Editing Project Echo (section)

== Legacy ==
[[File:Echo I 1960 Issue-4c.jpg|thumb|Echo 1 stamp – 1960 issue]]
Project Echo facilitated the first successful satellite transmission and first two way communications between the JPL Goldstone facility and Bell Telephone Laboratories facility in Holmdel, New Jersey. Other groups participated in experiments including the [[Collins Radio Company]] and the [[United States Naval Research Laboratory|Naval Research laboratory]]. Because Echo was only a passive system, it was primarily useful in demonstrating the future potential of satellite communications and became obsolete before it deorbited in 1968. Echo was most known to the general public for its visibility as it could be seen at night with the naked eye.<ref name="Butrica1997"/>

The Echo satellite program also provided the astronomical reference points required to accurately locate [[Moscow]]. This improved accuracy was sought by the U.S. military for the purpose of targeting intercontinental ballistic missiles.<ref>{{cite book|title=Angle of Attack: Harrison Storms and the Race to the Moon|last=Gray|first=Mike|year=1992|publisher=W. W. Norton & Co|isbn=0-393-01892-X|pages=[https://archive.org/details/angleofattackhar0000gray/page/5 5–6]|url=https://archive.org/details/angleofattackhar0000gray/page/5}}</ref>

The [[Holmdel Horn Antenna|large horn antenna at Holmdel]] constructed by Bell Labs for the Echo project was later used by [[Arno Penzias]] and [[Robert Woodrow Wilson]] for their [[Nobel Prize]]-winning discovery of the [[cosmic microwave background radiation]].<ref>{{cite web|url=http://nobelprize.org/nobel_prizes/physics/laureates/1978/penzias-bio.html|title=Arno Penzias - Biographical |website=nobelprize.org}}</ref>

On 15 December 1960, the U.S. Post Office issued [[U.S. space exploration history on U.S. stamps|a postage stamp]] depicting Echo 1.