7 robots too expensive (or lethal) to own

The Protector is something of a lookout for soldiers. Its massive digging tool sets off buried explosives -- so you don't.

That's particularly important in modern warfare. Improvised explosive devices have become increasingly common and harder to detect. The Protector, at a bulky 1,000 pounds, can remove the top three inches of soil while traveling 5 mph.

It's a transformer too. Clear the top, and it's a stretcher. Add HDT's robot arms, and suddenly it's humanoid. Add a backhoe, and it's a construction robot. You can even attach something called an Anti-Personnel Obstacle Breaching System: a bazooka that shoots an explosive line of charges that clears a path through a minefield.