Mars Aquarius Mission and Titan Explorer

The Mars Aquarius Mission is designed to carry out several scientific studies of the surface and subsurface of Mars with an emphasis on locating subterranean water. This mission is a precursor to a manned mission to Mars. A manned mission will require an extended stay on the planet's surface, and an accessible source of water will greatly simplify life support requirements. Using data from previous Mars observations, four sites were selected as possible locations of subsurface water. The Aquarius spacecraft carries one penetrator for each of these sites