Pictured above is an animation of the Explorer orbiting Earth and a scale model of the
satellite being held up by (left to right) William Pickering, James Von Allen, and Wernher 
Von Braun. 

Explorer 1  was the first Earth satellite of the United States, launched as part of its participation in an international scientific project. The mission followed the first two
Earth satellites the previous year, the Soviet Union’s Sputnic l and 2, beginning the
Cold War Space Race between the two nations.

Explorer 1 was launched  atop the first Juno booster from at the Cape Canaveral, Florida. It returned data until its batteries were exhausted after nearly four months. It remained in orbit until 1970.

One of the first people to build a telephone exchange was Hungarian Tivadar Puskas (above) in 1877 while he was working for Thomas Edison. George W. Coy designed and built the first commercial telephone exchange which opened in New Haven, Connecticut. He’s been called the first full-time telephone operator. The switchboard was built from "carriage bolts, handles from teapot lids and bustle wire" and could handle two simultaneous conversations .

    
              The first telephone switchboard built by George W. Coy

Hollywood-based KTLA-TV Channel 5 in Los Angeles, was the first commercially licensed television station west of the Mississippi. It first aired a 30-minute variety show from the Paramount TV theatre starring Bob Hope , Dorothy Lamour, William Bendix and Jerry Colonna. It was estimated that 322 television receivers were in use in Los Angeles at the time.

                                  The KTLA studios in 1949

USS Nautilus (SSN-571) is the world’s first operational nuclear-powered submarine. She was also the first vessel to complete a submerged transit across the North Pole.

Namesake of the submarine in Jules Vern’s Twenty Thousand Leagues Under the Sea, Nautilus was authorized in 1951 and launched in 1954. Because her nuclear propulsion allowed her to remain submerged for far longer than diesel-electric submarines, she broke many records in her first years of operation and was able to travel to locations previously beyond the limits of submarines. In operation, she revealed a number of limitations in her design and construction; this information was used to improve subsequent submarines.

The Nautilus was decommissioned in 1980 and designated a National Historic Landmark in 1982. She has been preserved as a museum of submarine history in Groton, Connecticut where she was launched. she receives some 250,000 visitors a year.

Another photo of the Launching of the USS Nautilus showing the spectators

The Nautilus docked at the U.S. Navy Submarine Force Library and Museum
located at Gorton, Connecticut.