This artist's concept shows the Curiosity rover using its Chemistry and Camera, or ChemCam, instrument to investigate the composition of a rock surface. ChemCam fires invisible laser pulses at a target, which is simulated with a gray line. The instrument then views the resulting spark with a telescope and spectrometers to identify the chemical elements. (NASA/JPL illustration) › View Larger Image
Mars is More Than Just a Curiosity
An important day for NASA is drawing ever closer as the Mars Science Laboratory carrying its Curiosity rover rockets to Earth's nearest planetary neighbor.
Z. Nagin Cox, a systems engineer at NASA's Jet Propulsion Laboratory in Pasadena, Calif., outlined the mission of the Mars Science Laboratory, or MSL, and its Curiosity Rover during a colloquium presentation at Dryden May 31. Formerly deputy chief of the JPL team that developed the Mars Exploration Rovers, Spirit and Opportunity, Cox currently is a member of the Mars Science Laboratory operations team.
MSL was launched from Earth on Nov. 26, 2011, and is expected to deploy the Curiosity rover onto the Martian surface on the evening of Aug. 5, 2012. Curiosity's landing site is near the base of a mountain inside Gale Crater, near the Martian equator. Researchers plan to use Curiosity to study layers in the mountain that could provide evidence about whether Mars had a wet environment in its early years and could have supported microbial life.
Cox recalled the landing of the Spirit rover on Jan. 3, 2004, which was the first successful Mars mission since the Mars Pathfinder in 1997.
"We were already tired from working around the clock for three years. It was a high-pressure landing, as three of the previous four missions to Mars failed. The British Beagle rover that was to land on Mars on Christmas Day failed," she recalled.
Anxious moments passed in the JPL control room as the team waited to hear a series of tones transmitted from the rover that indicated its progress, she related.
Initially, tones were received that verified that certain tasks were complete. Then, there was nothing. Five minutes of silence passed since tones from the rover were last received. Then 10 minutes elapsed with no communication. At 15 minutes - still silence. Each minute was excruciating, seeming like an eternity, Cox recounted.
At minute 17, the signal came that the rover was fine and images of the planet came a few hours later.
But even with the spectacular success of the Mars Exploration Rovers, "We are not even out of the driveway," Cox said, equating the mission to those of Earth exploration during the 14th and 15th centuries.
While the Spirit and Opportunity rovers are robotic geologists, the Curiosity rover is more of a robotic chemist, she said. Curiosity is about five times larger than the earlier Mars Exploration Rovers and carries more than 10 times the weight of scientific instruments. The 1,980-pound vehicle is about the size of a small sport utility vehicle.
Included are 17 cameras, a laser to study areas to determine if they are worthy of further study, a chemistry lab, a drill, extra drill bits, radiation scanners and the related equipment deemed most important for a successful mission. This new rover also has the autonomy to use terrain assessment tools to determine the best route to areas pinpointed for scientific exploration.
Curiosity has steerable parachutes that are expected to allow for a more targeted landing. Curiosity will not use the airbag system used by the previous rovers, because of its much larger size. It will use a suspended "skycrane" system that is expected to allow it to land on its wheels. Although the mission is scheduled for two years, Cox said mission engineers expect the rover to have enough power-generation capability to enable it to function for up to 14 years.
While a sample return mission is still too complex for near-term exploration, Cox said work is under way now to plot future Mars missions.
Many people see Mars in the night sky and it is the closest of the planets to Earth. That's one reason for both casual and scientific interest. NASA began studying Mars with study of the planet's weather, sand dunes and polar caps in 1976 with the Viking mission. The Mars Pathfinder continued Mars studies when the small Sojourner rover landed in 1997, followed by the Mars Exploration Rovers that launched in mid-2003 and landed in January 2004.
NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, designed and built Curiosity and manages the Mars Science Laboratory Project for the NASA Science Mission Directorate.
By Jay Levine