Replica. This was the first satellite to transmit mesages in real time. Built by the American Telephone and Telegraph (AT&T) Company, it was a multi-faceted sphere 1metre in diameter, and was able to receive mesages from the ground, amplify them and then re-transmit them immediately, making it posible to send high-quality data such as television pictures. It was placed in a low orbit on 10th July 1962, and only 15 hours after launch transmitted live television pictures of a US flag blowing in the breeze in Maine to receivers in Britain and France.
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