Bussard Ramjet

The Bussard ramjet was a form of subluminal propulsion common on human-manufactured vessels, and especially prominent beyond the 2240s.

Unlike its original intention (per Robert Bussard), the ramjets present on starships was only capable of effectively functioning within atmosphere. The intakes still utilized electromagnetic collection methods when necessary, but functioned with more similarities to an atmospheric ramjet than an interstellar ramjet.