“10 July 1962: At 0835 GMT (4:35 a.m., EDT) the first communications relay satellite, Telstar 1, was launched into Earth orbit from Launch Complex 17B, Cape Canaveral Air Force Station, Florida. The launch vehicle was a three-stage liquid-fueled Delta rocket.
This was the first commercial space flight, sponsored by a consortium of communications companies and government organizations, including AT&T, Bell Labs, the BBC, NASA, and British and French postal services. The satellite was used to relay live television broadcasts across the Atlantic Ocean. This had never previously been possible…
In addition to its primary role as a communications relay satellite, Telstar also performed scientific experiments to study the Van Allen Belt.
The Delta was a three-stage expendable launch vehicle which was developed from the Douglas Aircraft Company’s SM-75 Thor intermediate-range ballistic missile…
Telstar is still in Earth orbit.” 
Source: https://www.thisdayinaviation.com/10-july-1962/