Deep Space 2

Deep Space 2 was a NASA New Millennium mission made of two small penetrator probes, named Amundsen and Scott after the polar explorers, that were meant to strike the surface of Mars near the south polar layered terrain and measure what lay below it. Each probe had a mass of 3.572 kilograms and was built from a ceramic aeroshell designed to shatter on impact, a slim forebody that would drive 0.3 to 1 meter into the soil carrying a small drill, a temperature sensor and a water vapor detector, and an aftbody that would stay above ground to relay data. The two probes rode to Mars on the cruise stage of the Mars Polar Lander, launched on a Delta rocket in January 1999. No signal was ever received after the planned arrival on 3 December 1999, the mission was presumed lost, and the cause of the failure is not known. Development cost about 29.2 million dollars.