Overview
ISO 17540:2025 - Space systems - Liquid rocket engines and test stands - Vocabulary specifies standardized terms and definitions used in the design, testing, reliability analysis and quality control of liquid rocket engines (LRE) and associated test stands. This second edition updates and consolidates terminology for engineers, test engineers, quality managers and authors of technical documentation to ensure consistent communication across design, test, operation and regulatory activities in the space sector.
Key topics and technical scope
The standard is a vocabulary reference; it does not prescribe test methods or performance limits but defines terms used across technical work. Major topical groups include:
- General definitions for rockets, liquid rocket engines, liquid-fuelled thrusters and liquid rocket propulsion systems (LRPS, CLRPS).
- Major engine units: thrust chamber, turbopump (TPU), gas generator, booster turbopump, etc.
- Cycle and feed types: closed-cycle vs open-cycle engines, pressure-fed vs pump-fed systems.
- Engine classifications by reusability, firing capability and purpose (main engine, control engine, retrorocket, correction engine).
- Thruster types: catalytic, thermo-catalytic, electro-thermo-catalytic and variants.
- Performance and time characteristics: basic parameters, operating life, operating modes and thruster performance metrics.
- Components and nozzle vocabulary: combustion chamber components, nozzle types, nozzle flows and operating modes.
- Turbopump and pump terminology: components, characteristics and performance descriptors.
- Engine control, steering and thermal protection vocabulary.
- Comprehensive test and reliability terminology: engine test types (by thermal load, site, purpose), test procedures and conditions, test results, defects, failure modes, reliability analysis and quality control terms.
- Test stand terminology: stand types, systems, devices, stand room and post-test processing systems.
Practical applications and users
ISO 17540:2025 is intended for:
- Rocket and spacecraft propulsion engineers preparing design documentation, specifications and interface control documents.
- Test engineers and test-stand operators developing test procedures and reporting test results.
- Reliability, safety and quality assurance teams conducting failure mode analysis, health monitoring and quality control.
- Standards bodies, regulators, contractors and academic authors who need consistent, cross-disciplinary vocabulary.
Practical uses include harmonizing technical documentation, improving clarity in procurement and contracts, standardizing lab/test-data reporting, and supporting training and knowledge transfer.
Related resources
- ISO Online Browsing Platform (for related ISO terminology)
- IEC Electropedia (for cross-referenced electrotechnical terms)
For implementation, consult your national standards body for access and permissions to the full ISO 17540:2025 text.
