http://en.wikipedia.org/wiki/Astro
And yes, "astro" was already a common word long before Astro Boy came along, not the other way around.
Hopefully I have now dramatically lowered the number of future topics about this.

EDIT: how about that, "Project names of astronomy satellites developed by ISAS (now JAXA) — ASTRO-A (Hinotori i.e. 'Phoenix'), ASTRO-B (Tenma)"
o_o