SDF-7 was a designation used in the Robotech II: The Sentinels novels to identify the new vessel used by the Sentinels after the destruction of the Farrago. Additional ships of the same class were constructed, and were referred to as SDF-7-class ships. One such SDF-7-class ship named in the novels was the Ark Angel (not to be confused the Angel class ship named the Ark Angel that appears in The Shadow Chronicles). This ship was the one used to rescue the Sentinels from the doomed planet of Praxis. The ship was then used as the Sentinel's flagship for the rest of The Sentinels' novels. Since the reboot of the series with Robotech: The Shadow Chronicles and the Prelude to the Shadow Chronicles comics/graphic novel, this designation has become obsolete.