What is the International Testing Standard "ASTM"?

Outgas Evaluation Criteria:
Ensuring Material Reliability

Steps for Material Selection Using ASTM Testing

Materials and components used in space equipment require high reliability in their quality to support mission success. Molecular contamination in vacuum environments, in particular, is an "invisible problem" that affects the performance of optical instruments and observation sensors, necessitating verification from the material selection stage. The standardized evaluation method for this is testing according to ASTM (American Society for Testing and Materials).
ASTM is a U.S. private standards organization that develops international standards used across all industrial sectors, not limited to space materials. These standards are also recommended for material evaluation by space agencies such as NASA and JAXA.

The three primary test standards relevant to space materials are listed below. Each differs in application, purpose, and measurement method, and they are used sequentially as needed.

【ASTM E595/E1559/E2900
Comparison Table】

Test Standard	Primary Purpose	Applicable Materials / Applications	Test Method	Test Conditions	Applicable Standard	European Equivalent Standard
ASTM E595	Basic material suitability evaluation (Outgas measurement)	Structural materials, thermal insulation, electronic components, adhesives, films, etc., for spacecraft	[High-Precision Balance] TML/CVCM^(*1) measured using a balance and cooling plate QCM is effective as a complementary method for understanding TML/CVCM behavior	125°C / 25°C Cooling / Vacuum 10⁻³ to 10⁻⁵ Torr / 24 Hours	NASA-STD-6016 / JERG-2-144-HB	ECSS-Q-ST-70-02C
ASTM E1559	Detailed analysis of outgas due to time and temperature changes	Optical systems, high-precision electronic equipment, precision instruments, and other diverse applications	【QCM】　Real-time analysis of outgas and condensation	+25 to +125°C / -183 to +25°C Cooling / vacuum / 24 to 48 Hours	NASA-STD-6016	ECSS-Q-ST-70-06C
ASTM E2900	Long-term operational suitability evaluation of materials (Confirmation of degassing completion)	Components for long-term use in probes, communication satellites, and space stations	【QCM】 Measures residual outgas to evaluate degassing completion	+125°C / -50 to +50°C Cooling / Vacuum 10⁻⁶ to 10⁻⁸ Torr / Several hundred hours	NASA-STD-6016	ECSS-Q-ST-70-05C

(＊1)：TML＝Total Mass Loss
CVCM＝Collected Volatile Condensable Material

Tests Supported by QCM：E1559／E2900

For materials manufacturers, meeting E595 is the primary requirement. However, when components are actually installed in space equipment, there is an increasing need to verify long-term behavior and complete outgas, as specified by standards like E1559 and E2900. NDK's QCM supports testing according to ASTM E1559 and E2900, preparing for this "next phase."

ASTM E1559

Continuous real-time monitoring of gas release rates over temperature changes and time.

For details, please refer to the presentation materials available at IEEE below.

Titles and Themes	Twin-CQCM and Twin-TQCM Sensors With Wide Operating Temperature Range for Outgassing and Atomic Oxygen Measurement
Paper Journal / Conference Presentations	IEEE Sensors Journal, vol. 21, no. 9, pp. 10530-10538, 2021.
Paper Authors	Yuta Tsuchiya(JAXA), Hiroyuki Kukita(NDK), Tsuyoshi Shiobara(JAXA), Kazuki Yukumatsu(JAXA), and Eiji Miyazaki(JAXA)

ASTM E2900

Confirmation of complete outgas was achieved through extended testing lasting from 48 hours to several hundred hours.
The following is an example of extended testing where O-rings were heated under vacuum to evaluate the convergence state of outgas.
Using QCM enables continuous monitoring of outgas behavior, visualizing the transition to the final stable state.

【 O-Ring Outgas Adhesion Characteristics 】

Measurement Conditions: 3 O-Ring Types (FKM/VMQ/NBR)
Temperature Conditions: Constant EmperatureMmaintained at 130°C
Measurement Duration: Maximum 4 Hours (Note: E2900 Typically Extends to Hundreds of Hours)

※The graph shown simulates a portion of the E2900 test conditions. The formal E2900 test involves evaluation over significantly longer durations.

ASTM E595

In the initial stages of outgas testing, ASTM E595 is often used as the "first hurdle" for material selection.
This test involves quantitative evaluation of TML and CVCM using a high-precision balance. QCM is an effective complementary method for understanding the TML/CVCM behavior required by ASTM E595.
*When formal submission values are required for E595 (e.g., NASA or ESA specifications), testing must be conducted by an accredited laboratory.