They call it the Pipe Snake.

Designed to infiltrate a building's plumbing system, the Pipe Snake can navigate everything from steep, vertical climbs to elbow-curves. But its primary purpose isn't to neutralize bad guys. In fact, it's one of a growing class of unmanned tools designed to help first-responders reach trapped disaster victims.

In the midst of a natural disaster, getting information about who or what may be inside a downed building can be unsafe. So Lt. Kyle Fitle and David Carte, who graduated this year from the U.S. Air Force Academy, decided to MacGyver their way to a solution.

The result involves a telescoping metal rod with extendable arms coming out from the sides. The arms are equipped with pads that grip the walls of a sewage pipe, while a built-in motor alternately retracts the arms and extends the rod to push it forward while another set of arms holds the snake in place.

It's a complex engineering problem, particularly if you're trying to fight the flow of waste going in the other direction. To adapt, Fitle and Carte discovered that deploying the arms at just the right angle created what they called a "lockout" condition.

"It's the point at which downward pressure from the sewer increases the friction of the feet pushing against the wall faster than the whole system can slip downward," Carte said at a Washington conference Monday on drone technology. "So what happens is, your system becomes limited by structural integrity rather than slippage."

Future automated versions of the Pipe Snake will be able to carry payloads of bandages or pills to trapped disaster victims. But what if the pipes are broken, or the tubes are clogged? For that, Fitle and Carte came up with another solution.

Fans of the Splinter Cell franchise would recognize it instantly: A projectile that sticks to walls and can feed live intelligence about what's in a room back to a smartphone or a tablet.

The Adhesive Pellet Projectile is about the size of a large household battery. Its hollow, cone-shaped shell can accept infrared and audio sensors. Using a few fishhooks and a modified paintball gun as a pneumatic cannon, the graduates figured out how to make the pellets stick to a variety of surfaces. Fitle said they even experimented with the ability to fire the pellets remotely.

Eventually, Fitle and Carte want to be able to daisy-chain multiple pellets so that if the signal can't get back to the user directly from inside a building, it can be wirelessly transmitted to another pellet with better reception.

Even though the tools are designed with first responders in mind, it's impossible to look at them and not see battlefield or other tactical applications. Fitle virtually admitted as much when he said their adhesive pellets could be used to pursue drug traffickers or secure the U.S. border with Mexico.

"These could be miniaturized to be attached to people illegally entering the country," Fitle said, "and help the Border Patrol track illegal immigrants more effectively."

If that sounds creepy, you should hear their plans for the Pipe Snake. Fitle and Carte imagine modifying the drone so that it can punch holes in the pipe and release a swarm of nano robots.

Those advances would no doubt help emergency workers gather information about trapped individuals. But it would also help soldiers infiltrate — and possibly clear — occupied structures. Even if that future is still a ways off, Fitle, who's headed to Rice University in the fall, and Carte, who's going to MIT, don't plan on simply waiting for it.