When does Astro Boy return?

Astro Boy is a Japanese anime television series based on Osamu Tezuka's manga series of the same name. The show is set in 2003, where a variety of robots have been developed around the world and have begun working at the humans' beck and call, but are nothing more than machines that move on command. In the midst of this, in Metro City, the renowned Dr. Tenma disappears after trying to construct an AI robot with a "heart" Professor Ochanomizu replaces Tenma as head of the Ministry of Science and brings it to life and names him Atom (Astro)