@prefix skos: . @prefix ns0: . skos:prefLabel "Solar/Space Observation Satellites"@en ; a skos:Concept ; skos:narrower . ns0:resource [ ] ; ns0:altLabel [ ] ; skos:definition """The Solar Maximum Mission (SMM) was designed to provide coordinated observations of solar activity, in particular solar flares, during a period of maximum solar activity. The payload was made up of seven instruments, specifically selected to study the short-wavelength and coronal manifestations of flares. The total solar irradiance was measured by ACRIM, gamma rays by GRS, hard X-rays by the HXRBS, soft X-rays by XRP and HXIS, ultraviolet by UVSP, and the C/P imaged the corona 2-5 radii from the sun. Data were obtained on the storage and release of flare energy, particle acceleration, formation of hot plasma, and mass ejection. Complementary studies were made as part of the SMM guest investigator program, and coordinated in-situ measurements of flare particle emissions were made from the ISEE-3 spacecraft. The SMM observatory was of modular construction and measured approximately 4 m in length, fitting into a circular envelope 2.3 m in diameter. The instrument module occupied the top 2.3 m and contained all the solar payload instruments together with the fine-pointing Sun-sensor system. Below the instrument module was the Multimission Modular Spacecraft (MMS) containing the systems for attitude control, power, communication, and data handling. Between the instrument module and the MMS was the transition adaptor, supporting two fixed solar paddles that supplied between 1500 and 3000 W of power. Quick and coordinated responses to solar flares were considered essential for meeting the scientific objectives of the mission. Therefore, the ground system was designed to facilitate coordinated data evaluation, observation, planning, and command uplink to the onboard stored command processor. Onboard coordination of response to a flare was performed in real time. The attitude-control software allowed observatory repointings and slow scanning motions; there was also a special module for tracking a solar feature over many days. A repair mission by the space shuttle (STS-41C) was performed in 1984. During the repair mission the Shuttle astronauts rendezvoused with SMM and replaced successfully some hardware. As a result the coronagraph observations resumed until the end of mission. SMM collected data until Nov. 24, 1989, and re-entered on Dec. 2, 1989. For more details, see E. G. Chipman, Ap. J., v. 244, p. L113, 1981, and J. D. Bohlin et al., Solar Phys., v. 65, p. 5,1980. LAUNCH DATE- 02/14/80 ORBIT PARAMETERS ORBIT TYPE- GEOCENTRIC EPOCH DATE- 02/15/80 ORBIT PERIOD- 94.8 MIN INCLINATION- 28.5 DEG PERIAPSIS- 508. KM ALT APOAPSIS- 512. KM ALT Group: Platform_Details Entry_ID: SMM Group: Platform_Identification Platform_Category: Solar/Space Observation Satellites Short_Name: SMM Long_Name: Solar Maximum Mission End_Group Group: Synonymous_Platform_Names Short_Name: Solar Max Short_Name: Solar Maximum Mission Short_Name: 1980-014A Short_Name: 11703 End_Group Group: Platform_Associated_Instruments Short_Name: ACRIM Short_Name: UVSP Short_Name: HXRBS End_Group Group: Orbit Orbit_Inclination: 28.5 degrees Period: 94.8 m Perigee: 508 km Apogee: 512 km Orbit_Type: LEO > Low Earth Orbit > Inclined Non-Polar End_Group Online_Resource: http://umbra.nascom.nasa.gov/smm/ Sample_Image: http://nssdc.gsfc.nasa.gov/image/spacecraft/smm_capture.jpg Group: Platform_Logistics Launch_Date: 1980-02-14 Launch_Site: Cape Canaveral/Kennedy Space Center, USA Primary_Sponsor: NASA End_Group End_Group"""@en ; skos:prefLabel "SMM"@en ; skos:inScheme ; skos:broader ; a skos:Concept .