My dad designed the Minitrack tracking system and the test vehicle satellites. The Vanguard proposal in 1955 was superior to the Army’s proposal in terms of its scientific uses. Originally vB didn’t have a radio tracking system for what became Explorer. https://www.youtube.com/watch?v=HS72o86aeZo
Here’s an article I wrote about the 60th.
https://thespacereview.com/article/3477/1