Who's This? The rocket age trio on page 8 of Who's Who vol.XXII.
How you could have heard of them: Twisted versions of the Rovers were main characters in Howard Chaykin's Twilight mini-series and subsequent Iron Wolf graphic novel (1990-1992). They also appeared in that catch-all of space opera obscura, Starman #55 (1999), which in fact, mirrored the triple-POV structure of their original stories. More recently, they were introduced as space smugglers in the New52's Green Lantern: New Guardians Annual #1 (2013), and are later hired by Larfleeze in a Threshold back-up. Same names, one extra member, no real relation.
Example story: Mystery in Space #80 (1962) by Gardner Fox and Sid Greene, reprinted in From Beyond the Unknown #18 (1972) and DC Super-Stars #8 (1976)
Who else? The next character will have a metal-based code name. Which doesn't actually narrow it down much.