[1] Intermediate System - Intermediate System

[2] Integration von Software Informationssystemen

[3] Integrated Systems and Information Services

[4] International Satellites for Ionospheric Studies - amerik./kanad. Ionosphärensatellitenserie ab 1968 {Weltraumfahrt}/{Astronomie}

[5] Intelligentes Satellitendaten Informationssystem (DLR) {Astronomie}

[6] International Science Information Service (->"IEEE Standard Dictionary")

[7] Internal Switched Interface System (->"Lexikon der Text- und Datenkommunikation")

[8] Inflatable Sunshield In Space (->"NASA NGST Acronym List")