The Zirkiv was a 24th century replica of a 21st century Earth Cargo Service freighter. It was built by Stammartie Holl and her two children from salvaged parts of old ECS vessels, and used as both a working supply ship and a tourist attraction. The Zirkiv is described as looking like "a three-hundred-and-fifty-year-old Earth Cargo Service vessel," which would date it to 2031, predating Zefram Cochrane's first warp flight. This may suggest the ECS existed prior to interstellar flight, operating between planets in the Sol system.