NASA’s Mars Polar Lander (MPL), designed to land near Mars' south polar cap to dig for water-ice with a robotic arm, launched today in 1999. The objective was to explore the never-before studied carbon dioxide ice cap, about 1,000 kilometers (620 miles) from the south pole. The mission also called for recording meteorological conditions, analyzing samples of polar deposits, and taking multispectral images. Unfortunately the mission was lost at the end of the year on Dec. 3, 1999 during Mars orbital insertion.

The probable cause of the loss of Mars Polar Lander was premature shutdown of the descent engines. NASA used Mars Global Surveyor to look for the lander but did not find it. Due to the premature shutdown, MPL may have crashed on the surface or may have missed being caught in Mars’ gravity and continued into space.

Someday, perhaps we will discover the rest of the story.