Massing 290 kilograms with the ability to carry an additional 130 kilograms of payload, the Scarab is 1.5 meters wide, approximately 1.5 meters long, and between 1.5 and 2 meters tall. The 1 meter coring drill is the centerpiece of the vehicle. The surrounding chassis is designed to conform to the terrain and lowers itself during drilling to mute the force and torque created.
The Scarab uses laser scanners to create a three dimensional map of the surrounding terrain. This system operates equally well in daylight or darkness. The vehicle also uses a velocity camera to estimate its ground speed. This camera combines with sensors that estimate acceleration and angular momentum to provide exact positioning systems to the navigation systems.
The drill collects samples in a one meter sample tube, running all samples through a crusher that creates a powder of particles no larger than one millimeter and storing them in the payload bay until a predetermined amount is reached. The instruments inside the Scarab payload bay can analyze the samples, baking them to release gases so its component parts can be identified. The entire instrumentation panel can be removed from the payload bay, allowing it to hold extra batteries for long missions or other tools and equipment.
The Carnegie Mellon team put the Scarab through two series of extended tests in 2008. The first took place in Moses Lake, Washington in June and the second in Mauna Kea, Hawaii in October and November. Most of the tests in Washington explored the capabilities of the laser navigation system and the vehicle's mobility. The tests in Hawaii also exercised the navigation systems in a lunar-like terrain filled with volcanic ash. Drawbar tests to examine what happens when forces pull back on the Scarab were also performed as were tests of the velocity camera and drilling system.
TFOT has previously reported on the Scarab's changeable chassis design back in October of 2008. TFOT has also reported on other equipment designed for use on the moon, including a nuclear power generator designed for use on the moon, a waterless concrete that may be used to build structures on the moon, the winner of NASA's lunar lander challenge, and tests of NASA's lunar rover in Arizona.
You can read more about the Scarab at the Scarab project page hosted by the Field Robotics Center at Carnegie Mellon.