Overview
ISO 16378:2022 - Space systems - Measurements of thermo‑optical properties of thermal control materials - defines standardized methods for measuring the thermo‑optical properties (solar absorptance and infrared emittance) of materials used in spacecraft thermal control. The standard specifies multiple test methods, required sample configurations, instruments, calibration and reference material requirements, and guidance on limitations, biases and data quality to ensure reliable ground‑based material property data for thermal design and verification.
Key topics and requirements
- Measured properties
- Solar absorptance (αs, αp) - two approaches: spectrophotometer method (Annex A) and comparative test method (Annex B).
- Infrared emittance - hemispherical thermal method (εh‑t, Annex C) and normal emittance methods using an IR spectrometer (εn‑s, Annex D), ellipsoid collector optics (εn‑e, Annex E), and two rotating cavities (εn‑c, Annex F).
- Sample preparation and handling
- Defined sample properties, thickness and configuration, cleaning, handling, storage and identification requirements to reduce measurement variability.
- Facilities and equipment
- Environmental, cleanliness and equipment specifications for valid measurements.
- Calibration and reference materials
- Requirements for reference standards and working standards to achieve traceability and data comparability.
- Data quality and reporting
- Mandatory content for test reports (identification, measurement conditions, results), uncertainty evaluation, precision, and non‑conformance handling.
- Quality assurance and audit
- Procedures for calibration, traceability, uncertainty estimation and periodic audits/acceptance tests of measurement systems.
Applications and who uses it
- Who uses ISO 16378
- Spacecraft thermal engineers, materials scientists, test laboratories, quality assurance teams, suppliers of thermal control coatings and multi‑layer insulation (MLI), and certification bodies.
- Practical uses
- Material selection and qualification for spacecraft thermal control.
- Input properties for thermal models and on‑ground to on‑orbit performance comparisons.
- Process control and production quality assurance of thermal coatings and surface finishes.
- Establishing traceable datasets for beginning‑of‑life thermal performance assessments.
Related standards
- ISO 16378 complements other space and radiometric standards that cover terminology, blackbody radiation and uncertainty/traceability practices (see ISO Online Browsing Platform for linked references). For spectral and radiometric definitions refer to ISO 80000 series and ISO 9288 where applicable.
Keywords: ISO 16378:2022, thermo‑optical properties, thermal control materials, solar absorptance, infrared emittance, space systems, calibration, traceability, spectrophotometer, IR spectrometer.