@prefix skos: . skos:prefLabel "ALOUETTE"@en ; a skos:Concept ; skos:narrower . skos:definition """Alouette-2 was a small space based ionospheric observatory instrumented with a sweep-frequency ionospheric sounder (radio transmitter), a VLF radio receiver, an energetic particle detector experiment, a cosmic radio noise experiment, and an electrostatic plasma probe. EXTERIOR ANTENNAS: The spacecraft used two long dipole antennas (73 meter and 22.8 meter, respectively) for the sounder, VLF, and radio cosmic noise experiments. SPACECRAFT ROTATION (SPIN): The satellite was spin-stabilized at about 2.25 rpm after antenna deployment. End plates on the 73 meter antenna corrected the rapid despin that had occurred on the predecessor spacecraft, Alouette 1, and which was believed to result from thermal distortion of the antenna and from radiation pressure. DATA ACQUISITION: There was no onboard tape recorder, so that data were available to the ground receiving station only when the spacecraft was in direct line of sight of telemetry stations. Telemetry stations were located so that primary data coverage was near the 80 degrees West meridan plus areas near Hawaii, Singapore, Australia, England, India, Norway and Central Africa. Initially data were recorded about 8 hours per day. Degradation of the power supply system had, by June 1975, reduced the operating time to about 1/2 hour per day. Routine operations were terminated in July 1975. The spacecraft was also successfully reactivated on November 28 and 29, 1975, in order to obtain data on its 10th anniversary. Group: Platform_Details Entry_ID: ALOUETTE-2 Group: Platform_Identification Platform_Category: Earth Observation Satellites Platform_Series_or_Entity: ALOUETTE Short_Name: ALOUETTE-2 End_Group Group: Synonymous_Platform_Names Short_Name: ALOUETTE-B Short_Name: 01804 End_Group Group: Platform_Associated_Instruments Short_Name: STEP FREQUENCY RADIOMETERS Short_Name: ELECTROSTATIC ANALYZERS End_Group Creation_Date: 2007-08-22 Online_Resource: http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1965-098A Group: Platform_Logistics Launch_Date: 1965-11-29 Primary_Sponsor: NASA End_Group End_Group"""@en ; skos:prefLabel "ALOUETTE-2"@en ; skos:inScheme ; skos:broader ; a skos:Concept .