This Standard contains provisions for the design of on-board functions for unmanned space segments in order to ensure that the space segment can be operated in-flight in any nominal or predefined contingency situation.

The requirements in this Standard are grouped in two clauses, containing general operability requirements and detailed operability requirements, respectively. The general operability requirements can be applied to all missions, whilst the detailed operability requirements are only applicable if the corresponding on-board function is implemented.

The operability of the space segment to meet mission-specific requirements is outside the scope of this standard.

To support the users of this Standard in tailoring the requirements to the needs of their particular mission, Annex B contains a table that indicates, for each requirement, the potential impact of its omission.

This standard may be tailored for the specific characteristics and constraints of a space project, in conformance with ECSS-S-ST-00.