Galaxy IV was a model HS-601 satellite built by Hughes Space and Communications Company (HSC). The satellite, which carried a payload of both C band and Ku band transponders, was launched on June 24, 1993 and operated by PanAmSat Corporation. U.S. military MILSTAR communications satellite A communications satellite (sometimes abbreviated to comsat) is an artificial satellite stationed in space for the purposes of telecommunications using radio at microwave frequencies. ... C band (compromise band) is a portion of electromagnetic spectrum in the microwave range of frequencies ranging from 4 to 6 GHz. ... The Ku band (kay-yoo kurz-under band) is a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 11 to 18 GHz. ... In telecommunication, the term transponder (sometimes abbreviated to XPDR or TPDR) has the following meanings: An automatic device that receives, amplifies, and retransmits a signal on a different frequency. ... June 24 is the 175th day of the year (176th in leap years) in the Gregorian Calendar, with 190 days remaining. ... 1993 is a common year starting on Friday of the Gregorian calendar and marked the Beginning of the International Decade to Combat Racism and Racial Discrimination (1993-2003) Events Media:January January 1 - Czechoslovakia divides. ... Founded in 1984 by Rene Anselmo, PanAmSat is a satellite service provider headquartered in Wilton, CT. It operates a fleet of communications satellites used by the entertainment industry, news agencies, internet service providers and telecommunication companies. ...

Control of Galaxy IV was lost on May 19, 1998 when the satellite's primary control processor failed. The backup control processor had suffered a previously undetected anomaly, and PanAmSat was not able to regain control of the spacecraft. Galaxy IV was declared a loss on May 20, 1998. Failure of the primary control processor was atributed to Tin Whisker growth. May 19 is the 139th day of the year in the Gregorian Calendar (140th in leap years). ... 1998 is a common year starting on Thursday of the Gregorian calendar, and was designated the International Year of the Ocean. ... May 20 is the 140th day of the year in the Gregorian Calendar (141st in leap years). ... 1998 is a common year starting on Thursday of the Gregorian calendar, and was designated the International Year of the Ocean. ... Metal whiskers are a crystalline metallurgical phenomenon whereby metal grows tiny, filiform hairs. ...

At the time of failure, Galaxy IV was in geostationary orbit at 99°W. This orbital slot is now occouped by the Galaxy 4R satellite. A geostationary orbit (abbreviated GEO) is a circular orbit in the Earths equatorial plane, any point on which revolves about the Earth in the same direction and with the same period as the Earths rotation. ...