ASTM E1559 Contamination Outgassing Characteristics of Spacecraft Materials

Get Certified ASTM E1559 Testing for Reliable Spacecraft Material Qualification

Certification confirms that spacecraft materials meet the relevant ASTM E1559 requirements for acceptable outgassing kinetics and deposition behavior in a vacuum environment. ASTM E1559 certified testing measures a material’s molecular contamination potential before mission engineers accept it for use near optical or sensor-critical spacecraft components. Testing and certification verify compliance with ASTM E1559 requirements and minimize mission failures due to contamination. 

The main objective of ASTM E1559 is to measure how quickly the materials given in spacecraft can outgas in a controlled vacuum environment. It is employed in industries for material selection, contamination control, and mission-critical optical and sensor protection. The scope of ASTM E1559 includes-

• Material: Organic, polymeric, and inorganic spacecraft materials such as potting compounds, foams, elastomers, films, adhesives, coatings, fabrics, and lubricants.
• Purpose: Quantification for evaluation of outgassing kinetics and molecular contamination.
• Property measured: Total mass flux, deposition rate, and collected volatile condensable material.
• Method: The test involves heating the specimen under vacuum in an effusion cell. Quartz crystal microbalances held at specified collector temperatures measure the deposited mass.
• Result: Mass flux and deposition rate are measured in nanograms per square centimeter.
• Test Limitations: It applies to specimen temperatures from 298 K to 398 K, and the test pressure is less than 7×10-3 Pa.
• Environmental conditions: Specimen temperature and collector temperature significantly affect deposition rate and contamination behavior.
• Applications: Satellite component qualification, optical and sensor contamination control, spacecraft material selection, mission reliability assurance.

What are the Uses of ASTM E1559 Testing?

ASTM E1559 testing helps evaluate the molecular contamination behavior of spacecraft materials in vacuum. Engineers then use the results to compare materials and to find out how well materials prevent contaminants from landing on sensitive spacecraft surfaces. This standard-

• Determines outgassing rates of spacecraft materials.
• Simulates vacuum exposure by using a controlled effusion cell system.
• Evaluates the deposition behavior on surfaces with different collector temperatures.
• Helps to support mathematical models for contaminant migration prediction.
• Helps to compare materials for spacecraft applications.
• Helps to keep optical lenses and sensors free from contamination.
• Supports the selection of materials for mission-critical parts of spacecraft. 

What Materials Can Be Tested Under ASTM E1559? 

ASTM E1559 is used to test the low outgassing properties of adhesives, coatings, polymers, lubricants and composites in spacecraft construction that meet stringent material requirements in vacuum and high radiation environments. A sample size, which is large enough to expose a representative surface area within the effusion cell, is selected by the analysts.

Why is ASTM E1559 Important? 

ASTM E1559 is important for ensuring that spacecraft and other systems function reliably and perform, providing a standardized method of assessment of material outgassing and preventing mission-critical failures. Mission engineers use these measured kinetics to protect optical lenses, sensors, and other contamination-sensitive equipment from performance degradation during a mission. 

ASTM E1559 Testing Process and Data Collection

Testing starts after the specimen is weighed and placed into the effusion cell, and the vacuum chamber is pumped to the desired pressure. The temperature control system then raises the temperature of the specimen to the desired temperature, while the chamber holds the vacuum conditions. The quartz crystal microbalances located at their assigned collector temperatures continuously measure the amount of mass deposited as the outgassing products move from the specimen. The data acquisition system records the deposition reading during the exposure period. Finally, the analyst analyzes the data recorded to determine the mass flux and deposition rate as a function of time and temperature. 

Common Challenges and Troubleshooting

The difficulties of testing are maintaining vacuum, detecting volatile substances, and guaranteeing substrate precision. Troubleshooting includes recalibrating pumps, cleaning the sample holders, and checking sensor alignment. It is crucial to ensure accurate results to the right standards. Laboratories overcome these issues by measuring the vacuums in the chambers, adjusting the temperature controls for the collectors, and conditioning the specimens prior to their testing under controlled storage conditions.

• The total mass flux and deposition rate are reported by the laboratory, both as a function of time and collector temperature.
• The technician documents the material condition tested, such as the type of specimen and the preconditioning history.
• The analyst takes measurements of the deposition data under the given vacuum and temperature conditions, and correlates the data with the material being tested and the material’s composition.
• The engineer considers factors such as specimen temperature, collector temperature, and exposure duration when interpreting outgassing results for mission applications.
• Engineers use the measured outgassing kinetics to support contamination modeling and material selection for spacecraft components. 

Link to ASTM E1559