Probe Configuration and Systems
The probes weigh less than 2 kg each. They have a squat cylindrical shape in their stowed position, on the cruise stage under the solar panels of the Mars Polar Lander. They are self-contained and have no electrical connection to the Lander. The probes are protected by an aeroshell designed to shatter on impact with the surface. On landing, the probe will separate into an aftbody which will remain on the surface and a forebody which will penetrate into the soil. The two parts are connected by a flexible cable. The aftbody is a short cylinder which contains the primary batteries, pressure sensors, and communications equipment, including an antenna. The forebody is a thin cylinder with a rounded front end. One set of thermal properties equipment, including a temperature sensor, is housed near the front of the cylinder. Above this at the center of the cylinder is a 3-axis accelerometer surrounded by the electronics and controller. Above these is another set of thermal properties equipment. Above this are the drill apparatus, soil sample chamber, and the heating and ice and water vapor detection equipment.
Technology tests include survivability of small science instruments, a non-erosive aeroshell, an ultra-low temperature lithium battery, a three-dimensional microcontroller, microelectronics with mixed digital/analog integrated circuits, and flexible interconnects for system cabling.