O satélite de comunicações Echo I foi lançado há 63 anos

       

ECHO 1 e ECHO 2 eram satélites tecnológicos dos Estados Unidos, enormes balões em nylon, com 30 metros (ECHO 1) e 42 metros (ECHO 2) de diâmetro. Foram lançados, pela Agência Espacial Americana, (NASA), em 1960 e 1964, respetivamente.

Os Echos foram a origem dos satélites de comunicação passivos. Os resultados mais importantes deste programa espacial foram obtidos na aeronomia e geodésica. Em virtude de suas grandes dimensões e pequenas massas eles eram muito sensíveis à flutuações atmosféricas, o que permitiu determinar a densidade das camadas atmosféricas situadas entre 1000 e 1500 km de altitude, pela análise das variações observadas em seus períodos orbitais.

ECHO 1 e ECHO 2 também foram utilizados nas primeiras triangularizações geodésicas espaciais. O termo "ECHO" é um acrónimo formado pelas iniciais de "Experimental Contact Highlight Operation". "Echo" também significa "eco" em inglês. 

     

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O satélite de comunicações Echo I foi lançado há 62 anos

       

ECHO 1 e ECHO 2 eram satélites tecnológicos dos Estados Unidos, enormes balões em nylon, com 30 metros (ECHO 1) e 42 metros (ECHO 2) de diâmetro. Foram lançados, pela Agência Espacial Americana, (NASA), em 1960 e 1964, respetivamente.

O Echos foram a origem dos satélites de comunicação passivos. Os resultados mais importantes deste programa espacial foram obtidos na aeronomia e geodésica. Em virtude de suas grandes dimensões e pequenas massas eles eram muito sensíveis à flutuações atmosféricas, o que permitiu determinar a densidade das camadas atmosféricas situadas entre 1000 e 1500 km de altitude, pela análise das variações observadas em seus períodos orbitais.

ECHO 1 e ECHO 2 também foram utilizados nas primeiras triangularizações geodésicas espaciais. O termo "ECHO" é um acrónimo formado pelas iniciais de "Experimental Contact Highlight Operation". "Echo" também significa "eco" em inglês. 

     

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O Echo I, satélite de comunicações, foi lançado há 61 anos

       

ECHO 1 e ECHO 2 eram satélites tecnológicos dos Estados Unidos, enormes balões em nylon, com 30 metros (ECHO 1) e 42 metros (ECHO 2) de diâmetro. Foram lançados, pela Agência Espacial Americana, (NASA), em 1960 e 1964, respectivamente.

O Echos foram a origem dos satélites de comunicação passivos. Os resultados mais importantes deste programa espacial foram obtidos na aeronomia e geodésica. Em virtude de suas grandes dimensões e pequenas massas eles eram muito sensíveis à flutuações atmosféricas, o que permitiu determinar a densidade das camadas atmosféricas situadas entre 1000 e 1500 km de altitude, pela análise das variações observadas em seus períodos orbitais.

ECHO 1 e ECHO 2 também foram utilizados nas primeiras triangularizações geodésicas espaciais. O termo "ECHO" é um acrónimo formado pelas iniciais de "Experimental Contact Highlight Operation". "Echo" também significa "eco" em inglês. 

     

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NASA's Echo 1 satellite was built by Gilmore Schjeldahl's G.T. Schjeldahl Company in Northfield, Minnesota. The balloon satellite would function as a reflector, not a transceiver; after it was placed in a low Earth orbit, a signal could be sent to it, reflected by its surface, and returned to Earth.
During ground inflation tests, 40,000 pounds (18,000 kg) of air were needed to fill the balloon, but while in orbit, several pounds of gas were all that was required to fill the sphere. At launch, the balloon weighed 156.995 pounds (71.212 kg), including 33.34 pounds (15.12 kg) of sublimating powders of two types. According to NASA, "To keep the sphere inflated in spite of meteorite punctures and skin permeability, a make-up gas system using evaporating liquid or crystals of a subliming solid were [sic] incorporated inside the satellite." One of the powders weighed 10 pounds (4.5 kg), with a very high vapor pressure; the other had a much lower vapor pressure.
The first attempt to orbit an Echo satellite (also the maiden voyage of the Thor-Delta launch vehicle) miscarried when Echo 1 lifted off from Cape Canaveral's LC-17A on the morning of May 13, 1960. The Thor stage performed properly, but during the coasting phase, the attitude control jets on the unproven Delta stage failed to ignite, sending the payload into the Atlantic Ocean instead of into orbit.
Echo 1A (commonly referred to as Echo 1) was successfully put into a orbit of 944 to 1,048 miles (1,519 to 1,687 km) by another Thor-Delta, and a microwave transmission from the Jet Propulsion Laboratory in Pasadena, California, was relayed by the satellite to Bell Laboratories in Holmdel, New Jersey, on August 12, 1960.
The 30.5-meter (100 ft) diameter balloon was made of 0.5-mil-thick (12.7 μm) biaxially oriented PET film, metalized at a thickness of 0.2 micrometers (0.00787 mils) (a type of film commonly known by the trade name Mylar), and had a total mass of 180 kilograms (397 lb). It was used to redirect transcontinental and intercontinental telephone, radio, and television signals. It also had 107.9 MHz telemetry beacons, powered by five nickel-cadmium batteries that were charged by 70 solar cells mounted on the balloon. The spacecraft aided the calculation of atmospheric density and solar pressure, due to its large area-to-mass ratio. During the latter portion of its life, it was used to evaluate the technical feasibility of satellite triangulation.
As its shiny surface was also reflective in the range of visible light, Echo 1A was easily visible to the unaided eye over most of the Earth.
The spacecraft was nicknamed a "satelloon" by those involved in the project (a portmanteau combining satellite and balloon).
It was originally expected that Echo 1A would not survive long after its fourth dip into the atmosphere in July 1963, although estimates allowed the possibility that it would continue to orbit until 1964 or beyond. It ended up surviving much longer than expected, and finally reentered Earth's atmosphere and burned up on May 24, 1968.
     

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O satélite de comunicações Echo I foi lançado há sessenta anos

      

ECHO 1 e ECHO 2 eram satélites tecnológicos dos Estados Unidos, enormes balões em nylon, com 30 metros (ECHO 1) e 42 metros (ECHO 2) de diâmetro. Foram lançados, pela Agência Espacial Americana, (NASA), em 1960 e 1964, respectivamente.

O Echos foram a origem dos satélites de comunicação passivos. Os resultados mais importantes deste programa espacial foram obtidos na aeronomia e geodésica. Em virtude de suas grandes dimensões e pequenas massas eles eram muito sensíveis à flutuações atmosféricas, o que permitiu determinar a densidade das camadas atmosféricas situadas entre 1000 e 1500 km de altitude, pela análise das variações observadas em seus períodos orbitais.

ECHO 1 e ECHO 2 também foram utilizados nas primeiras triangularizações geodésicas espaciais. O termo "ECHO" é um acrónimo formado pelas iniciais de "Experimental Contact Highlight Operation". "Echo" também significa "eco" em inglês. 

   

in Wikipédia

   
NASA's Echo 1 satellite was built by Gilmore Schjeldahl's G.T. Schjeldahl Company in Northfield, Minnesota. The balloon satellite would function as a reflector, not a transceiver; after it was placed in a low Earth orbit, a signal could be sent to it, reflected by its surface, and returned to Earth.
During ground inflation tests, 40,000 pounds (18,000 kg) of air were needed to fill the balloon, but while in orbit, several pounds of gas were all that was required to fill the sphere. At launch, the balloon weighed 156.995 pounds (71.212 kg), including 33.34 pounds (15.12 kg) of sublimating powders of two types. According to NASA, "To keep the sphere inflated in spite of meteorite punctures and skin permeability, a make-up gas system using evaporating liquid or crystals of a subliming solid were [sic] incorporated inside the satellite." One of the powders weighed 10 pounds (4.5 kg), with a very high vapor pressure; the other had a much lower vapor pressure.
The first attempt to orbit an Echo satellite (also the maiden voyage of the Thor-Delta launch vehicle) miscarried when Echo 1 lifted off from Cape Canaveral's LC-17A on the morning of May 13, 1960. The Thor stage performed properly, but during the coasting phase, the attitude control jets on the unproven Delta stage failed to ignite, sending the payload into the Atlantic Ocean instead of into orbit.
Echo 1A (commonly referred to as Echo 1) was successfully put into a orbit of 944 to 1,048 miles (1,519 to 1,687 km) by another Thor-Delta, and a microwave transmission from the Jet Propulsion Laboratory in Pasadena, California, was relayed by the satellite to Bell Laboratories in Holmdel, New Jersey, on August 12, 1960.
The 30.5-meter (100 ft) diameter balloon was made of 0.5-mil-thick (12.7 μm) biaxially oriented PET film, metalized at a thickness of 0.2 micrometers (0.00787 mils) (a type of film commonly known by the trade name Mylar), and had a total mass of 180 kilograms (397 lb). It was used to redirect transcontinental and intercontinental telephone, radio, and television signals. It also had 107.9 MHz telemetry beacons, powered by five nickel-cadmium batteries that were charged by 70 solar cells mounted on the balloon. The spacecraft aided the calculation of atmospheric density and solar pressure, due to its large area-to-mass ratio. During the latter portion of its life, it was used to evaluate the technical feasibility of satellite triangulation.
As its shiny surface was also reflective in the range of visible light, Echo 1A was easily visible to the unaided eye over most of the Earth.
The spacecraft was nicknamed a "satelloon" by those involved in the project (a portmanteau combining satellite and balloon).
It was originally expected that Echo 1A would not survive long after its fourth dip into the atmosphere in July 1963, although estimates allowed the possibility that it would continue to orbit until 1964 or beyond. It ended up surviving much longer than expected, and finally reentered Earth's atmosphere and burned up on May 24, 1968.
   

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