So very, very cool.

Just the headline alone ("NASA tests shape-shifting robot pyramid for nanotech swarms") is an eyecatcher, but the article is even more fascinating.

The robot is called "TETwalker" for tetrahedral walker, because it resembles a tetrahedron (a pyramid with 3 sides and a base). In the prototype, electric motors are located at the corners of the pyramid called nodes. The nodes are connected to struts which form the sides of the pyramid. The struts telescope like the legs of a camera tripod, and the motors expand and retract the struts. This allows the pyramid to move: changing the length of its sides alters the pyramid's center of gravity, causing it to topple over. The nodes also pivot, giving the robot great flexibility.

In January 2005, the prototype was shipped to McMurdo station in Antarctica to test it under harsh conditions more like those on Mars. The test indicated some modifications will increase its performance; for example, placing the motors in the middle of the struts rather than at the nodes will simplify the design of the nodes and increase their reliability.

The team anticipates TETwalkers can be made much smaller by replacing their motors with Micro- and Nano-Electro-Mechanical Systems. Replacement of the struts with metal tape or carbon nanotubes will not only reduce the size of the robots, it will also greatly increase the number that can be packed into a rocket because tape and nanotube struts are fully retractable, allowing the pyramid to shrink to the point where all its nodes touch.

These miniature TETwalkers, when joined together in "swarms," will have great advantages over current systems. The swarm has abundant flexibility so it can change its shape to accomplish highly diverse goals. For example, while traveling through a planet's atmosphere, the swarm might flatten itself to form an aerodynamic shield. Upon landing, it can shift its shape to form a snake-like swarm and slither away over difficult terrain. If it finds something interesting, it can grow an antenna and transmit data to Earth. Highly-collapsible material can also be strung between nodes for temperature control or to create a deployable solar sail.

Additionally, the nodes will be designed to disconnect and reconnect to different struts. If a meteoroid or rough landing punches a hole in the swarm, the system can heal itself by rejoining undamaged nodes. "Spacecraft are so expensive because failure in a single component can cripple the entire spacecraft, so extensive testing and redundant systems are employed to reduce the chance of catastrophic failure. We wouldn't live long if our bodies worked like this. Instead, when we get hurt, new cells replace the damaged ones. In a similar way, undamaged units in a swarm will join together, allowing it to tolerate extensive damage and still carry out its mission," said Curtis.

Of course, this is probably the first step on the road to the Matrix, but it will nonetheless be pretty interesting in these years before we're enslaved, lobotomized, and milked for our bioenergy.