"Specifically, they need to show off a rocket-propelled vehicle and payload that 'takes off vertically, climbs to a defined altitude, flies for a pre-determined amount of time, and then land vertically on a target that is a fixed distance from the launch pad.'"

Didn't NASA already accomplish that with the Apollo missions?

Best Buy is the Bestest!

It's so shiny!

Rock on!

Look closely at the image above. Notice that white, cross-like thing in the top-right corner? That's a sweeping mechanism specifically for corners.

The reason they don't make the Roomba square is because that would require a lot of back-and-forth to actually get into the corner. Even then, it won't get into the absolute corner because of the housing.

So, that little sweeping mechanism spins in a counter-clockwise direction the whole time the Roomba is running and kicks anything in a corner out of the corner and into the path of the Roomba.

This is also why the Roomba always runs its right side, and never its left side, against walls.