Thor hit the sky quickly in his fight with the destroyer and once in the sky showed the ability to rain lightning bolts into multiple targets (whilst bleeding from enchanted dagger wound).
Such bolts should halt or phase a machine like Astro. Then Hulk jumps on him and pounds him into the earth until shattered.
Or Tony cuts him up with the red lasers. Or Hawkeye shoots an arrow onto him that destroyed a chunk of the helicarrier.
LoL, you people. Lightning isn't doing jack nor shit to him.
Astroboy took several blast and several barrages of missiles in direct hits until be was finally KO'd and fell from the city all the way down to earth. This was when he wasn't fighting back and recently discovered he was a machine.
Edit: Here's the full movie, you gays. http://www.youtube.com/watch?v=LIcQFdSRhoI