Mars Science Laboratory Mars Science Laboratory Mars Science Laboratory (MSL) is a robotic space probe mission to Mars launched by NASA on November 26, 2011, which successfully landed "Curiosity", a Mars rover, in Gale Crater on August 6, 2012. The overall objectives include investigating Mars' habitability, studying its climate and geology, and collecting data for a manned mission to Mars. The rover carries a variety of scientific instruments designed by an international team. MSL successfully carried out the most accurate Martian landing of any known spacecraft, hitting a small target landing ellipse of only , in the Aeolis Palus region of Gale Crater.
Chronology of discoveries of water on Mars continues to provide scientific discovery. The Spirit rover landed in what was thought to be a huge lake bed. However, the lake bed had been covered over with lava flows, so evidence of past water was initially hard to detect. As the mission progressed and the Rover continued to move along the surface more and more clues to past water were found. On March 5, 2004, NASA announced that "Spirit" had found hints of water history on Mars in a rock dubbed "Humphrey". Raymond Arvidson, the McDonnell University Professor and chair of Earth and planetary sciences at Washington University in