ECSS – A Single Set of European Space Standards

Werner Kriedte
European Space Research & Technology Centre (ESTEC), Noordwijk, The Netherlands

Table of Contents


The European Cooperation for Space Standardization (ECSS) is an initiative established to develop a coherent, single set of user-friendly standards for use in all European space activities. Until now there is no uniform system of space standards and requirements in Europe.

The paper describes the standardization policy, ECSS organization and human effort, gives a presentation of the documentation architecture with three branches (Project Management, Product Assurance and Engineering) and provides the status and the a summary of the present work-plan of ECSS.

1. Introduction

Until now there is no uniform system of space standards and requirements in Europe. Although the presently used standards and requirements are similar, the remaining differences result in higher costs, lower effectiveness and in a less competitive industry.

At the beginning of 1993 the European space community realized that a solution had to be found to overcome these problems, and expressed their will to develop a new coherent system of European space standards.

The European Cooperation for Space Standardization (ECSS) was started officially in the autumn 1993, when the partners signed the ECSS terms of reference (TOR), which defined the framework and basic rules of the system. At this point, the partners jointly undertook the development of the system, designed to meet the main objective of providing a single coherent set of standards for use in all European space activities and particularly projects. The European space industry was fully associated with ECSS from the outset.

2. ECSS-P-00 “Standardization Policy”

The first task of the ECSS was to draw up a policy document. A dedicated working group was set up in late 1993, leading to the publication of a document entitled “Standardization Policy” under the number ECSS-P-00. This document addresses the different aspects of the system, including scope, objectives, implementation, authority, organization and documentation.

ECSS policy dictates, that ECSS standards shall promote the continuous improvement of methods and techniques, and the avoidance of unnecessary work. Experience from past projects and other appropriate sources shall be systematically incorporated into the ECSS system. ECSS standards must satisfy all European and international clients, and shall encourage industrial efficiency and competitiveness by limiting the variety of products and processes.

The ECSS standards will only be made applicable to a project by contract or other legal document. The party imposing the use of a standard is responsible for monitoring and ensuring the correct use and application of that standard.

All users of ECSS standards are invited to inform the ECSS Secretariat about experience gained from the application of ECSS standards, so that inadequacies in the standards may be corrected.

All members shall promote the application of the standards by encouraging organisations that develop. manufacture or use items related to space missions to
use the ECSS standards.

Requirements and not Means

Existing standards like ESA’s PSS line of documents stated exact details of functions and its quality, together with the means required to produce the wanted products or services. The advantage was a uniform product or service, with the disadvantage that requirements from other customers were different and that the contractor’s usual practice was anyhow different. Furthermore it showed that progress in technology was not easily accommodated.

ECSS stated in its Policy Document that each individual requirement should concern the need to be fulfilled, rather than the means to be used to fulfil it. In ISO Directives, a similar guidance is proposed that, whenever possible, requirements shall be expressed in terms of performance rather than design or descriptive characteristics, leaving more freedom for technical developments.

No Duplication of Standards

ECSS standards shall be harmonised with international standards or working practices where these have been, or are in the course of being, generally adopted by the European space industry.

The preparation of ECSS standards should take into account valid sources of information and the opinions of all interested parties. These methods should ensure rapid availability of standards at a reasonable cost when they are needed.

ECSS intends, on the other hand, to achieve a formal status on a selected part of the ECSS standards (as appropriate) as European Standards (EN) by the European Committee for Standardization (CEN), and by so doing increasing the efficiency of the European space industry and strengthen its international competitiveness.

Different Levels of Standards

One of the key aspect of ECSS is the documentation architecture, which is designed to facilitate the organisation and retrieval of information within the ECSS standards system. The documentation is basically organized into three main branches: Management, Product Assurance and Engineering, and four hierarchical levels. As shown in figure 1, this architecture is defined to the detail level required to differentiate major functions, disciplines and activities. The scope, purpose and location of every ECSS standard must conform to this architecture. Any subordinate standards falling below those shown in figure 1, will be organized in a manner approved by the Technical Panel.

  • Level 0 (ECSS-P-00) – The document at Level 0 describes the policy and objectives of the ECSS system and its architecture together with the principle rule for the creation, validation and maintenance of documents.
  • Level 1 (ECSS-M-00, ECSS-Q-00, ECSS-E-00) -The documents at Level 1 describe the strategy in the specific domain. They give a global view of the requirements and outline the interfaces between the elements (and the documents) at Level 2.
  • Level 2 (ECSS-M-10, ECSS-Q-10 …) – The documents at Level 2 describe the required objectives and functions for all aspects in the individual domain (project organization, quality assurance, system engineering, etc.).
  • Level 3 – The documents at Level 3 describe methods, procedures and recommended tools to achieve the requirements of Level 2 documents. In addition they define the constraints and requirements for interfaces and performance of the specified product or activity. The Level 3 documents are guidelines and are allowed to be adapted to the projects’ needs.

3. Overall Presentation of M-xx/Q-xx/E-xx

Domain of Activities

The purpose of a space project [1] is to deliver to a customer (and subsequently support or operate if required) a system which includes one or more elements intended for operation in outer space. The activities carried out by the system supplier are conveniently and conventionally categorised into five domains:

  • project management, responsible for achievement of the totality of the project objectives, and specifically for organisation of the project, and its timely and cost-effective execution.
  • engineering, responsible for definition of the system, verification that the customer’s technical requirements are achieved, and compliance with the applicable project constraints.
  • production, responsible for manufacture, assembly and integration of the system, in accordance with the design defined by engineering
  • operations, responsible for exercising and supporting the system in order to achieve the customer’s objectives during the operational phases (note; operations may be carried out by the customer, by the supplier or a third party on the customer’s behalf, or by a combination of these)
  • product assurance, responsible for the implementation of the quality assurance element of the project and also for certain other specialist activities.

The boundaries between these activities are not always clearly defined; for example:

  • the engineering, production, operations and product assurance domains each include an element of management which overlaps with the project management domain proper
  • production and operations include preparatory and supportive engineering activities, which may also be considered as part of the engineering domain
  • product assurance includes reliability, availability, maintainability and safety activities, which form an essential part of the design process in the engineering domain.

Common Document Structure

To ensure that the style and presentation are identical for all ECSS standards, the ECSS Technical Panel agreed to apply ECSS-Procedure-13A “Rules for the drafting and presentation of ECSS Standards” to all documents. As far as possible and practical these rules are in conformity with the corresponding rules in CEN (from which they were derived), ISO and IEC.


Harmonization between the three branches of the ECSS system – Management, Product Assurance and Engineering – was initially the task of a coordination group consisting of the three convenors, the Secretariat and the Technical Panel Chairman. It decided on the location of the harmonized content: project criticality is defined in ECSS-M-00, product classes in ECSS-E-00 and lifecycle phases are in ECSS-M-30.

After the first review of Working Group drafts two special harmonization team were created:

  • the Risk Management harmonization team to define and harmonize all requirements relating to the issue of Risk Manag
  • the Engineering / Product Assurance harmonization team to allocate the requirements between ECSS-Q-20 “Quality Assurance” and relevant Engineering Standards.

The Technical Panel also decided to create another Harmonization Team to address project documents identified in ECSS Standards which might be defined as deliverable documents.


ECSS standards are publicly available documents agreed as a result of consultation with space agencies in Europe and with industry, and are designed to secure acceptance by users. However, the publication of a standard by ECSS does not automatically ensure its use. Application of the standard depends on the voluntary action of interested parties, and becomes binding if a party is contracted to work under its conditions.

The European Space Agency, on behalf of the participating members, holds the copyright for all ECSS documents. No ECSS document may be reproduced in any form without the express consent of ESA. However, this consent has been granted to organisations participating in ECSS for their own use and for their contractors or subcontractors.

4. ECSS-P-001 “Glossary of Terms”

To promote the coherence of the set of standards, a clear and unambiguous definition of terms and acronyms used in the standards is required. The ECSS Glossary of Terms, ECSS-P-001, is a common reference for the definition of terms and acronyms used in the ECSS Standards. The glossary supports the creation and maintenance of coherent standards by defining a minimal set of common terms and definitions for use in all the ECSS Standards. Subject-specific terms, which are used in only one standard, are defined in that document. Terms which are used in more than one ECSS Standard are defined in the Glossary of Terms.

5. ECSS Organisation and Human Effort


Participants in the ECSS include Participating Member Agencies and the European Space Agency (ESA), Industry and Associates.

Associates are those governmental and scientific organizations desiring a formal tie with the ECSS, through which they can observe the development process of technical documentation and contribute to the ECSS System.

Associates are encouraged to participate actively and directly in the document development process.

ECSS comprises four organizational entities (Fig. 2):

  • Steering Board, which primarily sets policy;
  • Technical Panel, for overall management of all processes;
  • Secretariat, dealing with the traditional administrative tasks;
  • Working Groups, developing draft standards.

Steering Board

Chairman: M. LeFèvre, ESA/ESTEC Noordwijk

The ultimate responsibility for ECSS resides with the Steering Board. The Steering Board is responsible for:

  • drawing up the main objectives and defining the overall strategy of the European standardization process;
  • formally approving all ECSS standards;
  • ensuring the assessment of the effectiveness of the utilisation of the common standards/requirements and taking action on problems encountered;
  • ensuring the application of the standards by ECSS members;

Technical Panel

Chairman: Y. El Gammal, CNES Paris

The Technical Panel is composed of one delegate from each Member Agency, as well as representatives of the European space industry and other associated groups as agreed by the Steering Board. The Steering Board may invite a representative of a standardization organisation as associate.

The Technical Panel is responsible for:

  • assisting the Steering Board by drafting on a yearly basis the overall working plan and priorities;
  • creating Working Groups as necessary and agreeing on the terms of reference;
  • deploying and integrating the resources provided for the formation of a Working Group in accordance with the rules for Working Groups;
  • settling technical disputes raised by Working Groups;
  • commenting, reviewing and discussing draft Working Group documents;
  • issuing a finalised Working Group draft document for approval by the Steering Board;

Working Groups

At its meeting on 12 July 1994, the ECSS Technical Panel formed three Working Groups and selected their convenors:

  • Management Standards Working Group – Acting Convenor: Mr. E. Woodcock, DRA Farnborough
  • Product Assurance Working Group – Convenor: Mr. J. Marcoux, ESA Toulouse
  • Engineering Standards Working Group – Convenor: Mr. J. Carter, Matra Marconi Space Vélizy

The tasks of these three Working Groups were to identify, prepare and propose all Level 1 and Level 2 documents. These groups should also harmonize the content and terminology of these documents amongst each other.

Today also Working Groups exist for:

  • ECSS-E-20 “Space Engineering – Electrical & Electronics” – Convenor: Mr. P. Perol, ESA/ESTEC Noordwijk
  • ECSS-E-30 “Space Engineering – Mechanical” – Convenor: Mr. M. Klein, ESA/ESTEC Noordwijk
  • ECSS-E-40 “Space Engineering – Software” – Convenor: Mr. U. Mortensen, ESA/ESTEC Noordwijk
  • ECSS-E-50 “Space Engineering – Communications” – Convenor: Mr. C. Monaco, Alenia Spazio
  • ECSS-E-70 “Space Engineering – Ground Systems” – Convenor: Mr. J-F Kaufeler, ESA/ESOC Darmstadt

Overall Participation

Invitations to participate in the Working Groups were distributed to all Technical Panel members. As a general rule, a maximum of two experts from each member was accepted.

More than 200 people were involved in the different drafting activities of ECSS, of which more than 60% of participants came from industry nominated by and Space Agencies.

Overall there was a positive spirit among participants, with the achievement of 23 documents drafted and reviewed in less than one year, a
nd waiting now for final agreement by the ECSS Steering Board.


The ECSS Secretariat, provided by the European Space Agency, carries out all general secretarial and administrative duties needed for the operation of the ECSS System. The duties of the ECSS Secretariat include:

  • supporting the Steering Board and the Technical Panel;
  • recording and circulating documents;
  • maintaining status lists for membership, ECSS standards and other documentation;
  • publishing and distributing ECSS standards;
  • maintaining the ECSS System configuration, which includes assigning document codes and controlling the numbering of all ECSS standards and other documents.


The activities undertaken within ECSS are carried out without any exchange of funds among the members. Expenses incurred as a result of participation in ECSS are borne by the party concerned.

6. ECSS Workshop Toulouse

The ECSS Workshop 6 – 7 December 1995 in Toulouse, attended by 166 participants from 15 different countries, was a great success. The Workshop gave executives and managers from European space agencies and European space industry the opportunity to review the progress achieved so far in drafting the first set of standards. In a survey, the participants stressed the following points.


After the ECSS Workshop the following further conclusions can be drawn:

  • A pilot project for initial use of the standards is urgently needed. This is the highest priority issue at present;
  • An ad-hoc group is needed to propose the way forward for the training and promotion of ECSS Standards;
  • ECSS is now visible to the European Union, and has received a public statement of support from Mr. Vardakas (Director DG III).
  • The European Commission is considering the possibility of providing financial support to ECSS for secretarial support, but not for the development of standards. This is supposed to be provided under the supervision of CEN, according to the rules of the commission.
  • A space policy is being prepared by the Commissioner, Mme. Cresson, for submission to the European Parliament. ECSS will be explicitly addressed in this policy paper;
  • Liaison with Russia, China and the United States must be addressed. Harmonisation with American standards could be particularly difficult due to differences in the direction of standardisation. The liaison with ISO is related to this issue. It may be possible to develop a high-level standard for space projects within ISO which would be common to ECSS and the Americans. ECSS could then proceed to define its more detailed standards at level 2 and level 3;
  • Tailoring must be further refined.

7. Work plan 1996

The ECSS Steering Board ratified on 17 November 1995 the ECSS Work Plan 1996. Work will continue to finish the remaining level 2 standards. Further work is foreseen by the Technical Panel to complete the 15 internal procedures (where only four have been released by the Technical Panel), and to update, as an outcome of the Operations Review, the ECSS Terms of Reference and the Policy Document ECSS-P-00. For the Level 3 documents, the following work is foreseen: Branch
Editing of existing Documents Drafting of new documents Drafting of Data Requirement Document (DRD) Management
0 5 10 Product Assurance 21 4 5 Engineering
0 6 0 Total
21 15 15

8. Status (1 March 1996)

Fig. 3 shows the interfaces ECSS has with its members and the international liaisons.

Participant Member Agencies

Although only a part of all ESA member agencies are represented in ECSS, all member states supported the initiative in the ESA Council Resolution3.


  • (Paris, France) representing European Industry

9. Conclusion

The European Cooperation for Space standardization (ECSS) initiative is a challenge for the European space community.

The ECSS initiative is not intended to be revolutionary but rather evolutionary. It aims to, insofar as possible, make maximum use of existing standards, adopt commonly used international standards, and ensure coordination and liaison with standardization organisations.

ECSS is designed to increase the efficiency of the European space industry and to strengthen its international competitiveness. ECSS is set up in a spirit of true cooperation between agencies and industry – achievement of consensus is the major goal and as a consequence participation of agencies and industry in Europe is essential.

It is vital that all customers are convinced that ECSS standards are of high quality, and that they will apply these standards.

Success will depend on a relatively fast implementation. To meet the stated policy of ECSS application within the time limit set by the ESA Council requires a concentrated effort by all parties. The three Working Groups already
enjoy extensive, competent and active participation by all participating member countries and the European space industry. This is a very encouraging sign and gives confidence that the basic framework of ECSS standards will become available for new space activities by the end of 1996.


[1] Draft ECSS-E-00A – Space Engineering – Policy and Principle