I am involved in several planetary missions. I am the former project scientist for the Mars Science Laboratory (MSL) mission, which is a rover the size of a small car that launched in November 2011 and landed in Gale crater on Mars on August 5, 2012 (PDT). I was also participating scientist for the Mars Exploration Rovers and for the HiRISE camera onboard the Mars Reconnaissance Orbiter. I am currently a team member for the Mars 2020 mission.
A long-standing goal of Mars environmental studies has been to understand the role of water throughout its geologic history. The presence of water is a strong indicator of potential habitability as well as of formerly different climatic conditions. Prior to studies by the Mars Exploration Rovers, most studies of water-related processes had been based on analysis of geomorphic attributes. However, we can now examine the record of past surface processes, including the role of water, through sedimentologic studies of the stratigraphic record of Mars. Many processes that operate at a planetary surface have the potential to create a record of sedimentary rocks. Sedimentary rocks can provide clues that allow past environmental conditions to be reconstructed. Therefore, the detection of sediment transport by water and wind in ancient sedimentary layers is important, because it provides insight into past climatic regimes and potential habitability.
The Mars Science Laboratory Curiosity rover launched on Saturday, November 26th at 10:02 am EST on-board an Atlas V-541 rocket from Cape Canaveral, Florida. The cruise stage successfully separated from the rocket and the rover landed on Mars on August 5, 2012. Curiosity's mission is to determine the planet's habitability and has been doing this by using a suite a sophisticated instruments including cameras, spectrometers, environmental sensors, sample-collection tools, and laboratory-quality geochemical instruments.
Entry, descent, and landing utilized a sky crane touchdown system. Due to the large size of the rover (900 kg), it could not use airbags like the Mars Exploration Rovers. The sky crane system placed the rover on its wheels, ready to begin surface operations. An animation of the landing can be found here.
The rover landed in northwestern Gale Crater, which is a 154 km diameter crater with a central mountain of sedimentary strata over 5 km high. The lower portion is made up of interbedded sulfates and phyllosilicates, suggesting that deposition occurred during changing environmental conditions. The Gale mound may be the surviving remnant of an extensive sequence of deposits observed over a widespread region. Exploring detailed stratigraphy of the lower mound is helping address MSL's overall goal of searching for habitable environments on Mars.
Curiosity successfully completed its primary mission in 2014, and celebrated its 10th anniversary in 2022. The rover has drilled 36 holes so far, traveled 30 km, and has had over 700 meters of elevation gain. In the first years of operations, Curiosity traversed over stream-rounded pebbles to a site where mud accumulated from an ancient lake. The mudstones drilled and analyzed yielded evidence for long-lived fresh water, the major elemental building blocks of life, and a source of chemical energy capable of sustaining microbial life.
Curiosity continues its traverse up the higher and younger strata of Mt. Sharp to study ancient environmental transitions and to identify habitable environments capable of preserving organic compounds. Recent findings and mission updates can be found here.
The Mars 2020 Perseverance Rover launched from Cape Canaveral, Florida on July 30, 2020 and landed in Jezero Crater, Mars on February 18, 2021. Jezero was chosen as the landing site due to its potential astrobiological implications. Carbonates line the inner rim of the crater, which, if they are anything like preserved carbonates on Earth, could preserve microorganism remains, assuming life ever originated on Mars. Mars 2020 is searching for signs of past microbial life by taking rock core samples. These core samples will be stored in metal tubes on the Martian surface until further missions can return them to Earth. 18 samples have been collected so far. More information on the mission can be found here.