ASTM_E_2900_-_12.pdf

Designation:E290012Standard Practice forSpacecraft Hardware Thermal Vacuum Bakeout1This standard is issued under the fixed designation E2900;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice establishes methods for thermal vacuumbakeout of spacecraft and spacecraft components.1.2 This practice defines the equipment,environment,andcertification criteria for each type of bakeout.1.3 The methods defined in this practice are intended toreduce component outgassing rates to levels necessary to meetmission performance requirements of the contamination sensi-tive hardware.Times,temperatures,and configurations con-tained in this document have been found to provide satisfactoryresults.Experienced operators may find that other,similartimes,temperatures and configurations have provided satisfac-tory results.If deviations from these criteria are deemedappropriate,they should be detailed in the bakeout report.1.4 This practice describes three bakeout methods:MethodA,using prescribed time and pressure criteria;Method B,usingprescribed QCM stabilization rate criteria;and Method C,which measures the QCM deposition rate.1.5 Determination of the acceptable molecular outgassing,selection of the bakeout method,and determination of thespecific test completion criteria are the responsibility of theuser organization.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E1546 Guide for Development of Fire-Hazard-AssessmentStandardsE296 Practice for Ionization Gage Application to SpaceSimulatorsE834 Practice for Determining Vacuum Chamber GaseousEnvironment Using a Cold FingerE1234 Practice for Handling,Transporting,and InstallingNonvolatile Residue(NVR)Sample Plates Used in Envi-ronmentally Controlled Areas for SpacecraftE1235 Test Method for Gravimetric Determination of Non-volatile Residue(NVR)in Environmentally ControlledAreas for SpacecraftE1549 Specification for ESD Controlled Garments Requiredin Cleanrooms and Controlled Environments for Space-craft for Non-Hazardous and Hazardous OperationsE1559 Test Method for Contamination Outgassing Charac-teristics of Spacecraft MaterialsE1560 Test Method for Gravimetric Determination of Non-volatile Residue From Cleanroom WipersE1731 Test Method for Gravimetric Determination of Non-volatile Residue from Cleanroom GlovesE2311 Practice for QCM Measurement of Spacecraft Mo-lecular Contamination in Space2.2 Other Standards:IEST-STD-CC1246 Product Cleanliness Levels and Con-tamination Control Program3MIL-STD-1246 Product Cleanliness Levels and Contamina-tion Control Program4,5MIL-P-27401 Propellant Pressurizing Agent,Nitrogen5ISO-14644 Cleanrooms and associated clean environments3FED-STD-209 Federal Standard,Airborne ParticulateCleanliness Classes in Cleanrooms and Clean Zones5,63.Terminology3.1 Definitions:3.1.1 ambient conditions,nroom temperature and pres-sure.3.1.2 pre-bakeout,nto clean or condition,or both,avacuum chamber prior to its use for flight hardware.1This test method is under the jurisdiction of ASTM Committee E21 on SpaceSimulation and Applications of Space Technology and is the direct responsibility ofSubcommittee E21.05 on Contamination.Current edition approved Nov.1,2012.Published December 2012.DOI:10.1520/E2900-12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from Institute of Environmental Sciences and Technology(IEST),Arlington Place One,2340 S.Arlington Heights Rd.,Suite 100,Arlington Heights,IL 60005-4516,http:/www.iest.org.4MIL-STD-1246 may be used in lieu of IEST-STD-CC1246 by mutual agree-ment of the parties in the contract.5Available from DLA Document Services,Building 4/D,700 Robbins Ave.,Philadelphia,PA 19111-5094,https:/assist.daps.dla.mil/quicksearch/6FED-STD-209 may be used in lieu of ISO-14644 by mutual agreement of theparties in the contract.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.3 bakeout,na process by which volatile molecularcontaminants are removed from a spacecraft component orarticle by exposing it to vacuum and elevated temperature”.When the intent is to describe an action,this should be twowords:to“bake out”.3.1.4 cold finger,nthe device that is used in collecting thesample of the residual gases in an evacuated vacuum chamber.3.1.5 cold plate,na vacuum st