The narrow, 9-inch-square (20-cm) shaft ascends some 246 feet (65 meters)
from the south wall of the Queen's Chamber. At its end is a stone slab with
two copper handles. What lies beyond, nobody knows -- yet. But we may have a
better idea after the robot's exploits are beamed live from the Giza
The shafts have been subject of plenty of speculation since they were discovered in 1872. One theory is that they supplied air for workers. But if so, why were they fitted with stone seals before work was completed -- the Queen's Chamber was never finished. And why don't they have openings on the pyramid's surface? Another suggests that a secret chamber is behind the stone door.
SOUL GUIDE? An older theory called the passageways "star shafts" because they seemed to point toward the Canis Major and Orion constellations -- perhaps to help guide the Pharaoh's soul toward the heavens. But that notion was partially debunked in 1993 by Rudolf Gantenbrink, an engineer working with the German Archaeological Institute.
He sent a little robot crawling up the shafts and discovered that they bend, so they don't point at particular stars. However, that doesn't rule out the possibility they were designed as "soul shafts" to help the Pharaoh begin his afterlife journey.
Even since Gantenbrink's robot found the stone slab the end of the southern shaft, archeologists have been itching to mount a more sophisticated expedition. Egypt finally gave a go-ahead to a team led by Mark Lehner, a University of Chicago archeologist, and Zahi Hawass, National Geographic Society's explorer-in-residence and head of Egypt's antiquities council.
CEILING-HUGGER. To build the high-tech rover, National Geo tapped iRobot Corp., a Sommerville (Mass.) spin-off from Massachusetts Institute of Technology. Its creation will crawl up the shaft on tank-type treads that can grip both the floor and ceiling. When it arrives at the stone slap, it'll launch a battery of tests. A special radar system will probe for a secret room. If this indicates a hidden chamber, the robot will try to poke tiny optical-fiber video cameras through any cracks around the slab to give viewers the first peek in more than 4,500 years.
In addition, a force gauge will detect if the stone moves, and in what direction, when the robot pushes on the slab. If the door remains in place, an electric-current tester will contact the copper pins in the door handles to see if they connect to some other copper object on the reverse side. If a current flows, the length of the copper will be determined by measuring electrical resistance. And an ultrasonic system will gauge the thickness of stones along the shaft as well as the slab at the shaft's end.
Perhaps by the program's end, iRobot's little rover will answer one of the remaining mysteries about the world's largest pyramid. By Otis Port in New York