"January 31, 2008 marks the 50th anniversary of the launch of the first U.S. satellite - Explorer I - and the dawn of the U.S. space program. Leaders of the U.S. House Committee on Science and Technology marked that anniversary with the introduction of a U.S. House Resolution late yesterday remembering the landmark day and the remarkable advances the U.S. space program has yielded."
The following 4 videos offer different views of the launch and mission of Explorer 1. In the first video, MSgt. Stuart Queen talks about the Explorer 1 launch: "as a giant rocket was catapaulted into outer space".
NASA: Explorer 1 -- JPL and the Beginnings of the Space Age
First U.S. Satellite launched - newsreel