Gerry Anderson's "Supermarionation" series, such as Stingray, Thunderbirds, and Supercar, usually ended up in syndication when they came to the US. Not so with Fireball XL-5, which made its American debut on NBC a year after the series launched in England. Fireball would cycle through its 39 episodes over two seasons on NBC before joining its brethren in syndication, which is where I recall seeing it sometime in the early 70's, if memory serves.
Dennis Spooner, one of the show's writers, was more closely associated with ITC's line of spy & mystery series, such as Department S.
I don't have much memory of seeing the show, so we'll forego a rating. Meanwhile, Media Mix brings the opener, "Planet 46":