ISO 16781-2021 PDF

Full title and description

Space systems — Simulation requirements for control system (ISO 16781:2021). This international standard defines minimum, generic requirements and guidance for the simulation of flight control systems (guidance, navigation and control — GNC) used on space systems such as launch vehicles, satellites and spacecraft, covering objectives, architecture, procedures and documentation across development phases.

Abstract

ISO 16781:2021 establishes requirements for the planning, design and execution of simulations of space flight control systems. It describes simulation objectives, recommended architecture, procedure elements and documentation, and identifies what should be simulated during four development phases: conceptual design, detailed design, prototype and integrated system. The standard is intentionally generic so it can be applied across different mission types and simulation approaches; implementation details are left to project-specific standards, requirements and handbooks.

General information

• Status: Published
• Publication date: 15 March 2021
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 49.140 — Space systems and operations
• Edition / version: Edition 2 (2021)
• Number of pages: 22

Scope

Specifies a minimum set of requirements for simulation of the flight control system (GNC) of space systems, and provides guidance for what to simulate at each phase of control-system development: conceptual design, detailed design, prototype and integrated system. The standard covers simulation objectives, architecture and procedures, expected simulation artefacts and documentation practices. It applies to a broad range of simulation types (software-in-the-loop, hardware-in-the-loop, real-time and offline) and to different classes of space vehicles; however, detailed implementation, fidelity targets and project-specific test programs are defined outside this standard.

Key topics and requirements

• Definition of simulation objectives aligned to development phase (concept, detailed, prototype, integrated system).
• Recommended simulation architecture and separation of models, interfaces and facilities.
• Requirements for modelling of vehicle dynamics, sensors, actuators, environment and failure modes.
• Guidance on fidelity levels, model verification and simulator validation commensurate with the test purpose.
• Procedures for scenario definition, input data management and repeatability of runs.
• Documentation and configuration control of models, scenarios, interfaces and results.
• Support for hardware-in-the-loop (HIL), software-in-the-loop (SIL), processor-in-the-loop (PIL) and end-to-end testing approaches.
• Requirements for test reporting, traceability to requirements and use of simulation in verification and validation.

Typical use and users

Used by spacecraft and launch vehicle system engineers, GNC/AOCS designers, simulation and test laboratories, system integrators, prime contractors and verification teams. Typical applications include early concept trade studies, control-law design and tuning, fault scenario testing, hardware-in-the-loop verification, operations rehearsal and verification/validation activities supporting qualification and acceptance.

Related standards

ISO 16781:2021 revises and replaces ISO 16781:2013. It is published under the work of ISO/TC 20/SC 14 (Space systems and operations) and is commonly used alongside project- and agency-level space standards and guidance for simulation and verification (for example ECSS simulation and verification documents and agency verification handbooks). Implementation-level simulation requirements are typically aligned with applicable ECSS documents, national space-agency standards and project-specific verification plans.

Keywords

simulation, space systems, flight control, GNC, guidance, navigation, control, simulator architecture, hardware-in-the-loop, model verification, validation, test procedures, configuration control, verification and validation

FAQ

Q: What is this standard?

A: ISO 16781:2021 is an international standard that specifies minimum, generic requirements and guidance for the simulation of space flight control systems (GNC) across development phases.

Q: What does it cover?

A: It covers simulation objectives, recommended architecture, procedures, model and interface expectations, documentation and configuration control, and guidance on what to simulate during conceptual design, detailed design, prototype and integrated-system phases.

Q: Who typically uses it?

A: Systems and control engineers, GNC developers, simulation facility managers, test and verification teams, spacecraft and launch vehicle integrators, and contractors involved in control-system design and validation.

Q: Is it current or superseded?

A: ISO 16781:2021 is the current published edition (published 15 March 2021) and supersedes ISO 16781:2013. As with other ISO standards, it is subject to periodic review.

Q: Is it part of a series?

A: It is part of the family of ISO standards for space systems (work under ISO/TC 20/SC 14) but is a standalone document focused on simulation requirements for control systems; related simulation and verification guidance exist in ECSS and agency-specific standards.

Q: What are the key keywords?

A: simulation, flight control, GNC, guidance, navigation, control, hardware-in-the-loop, model validation, simulator architecture, verification.