Nova was a robotic winged horse owned by Tobias Manning.
Tobias Manning acquired the robotic horse on one of his many trips to the future. He tried to escape Ohiyesa Smith with it, but it crashed and was destroyed. Its remains were cast off into space along with the other future tech by Green Lantern.
Nova first appeared with Manning in Superman #249, though he wasn't named until the following issue. In the comics, it was not a robot; it was an Arguvian space-steed.