Conceptual question on momentum

[Bob Loblaw]

Homework Statement

An astronaut is on a space walk when his tether breaks. He has no rocket pack, only a big wrench. How does he get back to the ship?

Homework Equations

p=mv

The Attempt at a Solution

I have no idea. I imagined him using the wrench as some sort of "paddle" as he space-canoed his way back to the ship. Any more realistic ideas?

 

[learningphysics]

Think conservation of linear momentum. paddle won't work because there's only empty space there... nothing to push against.