Curiosity, an Astrobiologist on six wheels
Posted July 28, 2012
Astrobiology, the study of environments beyond Earth and the possibility that life may have been supportable there, is a young science. It crosses biology, astronomy and since much of it's raw data currently lies within rock and soil geology. Curiosity, the NASA rover which will arrive the morning of August 6, is uniquely equipped to help scientists determine whether or not life could have gained a foothold on Mars.
The rover was assembled in Pasadena, Calif. in a huge clean room at the Jet Propulsion Laboratory. Instruments aboard the rover came from partnerships with scientific agencies world wide including the Centro de Astrobiologica in Spain, Russian Space Agency, Canadian Space Agency. U.S. companies L-3 Cincinnati Electronics in Ohio, the Los Alamos National Laboratory, Malin Space Science Systems in San Diego, as well as NASA's Goddard Space Flight Center in Maryland and Ames Research Center at Moffet Field, Calif.
The mission is called the Mars Science Laboratory for good reason. Curiosity is an astrobiology lab on 6 wheels. The ten instruments aboard were designed with a focus on searching for evidence of habitable environments.
Sample Analysis at Mars (SAM) is a suite of instruments with the ability to measure mineralogy and organics in the rocks, soil and the atmosphere. Scientists will be using SAM to look for compounds of carbon associated with life, such as methane. Orbital studies of Mars in 2003 discovered and abundance of methane produced in the summer months.
The CheMin (Chemistry and Mineralogy) instrument focuses on minerals in rocks and soil. Understanding those minerals and the forms they take reveals the conditions in which they formed. Previous missions have indicated a very wet past for Mars. CheMin will help better understand that.
Much of the popularity of previous rovers stems from the images returned each day. Curiosity features more and better cameras than any previous mission. A total of 17 cameras are mounted throughout the nearly 2,0000 pound rover ranging from black and white hazard avoidance cameras with fish eye lenses to high definition video cameras. For the first time, NASA has equipped the rover with color cameras. Previous missions have created color photos by stacking three separate images taken with red, blue and green filters. Inclusion color cameras on this rover will not only speed the creation of images, it will also provide the most color accurate photos, matching what the human eye might one day see.
Curiosity is capable of remotely analyzing rock samples using ChemCam. What looks like a pink cyclops-like eye on the rover's mast is actually a laser which can zap rocks up to 23 feet away with more than 1 million watts of power for 5 billionths of a second. This vaporizes enough material for onboard spectrometers to identify the chemical elements in the target. This broadens the data collected by the rover and gives JPL's rover drivers a remote control tool of sorts to help determine whether "that rock over there" is worth altering the planned route to investigate.
The Mars Hand Lens Image (MAHLI) will provide close up views of minerals and textures, helping to reveal how they were formed. This kind of up close inspection matches how geologist study in the field here on Earth. Up close views reveal the texture and shapes of rocks revealing much about the conditions they've experienced. Think of the smooth stones on the bottom of a creek vs. sharp rocks breaking off the wall of cliff.
The Radiation Assessment Detector (RAD) was the first instrument activated. It has been measuring radiation as MSL has cruised and will continue to do so as it descends through the Martian atmosphere and through it's at least one year mission roving the planet's surface. The data returned by this instrument will not only provide another piece of the astrobiology puzzle, it will be valuable in planning any future human exploration of Mars. Human visitors to Mars will need sufficient radiation shielding where they live and work as will any food produced there.
The Alpha Particle X-Ray Spectrometer (APSX) is mounted on the end of Curiosity's robotic arm, along with a drill which can reach depths far beyond past missions. APSX expands on work begun by previous rovers where salty sediment on bedrock was analyzed and found to indicate ancient hot springs or steam vents. Drill bits wear out so engineers packed replacements within reach of the robotic arm.
The Dynamic Albedo of Neutrons (DANS) instrument focuses on ice and minerals. It is able to locate water and ice nearly 7 feet beneath the rover's wheels.
The Rover Environmental Monitoring Station (REMS) is a weather station. Like Earth, Mars can have high clouds, dust storms, and hurricane force winds. Mars is significantly colder than Earth with lows reaching nearly -200 degrees Fahrenheit. REMS includes instruments measuring some of the same weather data studied each day in the WRAL Weather Center including wind speed and direction, pressure, relative humidity, air and ground temperature as well as ultraviolet radiation. Measurements will be taken every 5 minutes by REMS for a Martian year (98 Earth weeks).
The primary goal of Curiosity is the search for evidence, primarily in the geologic record, that Mars was once habitable for life as we know it. Even if life doesn't exist there now, the rocks and soil both on the surface and below can be studied by the massive rover for signs of ancient habitable environments.