{"copyright":{"thirdPartyPermissionsProduced":false,"disclosedToPublic":false,"containsIndication":false,"publisherPermissionOrRightsToDistribute":false,"belongsToUsGov":false,"determinationType":"GOV_PUBLIC_USE_PERMITTED","thirdPartyContentCondition":"NOT_SET","belongsToContractor":false,"disclosedInvention":false,"licenseType":"NO","submissionId":20220003097,"containsThirdPartyMaterial":false,"belongsToPublisher":false,"id":"b0d95e5aeffc4156a4102613cfe0307f","belongsToAuthors":false},"subjectCategories":["Spacecraft Design, Testing And Performance"],"keywords":["Thermal Control","Coolant","leak","ISS","QDs"],"exportControl":{"isExportControl":"NO","submissionId":20220003097,"ear":"NO","id":"f34b559e04454265b134199cba838e61","itar":"NO"},"distributionDate":"2022-07-10T05:00:00.0000000+00:00","fundingNumbers":[{"number":"401769.06.01.01.01","submissionId":20220003097,"id":"86444aba6e674f21a15345cddf802629","type":"WBS"}],"title":"Coolant Leak from ISS External Active Thermal Control System (EATCS) – An Examination of Most Probable ","stiType":"CONFERENCE_PAPER","distribution":"PUBLIC","submittedDate":"2022-02-24T16:19:42.9980690+00:00","authorAffiliations":[{"organizationId":"4c6a2b878d76521da887cdcb2564bf90","sequence":0,"submissionId":20220003097,"meta":{"author":{"orcidId":"","name":"Darnell T. Cowan"},"organization":{"name":"Johnson Space Center","location":"Houston, Texas, United States"}},"id":"47565ccf534643f3b7e389f76c68bee0","userType":"CIVIL","userId":"170bf92e9fd74cd69fbc4ef55fa7328c"},{"organizationId":"4c6a2b878d76521da887cdcb2564bf90","sequence":1,"submissionId":20220003097,"meta":{"author":{"orcidId":"","name":"Timothy A. Bond"},"organization":{"name":"Johnson Space Center","location":"Houston, Texas, United States"}},"id":"b834f1423660452ba725d7ce71ecc1ec","userType":"CIVIL","userId":"1ba1ed79956945eca06b7067a451831e"}],"stiTypeDetails":"Conference Paper","technicalReviewType":"SINGLE_EXPERT","modified":"2025-08-31T18:39:21.7150190+00:00","id":20220003097,"created":"2022-02-24T16:06:43.6026220+00:00","center":{"code":"JSC","name":"Johnson Space Center","id":"dd46994b91a94cb2a2722617cbbadc55"},"onlyAbstract":false,"sensitiveInformation":2,"abstract":"The Port (P1) and Starboard (S1) External Active Thermal Control Systems (EATCS) are\nsingle phase, mechanically pumped ammonia loops that operate independently to cool\nmajority of the hardware and payloads onboard the International Space Station (ISS). A slow\nammonia leak was detected using pressure and quantity telemetry five years after the P1\nEATCS was activated. The leak gradually accelerated to a rate that locating and isolating the\nleak became imperative to maintain cooling capability. Partial pressure measurements from\nthe Robotic External Leak Locator (RELL) scan surveys narrowed the search to the supply\nand return jumpers connecting one of three radiators to the system. Subsequently, the ISS\ncrew performed high definition video surveys during an Extravehicular Activity (EVA), or\nspacewalk, and ammonia flakes were observed projecting from the jumpers. Thus, the ground\nteams were confident that the culprit of the ammonia leak were the jumpers. The ammonia\nleak stopped after ground teams remotely isolated and vented those jumpers and associated\nradiator. Both jumpers were removed and returned to the ground, and a root cause\ninvestigation was conducted. A calibrated leak test determined the bulk of the ammonia leaked\nthrough a pair of seals in a Quick Disconnect (QD), or connector, on one end of the return\njumper. The return jumper QD was dissected, visually inspected, chemically tested and\nevaluated. The results indicated the most probable cause of the accelerating ammonia leak\nwas due to defective seals, plating delamination underneath the seals, and on-orbit thermal\ncycles exacerbating the delamination. Both jumpers were refurbished, relaunched to the ISS,\nand scheduled to be reinstalled during an EVA in 2022. It appeared the issue was unique, but\nrecently the S1 EATCS is showing signs of an accelerating ammonia leak, and RELL scans\nnarrowed the source to a similar pair of radiator jumpers.","isLessonsLearned":true,"disseminated":"DOCUMENT_AND_METADATA","cui":{"isCui":false,"submissionId":20220003097,"id":"7ff6dbbe0fdb436fb810fd6baf54ebd0"},"meetings":[{"country":"US","submissionId":20220003097,"endDate":"2022-07-14T05:00:00.0000000+00:00","sponsors":[{"organizationId":"5848f6aa95065acc8293f9097251ec21","meta":{"organization":{"name":"ILC Dover (United States)","location":"Dover, Delaware, United States"}},"meetingId":"e2b2cd29772c44518ff26887a0a55dcf","id":"09bb28262bda40c58126894d139b38b4"},{"organizationId":"d9746b6157e85e279e653fa4710cc840","meta":{"organization":{"name":"Paragon Space Development Corporation (United States)","location":"Tucson, Arizona, United States"}},"meetingId":"e2b2cd29772c44518ff26887a0a55dcf","id":"06118ddc79944cd0aa1ed0c3764bce42"},{"meta":{"organization":{"name":"Collins Aerospace"}},"meetingId":"e2b2cd29772c44518ff26887a0a55dcf","id":"00a3f0ed203d4b819bf68794f4793d39"}],"name":"International Conference on Environmental Systems","location":"Saint Paul, MN","id":"e2b2cd29772c44518ff26887a0a55dcf","url":"https://www.ices.space/","startDate":"2022-07-10T05:00:00.0000000+00:00"}],"publications":[{"submissionId":20220003097,"publisher":"","id":"ae9ee1e7ad664d89b423007d100cc9af","publicationName":"","url":""}],"status":"CURATED","related":[{"disseminated":"METADATA_ONLY","id":20210023733,"type":"SEE_ALSO","title":"Coolant Leak from ISS External Active Thermal Control System (EATCS) – An Examination of Most Probable ","stiType":"CONFERENCE_PAPER","distribution":"PUBLIC","status":"CURATED"}],"downloads":[{"draft":false,"mimetype":"application/pdf","name":"ICES_2022_145_Coolant Leak from ISS EATCS_2_21_2022.pdf","type":"STI","links":{"original":"/api/citations/20220003097/downloads/ICES_2022_145_Coolant%20Leak%20from%20ISS%20EATCS_2_21_2022.pdf","pdf":"/api/citations/20220003097/downloads/ICES_2022_145_Coolant%20Leak%20from%20ISS%20EATCS_2_21_2022.pdf","fulltext":"/api/citations/20220003097/downloads/ICES_2022_145_Coolant%20Leak%20from%20ISS%20EATCS_2_21_2022.pdf.txt"}}],"downloadsAvailable":true,"index":"submissions-2026-04-16-04-50"}