Validation of Organics for Advanced Stirling Convertor (ASC)

Abstract

Organic materials are an essential part of the Advanced Stirling Convertor (ASC) construction as adhesives, potting, wire insulation, lubrication coatings, bobbins, bumpers, insulators, thread lockers. Since a long lifetime of such convertors to be used in the Advanced Stirling Radioisotope Generator (ASRG), sometimes up to 17 years, is required in various space applications such as Mars rovers, deep space missions, and lunar surface power, performance, durability and reliability of those organics should be critically evaluated in every possible material-process-fabricationservice environment relations. The objective of this study was to evaluate, validate, and recommend organics for use in ASCs. Systematic and extensive evaluation methodologies were developed and conducted for various organic materials. The overall efforts dealing with organics materials for the last several years are summarized in the key areas, e.g., process-fabrication optimization, adhesive bonding integrity, outgassing, thermal stability, and durability

Supporting Technology at GRC to Mitigate Risk as Stirling Power Conversion Transitions to Flight

“…The ASC-E2 will have 11 types of organics with most residing in the area of the linear alternator. 17 Organics characteristics being evaluated at GRC include outgassing, magnet bond strength, thermal stability, long-term aging, and radiation tolerance. The epoxies are being evaluated through long-term aging tests at near-nominal operating conditions, and through shorter term accelerated aging tests.…”