f the requester ISO copyright o ffice Ch de Blandonnet • CP 401 CH-1214 Vernier, Geneva, Switzerland Tel +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org ii © ISO 2017 – All rights reserved ISO/TR 20590:2017(E) Page Contents Foreword v Introduction vi Scope Normative references Terms and definitions Related documents and abbreviated terms and symbols Requirements in ISO Standards and system-level methodologies for complying with the requirements 4.1 4.2 4.3 4.4 4.5 4.6 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Overview of ISO debris-related standards ISO debris-related standards for launch vehicles as of 2016 Spacecraft related ISO standards Other ISO standards Other documents Abbreviated terms General Refrain from releasing objects 5.2.1 Requirements 5.2.2 Work breakdown 5.2.3 Identification o f released objects and design measures Break-up prevention 5.3.1 Requirements 5.3.2 Work breakdown 5.3.3 Identification o f the sources o f break-up 5.3.4 Design measures 5.3.5 Monitoring during operations 5.3.6 Preventive measures for break-up after mission completion Disposal manoeuvres at the end of operation 5.4.1 Requirements 5.4.2 Work breakdown 10 5.4.3 LEO mission 11 5.4.4 GEO mission and other high-elliptical orbit missions 12 Ground safety from re-entering objects 13 5.5.1 Requirements 13 5.5.2 Work breakdown 13 5.5.3 Preventive measures 14 5.5.4 Risk detection: Notification 15 5.5.5 Countermeasures: Controlled re-entry and Monitoring 16 Collision avoidance 16 Reliability and QA 16 Debris-related work in the development lifecycle 17 6.1 6.2 6.3 6.4 6.5 6.6 6.7 General 17 Concept of debris-related work in each phase 17 Mission Requirements Analysis Phase (pre-phase A) 20 6.3.1 General 20 6.3.2 Debris-related works 20 Feasibility phase (phase A) 20 Definition phase (phase B) 20 6.5.1 Work in phase B 20 6.5.2 Work procedure 21 Development phase (phase C) 21 Production phase (phase D) 22 6.7.1 Work in phase D 22 © ISO 2017 – All rights reserved iii ISO/TR 20590:2017(E) 22 6.7.3 Launch service 22 Utilization phase (phase E) 22 Disposal Phase (phase F) 22 6.7.2 6.8 6.9 Qualificatio n review System-level considerations 23 23 f 23 Subsystem / Component design and operation 23 8.1 General 23 8.1.1 Scope 23 f 24 24 8.2.1 Debris-related design 24 f 25 8.2.3 Considerations for component design 26 28 8.3.1 Debris-related designs 28 f 28 29 8.4.1 Debris related design 29 29 f 8.4.3 Consideration in component design 29 30 8.5.1 Debris-related designs 30 f 30 8.5.3 Considerations for component design 30 31 8.6.1 Design measures 31 31 f 8.6.3 Considerations for component design 31 32 f f 8.7.1 Debris-related designs 32 f 32 8.7.3 Considerations for component design 32 Bibliography 33 7.1 Sys tem des ign 7.2 M is s io n analys is 8.1 8.2 o r the guidance and co ntro l s ub sys tem C o ns ideratio ns o r p o wer s ub sys tems D es ign o co mmunicatio n s ub sys tem Practices o r s tructure s ub sys tem Range s a ety s ub sys tem (S el - des truct s ub sys tem) 8.7.2 iv C o ns ideratio ns S tructure s ub sys tem 8.6.2 8.7 o r p ro p uls io n s ub sys tems C o mmunicatio n s ub sys tem 8.5 8.6 C o ns ideratio ns E lectric p o wer- s up p ly s ub sys tem 8.5 o r realizing them Guidance and co ntro l s ub sys tem 8.3 8.4 D eb ris - mitigatio n meas ures and s ub sys tem- level actio ns Pro p uls io n s ub sys tem 8.2 8.3 o r each launch mis s io n C o ns ideratio n o r co mmand des tructio n s ub sys tem © ISO 2017 – All rights reserved ISO/TR 20590:2017(E) Foreword The International Organization for Standardization (ISO) is a worldwide federation of national standards bodies (ISO member bodies) International Standards are generally prepared by ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to represent that committee International organizations, both governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters o f electrotechnical standardization The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part In particular, the different approval criteria needed for the di fferent types o f ISO documents should be noted This document was dra fted in accordance with the editorial rules of the ISO/IEC Directives, Part (www.iso org/directives) Attention is drawn to the possibility that some o f the elements o f this document may be the subject o f patent rights ISO shall not be held responsible for identi fying any or all such patent rights Details o f any patent rights identified during the development o f the document will be in the Introduction and/or on the ISO list of patent declarations received (www.iso org/patents) Any trade name used in this document is in formation given for the convenience o f users and does not constitute an endorsement For an explanation on the meaning o f ISO specific terms and expressions related to the formity assessment, as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) The committee responsible for this document is ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 14, Space systems and operations © ISO 2017 – All rights reserved v ISO/TR 20590:2017(E) Introduction Coping with debris is essential to preventing the deterioration of the orbital environment and ensuring the sustainability o f space activities E ffective actions can also be taken to ensure the sa fety o f those on the ground from re-entering objects that were disposed of from Earth orbit ISO 24113 “Space debris mitigation requirements,” and other ISO documents, introduced in Clause 4, were developed to encourage debris mitigation Table shows those requirements together with the recommendations in the United Nations Space Debris Mitigation Guidelines and the Inter-Agency Space Debris Coordination Committee (IADC) Space debris guidelines referred to in the United Nations (UN) guidelines Table lists the main debris mitigation requirements defined in the standards and compares them to equivalent recommendations published by the UN and the IADC In Clause 5, the main space debris mitigation requirements are reported and analyzed In Clause 6, the guidance for li fe-cycle implementation o f space debris mitigation related activities are provided In Clause 7, the system level aspects stemming from the space debris mitigation requirements are highlighted; while in Clause 8, the impacts at subsystem and component levels are detailed In this document, where the content is not directly required by existing ISO Standards but considered relevant to launch vehicle orbital stages operations or design and debris mitigation, it is labelled as “[Information].” vi © ISO 2017 – All rights reserved © ISO 2017 – All rights reserved Table — Comparison of ISO debris-related documents with UN and IADC space debris mitigation guidelines Measures Limiting debris generation Released objects General measures for avoiding the release of objects Slag from solid motors Combustion products from p yro te ch n ic s On-orbital breakups Disposal at end-of-operations GEO Intentional destruction Accidental break-ups during operation Post-mission break-up (Passivation, etc.) Reorbit at end of operation ISO Standards (or Technical Reports) ISO 24113, 6.1.1 ISO 24113, 6.1.2 2, 6.1.2 ISO 24113, 6.1.2 (Combustion Products < mm) ISO 24113, 6.2 ISO 24113, 6.2 ( P rob ab i l ity < 10 ISO 24113, 6.2 -3 ) (Detailed in ISO 16127) UN Guidelines IADC Guidelines - - Recommendation-4 Recommendation-2 5.2.3 5.2.2 (Monitoring) 5.2.1 Recommendation-1 Recommendation-5 5.1 (Detailed in ISO 26872) 6.3.2.1: General Requirement 6.3.2.2: 235 km+ (1 000•Cr•A/m), e < 0,003 Recommendation-7 5.3.1 (No quantitative requirements) 235 km+ (1 000•Cr•A/m), Note: ITU-R S.1003-1 recommends; 235 km + 1,000 Cr*A/M e < 0,003 Here, A[m ], M[kg], Cr[-] Reduction of orbital lifetime ISO 24113, 6.3.3 (Detailed in ISO 16164, 16699) Recommendation-6 5.3.2 6.3.3.1: Orbital lifetime after end of operation (No quantitative requirements) (Recommend 25 ISO 24113, 6.3.2 : Succe s s P ro b ab i l ity > ,9 LEO ye a rs) < ye a rs Collision avoidance for large debris Protection from the impact of micro-debris : Succe s s P ro b ab i l ity > ,9 ISO 24113, 6.3.3.2 (f) (Gu a nte e 10 ye a rs o f non-i nter ference) ISO 24113, 6.3.3.2 (a) ~ (e) ISO 24113, 6.3.4 (Detailed in ISO 27875) ISO/TR-16158 (fo r a s s e s s ment o n l y) ISO 16126 (for a s s e s s ment on l y) Mentioned in Recommendation-6 5.3.2 -Included in Recommendation-6 Recommendation-3 5.3.2 5.3.2 5.4 5.4 vii ISO/TR 20590:2017(E) Re-entry Transfer to out of protected region Other options Avoidance of ground casualties TECHNICAL REPORT ISO/TR 20590:2017(E) Space systems - Debris mitigation design and operation manual for launch vehicle orbital stages Scope This document contains non-normative information on the design and operational practices for launch vehicle orbital stages for mitigating space debris T h i s c u ment c an b e u s e d to gu ide engi ne ers i n the appl ic ation o f the fam i ly o f s p ace debri s m itigation standards (see 4.2 f are designed, operated, and disposed of in a manner that prevents them from generating debris throughout their orbital lifetime ) to re duce the grow th o T he s p ace debri s b y en s u ri ng that l au nch veh icle orbita l s tage s Normative references fol lowi ng c u ments are re ferre d to i n the tex t i n s uch a way th at s ome or a l l o f thei r content s titute s re qu i rements o f th i s c u ment For date d re ference s , on ly the e d ition cite d appl ie s For u ndate d re ference s , the late s t e d ition o f the re ference d c ument (i nclud i ng a ny amend ments) appl ie s There are no normative references in this document Terms and definitions For the pur p o s e s o f th i s c u ment, the term s a nd defi n ition s given i n I S O 10 79 : 01 a nd the o ther standards listed in 4.2, 4.3, and 4.4 ISO and IEC maintain terminological databases for use in standardization at the following addresses: — IEC Electropedia: available at http://www.electropedia org/ — ISO Online browsing platform: available at http://www.iso org/obp apply 4.1 Related documents and abbreviated terms and symbols Overview of ISO debris-related standards The requirements, recommendations, and best practices for mitigating debris generation and preventing other debris related problems are examined in this clause Figure shows a general diagram of major ISO documents related to debris © ISO 2017 – All rights reserved ISO/TR 20590:2017(E) Figure — Structure of major debris related standards for orbital stages 4.2 ISO debris-related standards for launch vehicles as of 2016 The following ISO Standards have been developed to address space debris mitigation Readers are f http://www.iso org/iso/ store htm Also for 4.3 4.5) (1) ISO 24113:2011, Space systems — Space debris mitigation requirements (2) ISO 27852:2011, Space systems — Estimation of orbit lifetime (3) ISO 16699:2015, Space systems — Disposal of orbital launch stages (4) ISO 20893, Space systems — Prevention of break-up of orbital launch stages exp e c te d to fi rm the mo s t up to date l i s t o I S O s tanda rd s (avai lable at − 4.3 Spacecraft related ISO standards (1) ISO 16127:2014, Space systems — Prevention of break-up of unmanned spacecraft (2) ISO 16164:2015, Space systems — Disposal of satellites operating in or crossing LEO (3) ISO 26872:2010, Space systems — Disposal of satellites operating at geosynchronous altitude © ISO 2017 – All rights reserved ISO/TR 20590:2017(E) 6.3 Mission Requirements Analysis Phase (pre-phase A) 6.3.1 General T he mai n pu rp o s e o f th i s ph as e i s to identi fy the concep t o f a l au nch veh icle From the p oi nt o f view o f debris-related issues, the following items are conducted during this phase: I denti fy the debri s-m itigation re qui rements i n I S O Sta ndard s , nationa l regu lation s , e tc (1) I denti fy (2 ) s a fe ty, rel iabi l ity, and qua l ity re qu i rements m itigation me as u re s , i nclud i ng prevention o f the 6.3.2 to en s ure fragmentation the abi l ity to conduc t debri s - c au s e d b y ma l fu nc tion s , e tc Debris-related works D ebri s-m itigation re qu i rements debri s -relate d re giona l and rep or te d i n I S O nationa l 41 regu lation s , I f there a re o ther appl ic able are identi fie d they are also s idere d, and the fi na l set of re qu i rements i s identi fie d ISO 24113 f f f address collision avoidance, but the UN Debris Mitigation Guidelines recommends to estimate and limit f adjustment of the launch time, if available orbital data indicates a potential collision (See 4.5 (1)) (as o 016) pres ents re qui rements only the prob abi lity o 6.4 or mitigati ng the generation o debri s It es not accidental col l is ion with known obj e c ts during the s ys tems ’ launch phas e, and cons ider Feasibility phase (phase A) T he output o f th i s ph as e is refle c te d in the s ys tem re qu i rements c u ment (s p e ci fic ation s) T his c u ment i s reviewe d du ri ng the “s ys tem re qu i rement defi n ition review (S RR) ” T he variou s p o s s ible concep ts are s tud ie d to me e t the defi ne d obj e c tive s M i s s ion re qu i rements , debri s relate d re qu i rements , and o ther regu lator y ru le s are ta ken i nto accou nt The following aspects are considered: (1) The requirements regarding not releasing objects provide normative content for the selection of typ e s o f propu l s ion s ys tem s (s ol id , hybrid, or l iqu id) (2 ) B re a k-up preventive re qu i rements provide normative content on ma s s a l lo c ation due to tan k de s ign, s a fe ty fac tors , for s a fe ty de s ign concep t (i mp ac t the b as ic figu ration o f s tagi ng s truc tu re (3 ) D i s p o s a l re qu i rements provide normative content (4) Re - entr y s a fe ty re qui rements provide normative content and the allocation of function for each stage for the a nd margi n s , e tc ) and rel iabi l ity de s ign for the de s ign o f a s s o ci ate d s ub - s ys tem s rel ate d to control le d re - entr y, i nclud i ng the rad i ation rd ne s s de s ign D 6.5.1 T he e f i n i t i o n p h a s e ( p h a s e B for avion ics ) Work in phase B output o f th i s ph as e is refle c te d i n the “s ys tem s p e ci fic ation s ” a nd “s ub s ys tem s p e ci fic ation s (d ft) ” T hey a re reviewe d duri ng the S D R In th i s ph as e, the s ys tem re qu i rements are defi ne d in a re ference fu nc tiona l s p e c i fic ation and a prel i m i na r y te ch n ic a l s p e ci fic ation at the s ys tem level a s s p e ci fie d i n I S O 143 0 -1 [I n formation 1] : charac teri s tic s , T he as pri ncip a l wel l as the figu ration s , op erationa l i nclud i ng concep t, phys ic a l, veri fic ation func tiona l, concep t, and a nd p er formance proj e c t re s ou rce s (development regime, budget, and scheduling) are chosen in this phase Therefore, the decision to i mplement a re - entr y control fu nc tion that cou ld i mp o s e a he av y bu rden on the fu nc tiona l and p er formance charac teri s tic s i s fi xe d no later tha n i n th i s phas e 20 © ISO 2017 – All rights reserved ISO/TR 20590:2017(E) The concept to comply with ISO 24113 should be defined in the “space-debris-mitigation plan (SDMP)” as defined in ISO 24113, Clause 6.5.2 Work procedure (1) Basic concept Excessive low reliability is not only un favourable on its own, but also undesirable, due to its e ffects on the orbital environment in case it causes a malfunction or fragmentation Therefore, a mission assurance philosophy is developed (2) Consideration o f debris mitigation measures in system design a) In the allocation o f propellant, the propellant for disposal manoeuvers and controlled re-entry manoeuvers are taken into account b) In the allocation o f reliability, the probability o f break-up during operation is considered c) In planning the controlled re-entry, the manoeuver sequence and the function and per formance o f the propulsion subsystem are studied by the end o f this phase Moreover, the total system, including the ground control and monitoring system, is studied by the end o f this phase 6.6 Development phase (phase C) In this phase, the system specifications are allocated at the component and part levels In the specifications, the functional and per formance requirements are defined to satis fy the SDMP During the above procedure, the following are considered: (1) Reliability and QA Again, reliability and QA for orbital stages are essential not only for mission completion, but also for the sa fety o f the other operating S/C in orbit (See ISO 16127, 5.1) (2) Break-up prevention and sa fety control Major causes o f break-up are explosion o f the propulsion subsystem and the rupture o f high-pressure vessels To prevent those causes of break-up, appropriate design measures (prevention of the mixture of bi-propellants, robust structural design, etc.) are essential (3) Prevent the release of parts According to ISO 24113, 6.1, orbital stages are designed so as not to release objects that will become orbital debris (such as clamp bands, nozzle closures, combustion-related products, igniters for solid motors, etc.) during normal operations (4) Disposal after the end of operation During the design phase, su fficient propellant is allocated to carry out the disposal manoeuver (5) Sa fety assurance from ground impact a fter re-entry a) According to ISO 27875, the expected number of casualties is estimated and limited, and ground pollution is avoided b) I f there is significant risk on the ground, a controlled re-entry is planned Such a plan includes the design o f a re-entry trajectory with control manoeuvers, error analysis, prediction o f the footprint o f surviving objects, etc Controlled re-entry requires a propulsion subsystem satis fying such objectives, su fficient propellant, and specific designs for avionics (designing for radiation hardness, etc.) These factors can require additional constraints for mass allocation (See ISO 27875) Other ground support systems are required, including ground tracking and control systems © ISO 2017 – All rights reserved 21 ISO/TR 20590:2017(E) 6.7 Production phase (phase D) 6.7.1 Work in phase D There are no specific debris-related requirements for manu facturing and verification/validation as long as the production procedures are properly controlled under the reliability and QA program The design and production procedures are qualified at the end o f this phase (See 6.7.2) Q u a l i f i c a t i o n r e v i e w In the qualification process, the final design and manu facturing procedures are verified through testing and design evaluation or demonstration The following items are reviewed at the QR: (1) List of parts that are designed to separate or be released; (2) List o f sources o f break-up energy; (3) A monitoring system for detecting critical mal functions that may cause break-up as far as technically feasible; (4) A disposal operation plan and data to be transferred to the operation phase; (5) Ground casualty expectations i f the orbital stages are disposed o f by orbit decay; (6) I f controlled re-entry is planned, review o f the operation plan; and (7) Plan for noti fying air tra ffic and maritime tra ffic authorities, in the case o f controlled re-entry 6.7.3 Launch service A fter qualification, the launch vehicles are applied to routine service For each launch mission, corresponding to launch mission requirements, mission analysis will be done, system configuration will be defined, the hardware will be validated, and served to launch operation at the launch site 6.8 Utilization phase (phase E) [In formation 1]: 1: Li ft-o ff time is typically coordinated to ensure that orbital stages, payloads, and other released objects from the orbital stages not put manned or man-able systems at risk [Information 2]: Debris mitigation measures are conducted according to the programmed sequence of events 6.9 Disposal Phase (phase F) Disposal actions are automatically conducted as follows: (1) At the end o f operation, the planned disposal manoeuvers defined in the SDMP are conducted I f a controlled re-entry is planned, it is most likely conducted with ground support [In formation 1]: Notification for controlled re-entry is given to the relevant nations, air tra ffic authorities, and maritime authorities (2) A fter completion o f disposal manoeuvers, residual energy (propellant, high pressure fluids, etc.) is removed (according to ISO 16127 until ISO 20893 is published) unless mechanical strength to assure that a break-up will not occur until the residual fluids are depressurized to a sa fe level [In formation 2]: I f there is potential risk that orbital stages can have inter ference with payloads by the venting force, the following item is considered: 22 © ISO 2017 – All rights reserved ISO/TR 20590:2017(E) For e xample, when venti ng o f re s idua l flu id s i s conduc te d , the e ffe c ts o f o ther device s (a nten na s , e tc ) , wh ich are e xp o s e d to the venti ng s tre am s , i s as s e s s e d to en s u re th at they no t c au s e unde s i rab le disturbances to the orbital stage System-level considerations 7.1 System design O nce the ma xi mu m ma s s o f p aylo ad s a re defi ne d a long thei r i nj e c tion orbit, ge o de tic cond ition s o f lau nch i ng s ite s a nd tracki ng s tation s a re identi fie d, a nd o ther cond ition s are defi ne d, the s ys tem concep t o f the lau nch veh icle i s s tud ie d T hen the “debri s m itigation de s ign ph i lo s ophy” e ffe c ts on s ys tem concep t a re e xam i ne d , s uch as; (1) C on s titution o f s tage s i s defi ne d to m i ni m i z e i nter ference with pro te c te d orbita l region s , grou nd c a s ua ltie s , prob abi l ity o f bre a k-up s , e tc O rbita l s tage s a re given fu nc tion s for d i s p o s a l mano euvers or control le d re - entr y, i f re qu i re d, for (2 ) missions that require such actions (3 ) S ol id reaching GEO Otherwise, the propellant is altered so that it does not generate slag or change the nozzle design so that it does not have submerged nozzles in upp er s tage s (4) O rbita l s tage s , who s e re - entr y z ard s no t comply with re s tric tion s , are given func tion s for propu l s ion s ys tem s , wh ich generate s lag , are no t re com mende d for use control le d re - entr y 7.2 Mission analysis for each launch mission launch m i s s ion, m i s s ion a na lys i s , wh ich i nclude s the fol lowi ng For e ach (1) Re - fi rmation o f phys ic a l charac teri s tic s o f p aylo ad s a nd thei r i nj e c tion orbits; conducted and reviewed before the pre-shipment review debri s relate d item s , is s uch as (2) Disposal planning; (3 ) D evelopment of fl ight pro fi le and s e quence of events (debri s m itigation me as u re s , tu rn i ng o ff the com mand de s tr uc t re ceivers; p aylo ad s ep a ration col l i s ion avoid ance; orbit ch ange ma no euver for d i s p o s a l; venti ng re s idua l fluid s; and control le d re - entr y, i f plan ne d ) ; and for (4) P rop el l ant a l lo c ation, i nclud i ng s u mp tion Subsystem / Component design and operation 8.1 d i s p o s a l m ano euver or control le d re - entr y General 8.1.1 Scope D u ri ng the de s ign rel ate d ph as e s (Pha s e s B, C, a nd D) , the re qu i rements defi ne d in C lau s e of ISO 24113 and other related standards are converted to design requirements and allocated to the de s ign s p e ci fic ation s for s ys tem, s ub s ys tem s , or comp onents T ho s e a l lo c ate d s p e c i fic ation s s upp or t engi ne ers engage d i n e ach s ub - s ys tem de s ign T he fol lowi ng (1) P ropu l s ion s ub s ys tem; (2 ) Gu idance and C ontrol s ub s ys tem; (3 ) E le c tric p ower- s upply s ub s ys tem; s ub s ys tem s a re mentione d i n th i s clau s e: © ISO 2017 – All rights reserved 23 ISO/TR 20590:2017(E) (4) C om mu n ic ation s ub s ys tem; (5 ) Str uc tu re s ub s ys tem; and (6) Ra nge s a fe ty s ub s ys tem (the s ame as the S el f- de s tr uc t s ub s ys tem) 8.1.2 Debris-mitigation measures and subsystem-level actions for realizing them Wh i le C lau s e o f I S O 41 de tai le d a l lo c ation o f i ntro duce d s ys tem-level de s ign concep ts , th i s clau s e pre s ents a more fu nc tion s and p er formance for e ach s ub s ys tem Table shows the relationships b e twe en the re qu i rements i n the I S O Sta ndard s and the re com mende d ac tion s for e ach s ub s ys tem Table — Debris-related technology and design of affected subsystem Name of debris-related technology Subsystem Propulsion Releasing of parts, slags, etc (a) Fasteners, clamp bands, etc (b) Slag from solid motors (c) Others (d) Support structures for mul- Guidance and Control Power supply Communication Structure - Range safety Yes Yes Yes ti-p aylo ad s l au nch i ng Prevention of fragmentation (a) Explosion of engines, propellant tanks, etc (b) Rupturing of high pressure vessels (c) Rupturing of Batteries (d) Unintentional activation of self-destruct devices for range s a fe ty s ys tem Disposal from protected regions Gro u nd s a fe ty (a) Re - entr y co ntrol ( b) I mprovement o f dem i s abi l ity (c) Avoidance of toxic material 8.2 8.2.1 Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Propulsion subsystem Debris-related design This clause applies to the main (and Vernier) engines (motors), attitude control thrusters, ullage thrusters (or motors), etc The items to be considered are shown in Table 24 © ISO 2017 – All rights reserved ISO/TR 20590:2017(E) Table — Debris-related measures in the propulsion subsystem Mitigation measures Liquid engine, Yes Yes Yes Yes Yes Yes Yes Yes Refrain from releasing objects Break-up prevention Disposal maneuver Ground sa fety Re-entry control 8.2.2 8.2.2.1 Major components Propulsion subsystem Thrusters Propellant tank Pressure vessels Valve, piping Solid motor Yes Yes Yes Yes Yes Yes - Yes - Yes (slag) Yes - Considerations for propulsion subsystems Refrain from releasing objects To refrain from releasing objects, the following items are considered, per ISO 24113: (1) In the case of solid motors, igniters and nozzle closures should be designed to not be released whenever possible, especially when they remain in orbit for a long time Solid motors, which contain metal and have submerged nozzles, tend to generate and exhaust slag They are not recommended for use in GTO or near GEO and should be avoided in LEO as much as possible (2) Auxiliary propulsion systems (ullage motors, retro motors, etc.) should not be separated, especially when they are injected into a long-lived orbit 8.2.2.2 Break-up prevention ISO 24113 requires the probability o f fragmentation during operation to be 0,001 or smaller except for such external factors as collision with debris The following are typical modes o f fragmentation relating to the propulsion subsystem: (1) Failures of engine or thrusters (failures of combustion related elements, turbo-pumps, turbines, heaters of thrusters, etc.) ; (2) Explosion caused by a mixture o f the homogeneous set o f fuel and oxidizer (As a typical example, a propellant tank design combining the fuel and oxygen tanks, separating them only by a common bulkhead, has caused many explosions, which are probably due to a de fect o f the bulkhead, which allowed the mixture of propellants); (3) Rupture o f highly pressurized tanks or vessels caused by de fects o f tank structure, failures o f regulators, valves, etc.; (4) Certain types o f gas jet thrusters can cause fragmentation due to cold-start induced by the failure o f the heater for the catalyst bed; A fter the EOM (injection o f payloads), energy sources o f break-up as the forms o f residual propellants and high-pressure gasses are vented or relieved, according to ISO 24113, 6.2, and ISO 16127 As addressed in 8.2.3.1 , the function and performance for venting and relieving residual fluids will be accomplished by coordinated work among related components, such as engines, tanks, pressure vessels, valves, piping, etc [In formation]: Complete depletion o f fluids is sometimes impossible in complicated propulsion systems ISO 16127, (5.3.2.1) shows the tailoring guidance for such cases © ISO 2017 – All rights reserved 25 ISO/TR 20590:2017(E) 8.2.2.3 Disposal maneuver In the case that disposal manoeuvres need stronger forces than can be obtained by passivation, re-start unctions o f the main engines or auxiliary propulsion systems, including independent devices attached specifically for such purposes, will be needed f The following characteristics are designed to comply with disposal manoeuver requirements: (1) Re-start functions o f the main engines or auxiliary propulsion systems, which are available a fter payload separation is designed; (2) Mission is designed to keep a su fficient amount o f propellant for disposal manoeuvres; (3) Tanks are designed to allow a sa fe and reliable re-start function o f main engines or auxiliary propulsion systems; and (4) Electric power subsystem and other subsystems support disposal manoeuvres 8.2.2.4 Ground safety and re-entry control Propulsion subsystems have several elements that survive re-entry, including major components o f liquid engines, propellant tanks made of stainless steel or titanium, pressure vessels made of titanium, large valves, motor cases, and nozzles of solid motors Design efforts are applied to minimizing objects that survive re-entry, but i f the total number o f casualties still cannot be made smaller than the requirement, a controlled re-entry is planned When a controlled re-entry is planned: (1) The propulsion system used for the final burn is designed to have enough thrust to provide enough delta velocity within a short period (2) In the event that controlled re-entry takes an extended amount o f operation time, longer than a simple disposal operation, radiation hardness design is applied for electronic devices and, more generally, for the avionics 8.2.3 Considerations for component design 8.2.3.1 8.2.3.1.1 Liquid propulsion systems Main liquid engine Engine reliability is a dominant factor in limiting the probability o f break-up to be lower than 0,001 as required by ISO 24113 As already mentioned in 5.7, it is important to ensure su fficient reliability and quality In ISO 16127, 5.1 contains the requirements for reliability and quality control to prevent failures that could lead to a break-up event [In formation]: When the probability o f break-up for complicated systems, like a large engine system, cannot be identified independently by separating it from other failures, ISO 16127, which is applied to the S/C, says “Where the break-up event is at system level, i.e., the break-up is a symptom o f one or more failures at system level, the break-up probability should be reviewed indirectly by its system reliability” in sub-Clause A.3 o f Annex-A To conduct disposal manoeuvres, it is desirable to have an engine re-start function Otherwise, auxiliary propulsion systems have the function o f supporting disposal manoeuvres, as low thrust engines described hereafter 8.2.3.1.2 e Gas jet thrust rs (and other low thrust engines or motors) Low thrust engines or motors can be designed for various purposes including attitude and trajectory control, acceleration for propellant settling before re-start, retro thrust to avoid collision, etc 26 © ISO 2017 – All rights reserved ISO/TR 20590:2017(E) [In formation]: Certain types o f gas jet thrusters can cause fragmentation when they are forced to start in cold start conditions due to the failure o f the heater for the catalyst bed Such types o f thrusters are only used i f it has been confirmed that their design precludes such a failure mode or i f by FDIR techniques are employed to avoid the cold starts 8.2.3.1.3 Design of propellant tanks Design of propellant tanks takes into consideration the following debris mitigation aspects: (1) Tank volume can be defined considering the propellant consumption for disposal manoeuvres and controlled re-entry, i f required (2) For ground sa fety from the tanks surviving re-entry, it is desirable to select materials which likely demise during re-entry Large main tanks made o f stainless steel have been found on Earth without melting, and small tanks, motor cases, and pressure vessels (even smaller than m in diameter) made of titanium have also been found on Earth Therefore, it is desirable to replace large tanks with aluminium tanks (as an example), and small tanks could be replaced by an aluminium skin overwrapped with composite materials or other materials that are easy to demise (3) To prevent explosions caused by mixing o f propellants, particularly in the case o f auto-ignition o f a two-liquid type propulsion system, care is taken so that tank arrangement prevents mixture o f liquids Moreover, common bulkhead tanks are avoided if not reliable and robust [Information 1]: If the design of a small tank does not include a venting mechanism (in the case of small tanks with bladders, etc.), a su fficient sa fety margin is provided (as per ISO 16127, 5.3.2) [In formation 2]: Tanks with a common bulkhead for a set o f homogeneous propellants can be risky because: a) Impact o f tiny debris can penetrate the tank skin and common bulkhead b) Unbalance of pressure between outer and inner tanks can defect the common bulkhead c) Aging and erosion o f the common bulkhead by one o f the propellants can induce mixture o f propellants [Information 3]:: In designing a venting mechanism, the following items are taken into consideration: a) When venting residual liquid propellants from tanks, the gradient of decreasing pressure takes into account the vapour pressure inside the tanks so as not to cause boiling o f liquid propellant, followed by rupture b) When venting liquid at a certain pressure drop, adiabatic expansion can cause freezing around the venting lines The venting line is designed and operated so as not to cause stack o f the venting flow (4) There was a case of rupture of a main tank after the end of operation, which was assumed to be caused by pressure increase due to the evaporation o f residual cryogenic propellant Tanks are equipped with a pressure relief mechanism and venting of residual propellant is conducted at the end of operations 8.2.3.1.4 Design of pressure vessels I f the orbital stage stays in orbit for a long period o f time (longer than a few years, for example), high pressure vessels (and high pressure propellant tanks) are designed either to be able to relieve pressure a fter the end o f operations, or to have sa fety margins that not allow rupture until the bleed valve attached to the pressure regulators reduces the inner pressure low enough I f the pressure vessels are made o f titanium, they can survive re-entry © ISO 2017 – All rights reserved 27 ISO/TR 20590:2017(E) 8.2.3.1.5 Design of valves and piping In design of valves and piping, the following points are considered: (1) It is desirable to have a mechanism to vent and minimize residual propellants after the end of operations S o me pro p el l a nt c a n b e a l lowe d to b e come trapp e d i n l i ne s a s lo ng a s the a mou nt i s i n s u ffic ient to NO TE c au s e a b re a k- up b y i gn ition or pre s s u re i nc re a s e (2) The failure rate of valves and pressure regulators, which can induce fragmentation of tanks or ve s s el s , i s control le d s o that the prob abi l ity o f bre a k-up i s le s s th an , 01 for the to ta l s ys tem (3) Venting lines are designed to prevent blockage from freezing propellants (ISO 16127, 5.3.2) [I n formation] : Venti ng or rel ievi ng i s no t me ant to p o s e advers e e ffe c ts on p aylo ad s or orbita l s tage s 8.2.3.1.6 Design of engine control avionics I f a control le d re - entr y i s pla nne d, the rad iation hard ne s s de s ign i s s idere d 8.2.3.2 Solid motors Solid motors whose propellants contain aluminium and which are equipped with submerged nozzles can generate and inject slag while in orbit ISO 24113 does not recommend the use of such motors for GTO or GES direct-injection missions to avoid contamination of the GEO protected region ISO 24113 a l s o encou rage s the development o f te ch nolo g y that avoid s the generation o f slag for LE O m i s s ion s [Information]: Solid rocket motor propellant ingot defects can cause break-ups Non-destructive i n s p e c tion o f the i ngo t o f s ol id mo tors c an b e u s e fu l to fi rm whe ther they cou ld c au s e a bre a k-up T here a re cer tai n typ e s o f ign iters that are ej e c te d a fter ign ition Such ign iters c an no t b e u s e d at h igh a ltitude s where they have long orbita l l i fe ti me s (over ye ars) No z z le clo s ure s cou ld a l s o no t b e ejected at high altitudes to remain in orbit for a long time period 8.3 Guidance and control subsystem 8.3.1 Debris-related designs T he me a s u re s ta ken i nto s ideration for th i s s ub s ys tem a re s hown i n Table Table — Debris-related measures in the Guidance and Control subsystem Major components Mitigation measures Disposal maneuver Re - entr y control 8.3.2 8.3.2.1 Guidance & Control Yes (Normal function) Yes Attitude monitoring sensors, etc Other electronic circuit - - Considerations for the guidance and control subsystem Disposal manoeuvres To conduc t d i s p o s a l mano euvers with the propu l s ion s ub s ys tem, the gu ida nce a nd control s ub s ys tem supports the determination of orbit and attitude, controls the disposal manoeuver thrust vector, and f f mission sequence of the launch program conduc ts the mano euver its el Us ua l ly tho s e ac tivitie s wi l l b e conduc te d accord i ng to a p a r t o 28 the © ISO 2017 – All rights reserved ISO/TR 20590:2017(E) 8.3.2.2 Controlled re-entry I n the c as e where a control le d re - entr y i s pla n ne d, the gu ida nce and control s ys tem i s re qu i re d to p er form the de term i nation o f p o s ition, velo city, and attitude o f the veh icle b o dy with h igh pre ci s ion u nti l it re ache s the p oi nt o f mano euvre s T he grou nd b a s e d ngi ng s ys tem or data from o ther op erati ng S/C c an s upp or t the gu ida nce and control s ys tem C ontrol le d re - entr y c a n re qu i re a longer duration o f op eration ti me 8.4 Electric power-supply subsystem 8.4.1 Debris related design T he item s ta ken i nto s ideration for the p ower- s upply s ub s ys tem a re s hown i n Table 10: Table 10 — Debris-related measures in the power-supply subsystem Battery Yes Yes (Normal function) Yes Yes Yes Yes Yes - Mitigation measures Break-up prevention Disposal manoeuver Grou nd s a fe ty Re - entr y control 8.4.2 Control/ distribution device - Considerations for power subsystems 8.4.2.1 T he Major components Power-supply subsystem Prevention of break-up b atter y i s the on ly s ource o f bre a k-up manufactured as described in 8.4.3.1 energ y i n th i s s ub s ys tem B atterie s a re de s igne d a nd n 8.4.2.2 Disposal manoeuver and controlled re-e try D i s p o s a l mano euvre s a nd control le d re - entr y a re conduc te d by a combi nation o f mo s t o f the propu l s ion, p ower, guidance and control, a nd com mu n ic ation s ub s ys tem s B atter y c ap acity i s de s igne d to s upp or t the whole duration of such an operation period 8.4.3 Consideration in component design 8.4.3.1 Design of batteries Si nce the b atterie s are the on ly p o tenti a l energ y s ource de s igne d and manu fac tu re d prop erly in all ele c tric a l for and bre a k-up s i n th i s s ub s ys tem, they are me chan ic a l increases of internal pressure or structural fractures never happen Si nce launch veh icle s typic a l ly no t have thei r own p ower generation as p e c ts fu nc tion s , so that abnorma l b atterie s a re de s igne d to h ave enough c ap acity (even i n wors t- c a s e cond ition s) to s upp or t d i s p o s a l mano euvre s and control le d re - entr y B atterie s tend to s u r vive re - entr y T hey a re a s s e s s e d i n the s u r vivabi l ity ana lys i s to c a lc u late E c © ISO 2017 – All rights reserved 29 ISO/TR 20590:2017(E) 8.4.3.2 Design of electronics I n the c a s e o f control le d re - entr y, avionics are e xp o s e d to the rad iation envi ron ment longer th an i n the s i mp le c a s e, wh ich term i nate s the m i s s ion at the s ep aration o f p aylo ad s Rad i ation hard ne s s de s ign i s s idere d 8.5 for c a s e s where control le d re - entr y i s a p o s s ibi l ity Communication subsystem 8.5.1 Debris-related designs T he com mun ic ation s ub s ys tem s i s ts o f the teleme tr y tra n s m itter, radar tran s p onder, and o ther com mun ication e qu ipment M e a s uri ng a nd data tran s m i s s ion e qu ipment i s i nclude d i n th i s c ategor y i n this document I tem s to b e s idere d for th i s s ub s ys tem are shown i n Table 11 Table 11 — Debris-related measures in the communication subsystem Mitigation measures Yes (Normal function) Yes Yes Disposal maneuver Grou nd s a fe ty Re - entr y co ntro l 8.5.2 Communication subsystem Yes Measuring systems Yes (Normal function) Yes (Normal function) Support for disposal manoeuver NO TE T here a re no s p e c i fic re qu i rements adde d to the nor m a l 8.5.2.2 fu nc tion s to s upp o r t d i s p o s a l m a no eu vers Supporting controlled re-entry For a control le d re - entr y, add itiona l (2 ) Tele-communication Design of communication subsystem 8.5.2.1 (1) Major components func tion s and p er formance c an b e re qu i re d as Si nce longer duration s o f op eration p erio d s are ne ce s s ar y for normal operation, radiation hardness design can be required I f the fu nc tion s fol lows: control le d re - entr y, add i ng to the are re qui re d to de term i ne the i n iti ation o f control le d re - entr y and mon itor the cond ition i n the re - enteri ng traj e c tor y, the me a s uri ng func tion i s de s igne d to che ck the he a lth o f the related functions when required (3) If the functions are required to receive a command from the ground for initiation or termination of re - entr y, the com ma nd l i ne i s de s igne d to remai n ac tive and re ceive th i s com mand 8.5.3 8.5.3.1 NO TE Considerations for component design Measuring instruments To fi r m b a s ic fu nc tion a nd p er for m a nce a nd to m a i nta i n fl ight s a fe ty, th i s s ub s ys tem me a s u re s and transfers the basic parameters and major event signals to the ground control centre It also includes the p a me ters a nd e vent s ign a l s re qu i re d to fi r m the co mp le tion o f d i s p o s a l m a no euvers a nd the venti ng o f the re s idu a l flu id , i f p o s s ib le I f a control le d re - entr y i s pla nne d, th i s s ub s ys tem i s u s e d to s upp or t de term i nation to pro ce e d to a control le d re - entr y mano euver or c ancel it, i f de s igne d to s o 30 © ISO 2017 – All rights reserved ISO/TR 20590:2017(E) 8.5.3.2 Command link I f a com ma nd l i n k i s re qui re d 8.6 for control le d re - entr y, the l i n k i s ma i ntai ne d duri ng re - entr y op eration s Structure subsystem 8.6.1 Design measures The following items are considered: (1) Refrain from releasing objects; and Sur vivabi l ity duri ng re - entr y to en s ure grou nd s a fe ty (2 ) 8.6.2 8.6.2.1 T he Practices for structure subsystem Intentional release of parts fol lowi ng obj e c ts c an no t b e rele as e d c an b e u s e d to contai n a l l p a r ts and from the launch veh icle S ome typ e o f c ap tu ri ng me cha n i s m fragments , a nd a yo -yo de - s pi n ner cou ld b e ch ange d to a no ther typ e o f propu l s ion device (1) C lamp -b a nd s fas ten i ng the p aylo ad to the orbita l s tage; (2) Fasteners for launch vehicle interstages; (3) Separation bolts, wire-cutters, etc.; and (4) Yo -yo de - s pi n ner [I n formation 1] : I n the ca s e o f lau nch i ng o f mu ltip le p aylo ad s , one or mu ltiple s tr uc tu l elements that s upp or t p aylo ad s ca n b e rele as e d H i s toric a l ly, the s truc tu l elements h ave b e en s ep a rate d i nto a s ma l l numb er o f fragments and rele as e d i nto orbit, but they a re a l lowe d i nternationa l ly i f thei r orbita l l i fe ti me i s s hor ter th an ye ars [I n formation ] : Sub orbita l obj e c ts (e g p aylo ad from an orbital debris standpoint 8.6.2.2 To en s u re grou nd s a fe ty a fter re - entr y, 8.6.3.1 rele as e d du ri ng e a rly a s cent are no t o f concern Assurance of ground safety te ch n ic a l ly p o s s ible, s ideri ng 8.6.3 fa i ri ngs) 5.5.3.2 s tr uc tu l elements “H a z ard ana lys i s ” a nd are de s igne d to b e dem i s e d a s 5.5.3.3 “Design measures.” fa r as Considerations for component design Support truss, gimbal rod, and other structural elements To en s u re grou nd s a fe ty a fter re - entr y, the s upp or t tr u s s , gi mb a l ro d , and o ther s truc tu l elements are designed considering 5.5.3.2 8.6.3.2 “H a z a rd ana lys i s ” a nd 5.5.3.3 “Design measures.” Dummy mass S o - c a l le d du m my ma s s e s , typic a l ly i ntro duce d on maiden fl ights or app l ie d to ma i ntai n ma s s b a lance when a p aylo ad c a ncel s its p ar ticip ation i n the fl ight, a re de s igne d s ideri ng and 5.3.4 “Design measures.” © ISO 2017 – All rights reserved 5.5.3.2 “H a z ard ana lys i s ” 31 ISO/TR 20590:2017(E) 8.7 Range safety subsystem (Self-destruct subsystem) 8.7.1 Debris-related designs In this clause, the following measures are described: (1) P revention o f acc identa l e xplo s ion b y m i s s- com mand; and (2) Prevention of accidental explosion due to solar heating in orbit after operation 8.7.2 Consideration for command destruction subsystem T he com mand re ceiver i s tu rne d o ff a fter p a s s i ng th rough the nge s a fe ty are a to prevent e xplo s ion s cau s e d b y accidenta l or s pu riou s (RF I : Rad io Fre quenc y I nter ference) m i s s - com ma nd 8.7.3 It is Considerations for component design s ome ti me s ne ce s s ar y to attach a therma l s h ield to the s el f- de s tr uc t s ys tem to mai ntai n temperature within operational bounds (cook-off temperature) and prevent accidental destruction 32 its © ISO 2017 – All rights reserved ISO/TR 20590:2017(E) Bibliography [1] [2] [3] [4] [5] [6] ISO 24113:2011, Space systems — Space debris mitigation requirements ISO 27852:2011, Space systems — Estimation of orbit lifetime ISO 16699:2015, Space systems — Disposal of orbital launch stages ISO 20893, Space systems — Prevention of break-up of orbital launch stages ISO 16127:2014, Space systems — Prevention of break-up of unmanned spacecraft ISO 16126, Space systems — Assessment of survivability of unmanned spacecraft against space [7] [8] [9] ISO 16164:2015, Space systems — Disposal of satellites operating in or crossing Low Earth Orbit ISO 26872:2010, Space systems — Disposal of satellites operating at geosynchronous altitude ISO 27875:2010, Space systems — Re-entry risk management for unmanned spacecraft and launch debris and meteoroid impacts to ensure successful post-mission disposal vehicle orbital stages [10] ISO 14300-1:2011, Space systems — Programme management — Part 1: Structuring of a project [11] ISO 14300-2:2011, Space systems — Programme management — Part 2: Product assurance [12] ISO 14623:2003, Space systems - Pressure vessels and pressurized structures — Design and operation [13] ISO 27025:2010, Space systems — Programme management — Quality assurance requirements [14] ISO 10795:2011, Space systems — Programme management and quality — Vocabulary [15] ISO/TR 16158:2013, Space systems — Avoiding collisions with orbiting objects [16] Space Debris Mitigation Guidelines of the Scientific and Technical Subcommittee of the Committee [17] on the Peaceful Uses of Outer Space, Annex IV o f A/AC.105/890, March 2007, endorsed by the United Nations General Assembly under Resolution A/RES/62/217 IADC Space Debris Mitigation Guidelines, IADC-02-01, Revision 1, September 2007, available at http://www.iadc-online org/index.cgi?item= docs _pub [18] Support Document to the IADC Space Debris Mitigation Guidelines, IADC-04-06, Issue 1, October 2004, available at http://www.iadc-online org/index.cgi?item= docs _pub © ISO 2017 – All rights reserved 33 ISO/TR 20590:2017(E) I C S 49 40 Price based on 3 pages © ISO 2017 – All rights reserved