Classification: Penetrator spacecraft.
Mission: Analyze Martian subsurface environment.
Features: Micro-instruments in the lower spacecraft (forebody) collect a sample of soil and analyze it for water content. Data from the forebody is sent through a flexible cable to the upper spacecraft (aftbody) at the surface; a telecommunications system on the aftbody relays data to the Mars Global Surveyor Spacecraft, operating in orbit on its mapping mission.
The Deep Space 2 probes were designed to use only an aeroshell. By eliminating parachutes and rockets, the probes are lighter and less expensive, but also very hardy. Similar in weight to a lap-top computer, they were designed to survive a high-speed impact, and to operate successfully in extremely low temperatures, something conventional miniaturized electronics, and standard spacecraft, could never do.
The two miniature probes, carrying ten experimental technologies each, piggybacked to the red planet with the Mars Polar Lander. They were to slam into Martian soil December 3, 1999. No communication was ever received from them, nor from the Mars Polar Lander.
Stabilization: Spin stabilized during cruise.
See also: DS2 Project website