The ECSS Standard on Space Segment Operability

Abstract

1. Abstract The ease of operation (i.e. the operability) of a spacecraft in orbit has an impact on total life cycle cost inasmuch as increased operability can increase development costs but certainly decreases operations costs. A new mission should therefore seriously consider the adoption of specific operability requirements for its on-board design by careful balancing costs, risks, and schedule impact for both the development phase and the operations phase. The European Cooperation for Space Standardization (ECSS) has decided to develop a standard on space segment operability for unmanned missions [Ref.1] whose key objectives are: • to ensure that a spacecraft can be operated in a safe, efficient and cost-effective manner; • to facilitate the tasks of preparation for, execution and evaluation of, spacecraft check-out and mission operations activities; • to assist the tasks of spacecraft prime contractors when preparing a proposal in answer to a request for proposal (RFP). The requirements in the standard are derived from experience gained over more than 30 years from the in-orbit operation of European spacecraft. The challenge in drafting operability requirements that will be useful for future missions is to generalise past experience in such a way that it is applicable to a wide range of different mission classes whilst remaining relevant to present and emerging space technologies. This paper identifies the structure of ECSS and the context of the standard within the overall ECSS standards tree. It then presents the structure and content of the standard, discusses some of the particular problems encountered during drafting and identifies the schedule for publication of the standard.