Mars Science Laboratory
Nov. 26, 2011, 7:02 a.m. PST (10:02 a.m. EST)
Aug. 5, 2012, 10:32 p.m. PDT (Aug. 6, 2012, 1:32 a.m. EDT)
Building on the success of the two rover geologists that arrived at Mars in January, 2004, NASA's next rover mission, the Mars Science Laboratory, carrying the Curiosity rover, arrived at Gale Crater on Mars at 10:32 p.m. PDT on Aug. 5, 2012 (1:32 a.m. EDT on Aug. 6, 2012). Twice as long and three times as heavy as the Mars Exploration Rovers Spirit and Opportunity, the Mars Science Laboratory will collect Martian soil and rock samples and analyze them for organic compounds and environmental conditions that could have supported microbial life now or in the past. The mission has a truly international flavor, with a neutron-based hydrogen detector for locating water provided by the Russian Federal Space Agency, a meteorological package provided by the Spanish Ministry of Education and Science, and a spectrometer provided by the Canadian Space Agency, among others.
Mars Science Laboratory is the first planetary mission to use precision landing techniques, steering itself toward the Martian surface similar to the way the space shuttle controls its entry through the Earth's upper atmosphere. In this way, the spacecraft flew to a desired location above the surface of Mars before deploying its parachute for the final landing. In the final minutes before touchdown, the spacecraft activated its parachute and retro rockets before lowering the rover package to the surface on a tether (similar to the way a skycrane helicopter moves a large object). This landing method enabled the rover to land in an area approximately 4 miles wide and 12 miles long (7 kilometers by 20 kilometers), about one-third the size of the landing ellipses for Mars rovers that landed in 2004.
Like the twin rovers, Spirit and Opportunity, Mars Science Laboratory rover, Curiosity, has six wheels and has cameras mounted on a mast. Unlike the twin rovers, it carries a laser for vaporizing a thin layer from the surface of a rock and analyzing the elemental composition of the underlying materials. It is able to collect rock and soil samples and distribute them to on-board test chambers for chemical analysis. Curiosity carries a suite of scientific instruments for identifying carbon-containing compounds called organic molecules. Organic molecules contain one or more carbon atoms bound to hydrogen and, in many cases, additional elements. They can exist without life, but life as we know it cannot exist without them, so their presence would be an important plus for habitability. Curiosity will also check for other chemical elements important for life, such as nitrogen, phosphorus, sulfur and oxygen.
Using these tools, the rover will analyze samples scooped from the soil and drilled from rocks. The record of the planet's climate and geology is essentially "written in the rocks and soil" -- in their formation, structure, and chemical composition. The rover's onboard laboratory will study rocks, soils, and the local geologic setting in order to detect chemical building blocks of life (e.g., forms of carbon) on Mars and will assess what the Martian environment was like in the past.
NASA selected a landing site, Gale Crater, on the basis of highly detailed images sent to Earth by the Mars Reconnaissance Orbiter, in addition to data from earlier missions. The rover carries a radioisotope power system that generates electricity from the heat of plutonium's radioactive decay. This power source gives the mission an operating lifespan on Mars' surface of a full Martian year (687 Earth days) or more while also providing significantly greater mobility and operational flexibility, enhanced science payload capability, and exploration of a much larger range of latitudes and altitudes than was possible on previous missions to Mars.