Yes Jetter Mars was a robot boy. He was the 70's version of Astro. He was re-designed and his name changed to Jetter Mars(Jetter Marusu), because Tezuka, having lost Mushi Productions due to bankruptcy, took a job at Toei Productions in the late 70's, and not being able to secure the rights to Astro, had to make last minute changes to the main characters, but the story and supporting chracacters are the same as in Astro Boy. By 1980, he had a new company and the full rights to all his creations. I've read all this behind the scenes stuff on the Jetter Mars site and other places.
Here's what the Tezuka site has on Jetter:
http://en-f.tezuka.co.jp/anime/sakuhin/ts/ts016.htmlUnfortunately there's no episode list or preview, but I found the begining theme in Italian on this site:
http://regnodelleanime.gamesurf.it/filtro/.../capitanjet.htmCool huh? It's the same theme as the Japanese version, just sung in Italian. I love the artwork and colors and you can see he's basically Astro.

Recignize the headless robot Dam Dam? Evan the villians are the same. Ohh for all you Rock fans, he's in the show too. Unfortunately, Hamegg is too. Maybe Astro/Jetter kicks his butt this time.
