Another find by Mike Burrows is the Flame King space liner, which served as the origin of the Nuclear Freighter. Drawn by Mike Noble, it appears in the Fireball XL5 episode in TV21 #71, published 4 June 1966.
After having rescued the crew of a previous victim of the black ships, Steve Zodiac and crew watch a video report on the attack and capture of the space liner. In the same episode, the reader is shown the mysterious pirates aren't so much after loot, but actually capture spaceships to steal their technology. Their leader is shown commenting that the pirates' technology is years behind that used in Fireball XL5, and orders his henchmen to capture Zodiac's ship.