That was the original type of communication satellite—the passive metal balloon,

https://en.wikipedia.org/wiki/Project_Echo ("Project Echo" (1960-69))

(Here's a historic irony: the field of radio astronomy was founded by people doing this stuff. The cosmic microwave background was discovered, by accident, with an RF horn built for this satellite relay experiment).

(Here's another weird one:)

https://en.wikipedia.org/wiki/Project_West_Ford ("Project West Ford" (1961-63)) ("The goal of the project was to place a ring of 480,000,000 copper dipole antennas in orbit to facilitate global radio communication")