Floating silently above the closing Exposition, the U.S.S. Hephaestus embarks on her shakedown cruise. While the lead boat of a planned class of six, events overtook her and the U.S.S. Weyland was never completed. The remaining four vessels were canceled before construction began.
While very much of the prewar character, with her riveted steel hull and naval bearing, she was also the first US ship to be fitted with a gravity engine derived from Martian designs. Experience here would later translate into the advances embodied in the 'Nevada' class, as well as have significant implications for the colonization of Mars herself.