@prefix skos: . @prefix ns0: . skos:prefLabel "Earth Observation Satellites"@en ; a skos:Concept ; skos:narrower . ns0:resource [ ] ; ns0:altLabel [ ] ; skos:definition """The Combined Release and Radiation Effects Satellite (CRRES) Program is comprised of several elements. One is the release of powdered and liquid chemicals during the first 45 to 60 days after launch, when the spacecraft is in its 300-km altitude circular orbit. These releases are used to study electric fields, neutral winds, and other phenomena in the upper atmosphere, the ionosphere, and the magnetosphere. The spacecraft spins at 20 rpm during the low altitude orbit phase of the program. After the chemical releases are completed, the satellite is boosted into a geosynchronous-transfer-type orbit and spun down to 2 rpm. The orbit parameters of this final orbit are as follows: apogee altitude - 35,800 km, perigee altitude - 400 km, period - 630 min, inclination - about 16 deg. As the satellite traverses the inner magnetosphere, a full complement of field, particle, and plasma instruments measures the radiation environment. A comprehensive set of state-of-the-art microelectronics devices and other spacecraft components are tested in orbit for radiation effects. A major segment of the CRRES payload is part of AFGL's Space Radiation Effects Program (SPACERAD). The SPACERAD Program is a comprehensive space and ground test effort to (a) measure radiation-induced single event upsets and total dose degradation of state-of-the-art microelectronics devices, including VHSIC and GaAs, in a known space environment; (b) perform laboratory radiation response and annealing characterization of parts identical to those flown on CRRES; (c) develop algorithms to relate space performance of microelectronic components to ground test procedures, and update existing radiation ground test guidelines to more accurately simulate the behavior of devices in space; (d) space qualify advanced technology devices for use in operational systems; (e) update the static models of the radiation belts; and (f) develop the first dynamic models of the high-energy particle populations. The on-orbit phase of SPACERAD lasts for about 3 years. In addition, there are other radiation belt experiments on CRRES provided by the Navy. The CRRES spacecraft has the shape of an octagonal prism with solar arrays on the top side. The prism is 1 m high and 3 m between opposite faces. Four of the eight compartments are for the chemical canisters and the other four house the SPACERAD and other experiments. The spin axis of CRRES is controlled so that it points at the sun. Spacecraft Orbit Information Launch Date and Time 07/25/90 Orbit Type Elliptical Anomalistic Period 591.9 Min Apogee(km) 33612. Perigee(km) 335. Inclination 18.2 Group: Platform_Details Entry_ID: CRRES Group: Platform_Identification Platform_Category: Earth Observation Satellites Short_Name: CRRES Long_Name: Combined Release and Radiation Effects Satellite End_Group Group: Synonymous_Platform_Names Short_Name: CRRES End_Group Group: Orbit Orbit_Inclination: 18.2 Period: 591.9 min Perigee: 335 km Apogee: 33612 km Orbit_Type: HEO > Highly Elliptical Orbit End_Group Creation_Date: 2007-11-19 Online_Resource: http://www.spenvis.oma.be/spenvis/help/models/databases/crres.html Online_Resource: http://nssdc.gsfc.nasa.gov/nmc/masterCatalog.do?sc=1990-065A Sample_Image: http://library01.gsfc.nasa.gov/gdprojs/images/crres.jpg Group: Platform_Logistics Launch_Date: 1990-07-25 Launch_Site: Cape Canaveral/Kennedy Space Center, USA Primary_Sponsor: USA/NASA End_Group End_Group"""@en ; skos:prefLabel "CRRES"@en ; skos:inScheme ; skos:broader ; a skos:Concept .