Overview
ISO 14622:2025 - "Space systems - Structural design - Loads and induced environment" defines principles for identifying and quantifying the loads and induced environment that a space system and its components encounter over their service life. The second edition updates terminology, clarifies safety factors, and adds a bibliography. It covers deterministic sizing principles while accounting for probability, combined loads, life-cycle phases and resulting design/verification requirements.
Key topics and technical requirements
- Scope and terms: Clear definitions for limit load, ultimate load, yield load, static/transient/oscillating loads, MEOP (maximum expected operating pressure), proof pressure and service life.
- System inputs required: design trajectory, geometry, inertial data, aerodynamic and thermal properties, stiffness and modal characteristics, propulsion and control data, and service-life parameters.
- Excitation sources: external (atmospheric flow, wind, turbulence, solar/planetary radiation) and internal (propulsion, control actions, separation/jettison events, onboard mechanisms).
- Intensity selection rule: when statistical dispersion is known, excitation intensity shall be chosen so it is not exceeded with 99% probability at a 90% confidence level; otherwise use a rational estimate accounting for uncertainty.
- Loading conditions and combinations: identification of mechanical (static, dynamic, shock), pressure (including MEOP and proof pressure), and thermal loads and the procedures to combine them into design load cases.
- Safety factors and life-cycle design: use of safety factors to derive yield and ultimate loads (J_Y, J_U) and proof factors for pressure testing; consideration of the full service life (manufacture, transport, launch, on-orbit operations, re-entry, reuse).
Practical applications and users
ISO 14622:2025 is intended for professionals involved in spacecraft structural design and verification, including:
- Spacecraft and launch vehicle structural engineers
- Systems and mechanical analysts (thermal, modal, vibration)
- Test engineers defining proof tests and qualification campaigns
- Project managers and assurance/certification authorities assessing structural margins
- Suppliers of pressure vessels and deployable structures who must account for MEOP and proof factors
Practical uses include defining load envelopes for finite-element analysis, establishing acceptance/proof-test levels, deriving design load cases for manufacturing and test plans, and harmonizing safety-factor application across a mission life cycle.
Related standards
Keywords: space systems, structural design, loads, induced environment, safety factors, limit load, MEOP, proof pressure, service life, loading conditions.
