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Next Mars Rover Gets a Test Taste of Mars Conditions - 03.18.11This image shows preparation for one phase of testing of the Mars Science Laboratory rover, Curiosity. Image credit: NASA/JPL-Caltech
A space-simulation chamber at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is temporary home this month for the Curiosity rover, which will land on Mars next year.
Tests inside the 25-foot-diameter chamber (7.6-meters) are putting the rover through various sequences in environmental conditions resembling Martian surface conditions. After the chamber's large door was sealed last week, air was pumped out to near-vacuum pressure, liquid nitrogen in the walls dropped the temperature to minus 130 degrees Celsius (minus 202 degrees Fahrenheit), and a bank of powerful lamps simulated the intensity of sunshine on Mars.
Other portions of NASA's Mars Science Laboratory spacecraft, including the cruise stage, descent stage and backshell, remain in JPL's Spacecraft Assembly Facility, where Curiosity was assembled and where the rover will return after the simulation-chamber tests. In coming months, those flight system components and the rover will be shipped to NASA's Kennedy Space Center in Florida for final preparations before the launch period of Nov. 25 to Dec. 18, 2011.
The mission will use Curiosity to study one of the most intriguing places on Mars -- still to be selected from among four finalist landing-site candidates. It will study whether a selected area of Mars has offered environmental conditions favorable for microbial life and for preserving evidence about whether Martian life has existed.
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Advanced NASA Instrument Gets Close-up on Mars Rocks - 02.18.11The sensor head on the Alpha Particle X-ray Spectrometer instrument was installed during testing at NASA's Jet Propulsion Laboratory. Image credit NASA/JPL-Caltech
NASA's Mars Science Laboratory rover, Curiosity, will carry a next generation, onboard "chemical element reader" to measure the chemical ingredients in Martian rocks and soil. The instrument is one of 10 that will help the rover in its upcoming mission to determine the past and present habitability of a specific area on the Red Planet. Launch is scheduled between Nov. 25 and Dec. 18, 2011, with landing in August 2012.
The Alpha Particle X-Ray Spectrometer (APXS) instrument, designed by physics professor Ralf Gellert of the University of Guelph in Ontario, Canada, uses the power of alpha particles, or helium nuclei, and X-rays to bombard a target, causing the target to give off its own characteristic alpha particles and X-ray radiation. This radiation is "read by" an X-ray detector inside the sensor head, which reveals which elements and how much of each are in the rock or soil.
Identifying the elemental composition of lighter elements such as sodium, magnesium or aluminum, as well as heavier elements like iron, nickel or zinc, will help scientists identify the building blocks of the Martian crust. By comparing these findings with those of previous Mars rover findings, scientists can determine if any weathering has taken place since the rock formed ages ago.
All NASA Mars rovers have carried a similar instrument – Pathfinder's rover Sojourner, Spirit and Opportunity, and now Curiosity, too. Improvements have been made with each generation, but the basic design of the instrument has remained the same.
"APXS was modified for Mars Science Laboratory to be faster so it could make quicker measurements. On the Mars Exploration Rovers [Spirit and Opportunity] it took us five to 10 hours to get information that we will now collect in two to three hours," said Gellert, the intrument's principal investigator. "We hope this will help us to investigate more samples."
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NASA Mars Rover Will Check for Ingredients of Life - 01.18.11Technicians and engineers inside a clean room at NASA's Jet Propulsion Laboratory, Pasadena, Calif., prepare to install SAM into the mission's Mars rover, Curiosity. Image credit NASA/JPL-Caltech
PASADENA, Calif. -- Paul Mahaffy, the scientist in charge of the largest instrument on NASA's next Mars rover, watched through glass as clean-room workers installed it into the rover.
The specific work planned for this instrument on Mars requires more all-covering protective garb for these specialized workers than was needed for the building of NASA's earlier Mars rovers.
The instrument is Sample Analysis at Mars, or SAM, built by NASA's Goddard Space Flight Center, Greenbelt, Md. At the carefully selected landing site for the Mars rover named Curiosity, one of SAM's key jobs will be to check for carbon-containing compounds called organic molecules, which are among the building blocks of life on Earth. The clean-room suits worn by Curiosity's builders at NASA's Jet Propulsion Laboratory, Pasadena, Calif., are just part of the care being taken to keep biological material from Earth from showing up in results from SAM.
Organic chemicals consist of carbon and hydrogen and, in many cases, additional elements. They can exist without life, but life as we know it cannot exist without them. SAM can detect a fainter trace of organics and identify a wider variety of them than any instrument yet sent to Mars. It also can provide information about other ingredients of life and clues to past environments.
Researchers will use SAM and nine other science instruments on Curiosity to study whether one of the most intriguing areas on Mars has offered environmental conditions favorable for life and favorable for preserving evidence about whether life has ever existed there. NASA will launch Curiosity from Florida between Nov. 25 and Dec. 18, 2011, as part of the Mars Science Laboratory mission's spacecraft. The spacecraft will deliver the rover to the Martian surface in August 2012. The mission plan is to operate Curiosity on Mars for two years.
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NASA's Next Mars Rover to Zap Rocks With Laser - 12.22.10Researchers prepare for a test of the Chemistry and Camera (ChemCam) instrument that will fly on NASA's Mars Science Laboratory mission. Image credit NASA/JPL-Caltech/LANL
A rock-zapping laser instrument on NASA's next Mars rover has roots in a demonstration that Roger Wiens saw 13 years ago in a colleague's room at Los Alamos National Laboratory in New Mexico.
The Chemistry and Camera (ChemCam) instrument on the rover Curiosity can hit rocks with a laser powerful enough to excite a pinhead-size spot into a glowing, ionized gas. ChemCam then observes the flash through a telescope and analyzes the spectrum of light to identify the chemical elements in the target.
That information about rocks or patches of soil up to about 7 meters (23 feet) away will help the rover team survey the rover's surroundings and choose which targets to drill into, or scoop up, for additional analysis by other instruments on Curiosity. With the 10 science instruments on the rover, the team will assess whether any environments in the landing area have been favorable for microbial life and for preserving evidence about whether life existed. In late 2011, NASA will launch Curiosity and the other parts of the flight system, delivering the rover to the surface of Mars in August 2012.
Wiens, a geochemist with the U.S. Department of Energy's Los Alamos National Laboratory, serves as ChemCam's principal investigator. An American and French team that he leads proposed the instrument during NASA's 2004 open competition for participation in the Mars Science Laboratory project, whose rover has since been named Curiosity.
In 1997, while working on an idea for using lasers to investigate the moon, Wiens visited a chemistry laboratory building where a colleague, Dave Cremers, had been experimenting with a different laser technique. Cremers set up a cigar-size laser powered by a little 9-volt radio battery and pointed at a rock across the room.
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Camera on Curiosity's Arm Will Magnify Clues in Rocks - 11.16.10The Curiosity Cam live video feed allows the public to watch technicians assemble and test NASA's next Mars rover in a clean room at the Jet Propulsion Laboratory, Pasadena, Calif. Image credit NASA/JPL-CalTech
PASADENA, Calif. -- More than one million people have watched assembly and testing of NASA's next Mars rover via a live webcam since it went online in October.
NASA's Mars Science Laboratory, also known as the Curiosity rover, is being tested and assembled in a clean room at the agency's Jet Propulsion Laboratory in Pasadena, Calif. The webcam, affectionately dubbed "Curiosity Cam," shows engineers and technicians clad in head-to-toe white smocks working on the rover.
Metrics from the webcam's hosting platform, Ustream, showed more than one million unique viewers spent more than 400,000 hours watching Curiosity Cam between Oct. 21 and Nov. 23. There have been more than 2.3 million viewer sessions.
The camera is mounted in the viewing gallery of the Spacecraft Assembly Facility at JPL. While the gallery is a regular stop on JPL's public tour, Curiosity Cam allows visitors from around the world to see NASA engineers at work without traveling to Pasadena.
Viewers from Chile, Japan, Turkey, Spain, Mexico and the United Kingdom have sent good wishes and asked questions in the chat box that accompanies the Curiosity Cam webstream. At scheduled times, viewers can interact with each other and JPL staff. The chat schedule is updated weekdays at http://www.ustream.tv/nasajpl .
Months of assembly and testing remain before the car-sized rover is ready for launch from Cape Canaveral, Fla. The rover and spacecraft components will ship to NASA's Kennedy Space Center in Florida next spring. The launch will occur between Nov. 25 and Dec. 18, 2011. Curiosity will arrive on Mars in August 2012.
The rover is one of the most technologically challenging interplanetary missions ever designed. Curiosity is engineered to drive longer distances over rougher terrain than previous Mars rovers. It will carry a science payload 10 times the mass of instruments on NASA's Spirit and Opportunity rovers. Curiosity will investigate whether the landing region had environments favorable for supporting microbial life. It will also look for environments that have been favorable for preserving evidence about whether life existed.
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Spain Supplies Weather Station for Next Mars Rover - 11.30.10Sensors on two finger-like mini-booms extending horizontally from the mast of NASA's Mars rover Curiosity will monitor wind speed, wind direction and air temperature. Image credit: NASA/JPL-Caltech
The first instrument from Spain for a mission to Mars will provide daily weather reports from the Red Planet. Expect extremes.
Major goals for NASA's Mars Science Laboratory include assessing the modern environment in its landing area, as well as clues to environments billions of years ago. The environment station from Spain will fill a central role in studying modern conditions by measuring daily and seasonal changes.
The Rover Environmental Monitoring Station, or REMS, is one of 10 instruments in the mission's science payload. REMS uses sensors on the mast, on the deck and inside the body of the mission's car-size rover, Curiosity. Spain's Ministry of Science and Innovation and Spain's Center for Industrial Technology Development supplied the instrument. Components were installed on Curiosity in September and are being tested at NASA's Jet Propulsion Laboratory, Pasadena, Calif.
While most of Curiosity's electronics are sheltered for some protection from the Martian environment, the team that developed and built the environmental station needed to fashion external sensors that could tolerate the temperature extremes that some of them would be monitoring.
"That was our biggest engineering challenge," said REMS Principal Investigator Javier Gómez-Elvira, an aeronautical engineer with the Centro de Astrobiología, Madrid, Spain. "The sensors will get very cold and go through great changes in temperature every day." The Center for Astrobiology is affiliated with the Spanish National Research Council and the National Institute for Aerospace Technology.
The air temperature around the rover mast will likely drop to about minus 130 degrees Celsius (about minus 202 degrees Fahrenheit) some winter nights and climb to about minus 50 C (about minus 60 F) by 12 hours later. On warmer days, afternoon air temperatures could reach a balmy 10 to 30 C (50 to 86 F), depending on which landing site is selected.
Other challenges have included accounting for how the rover itself perturbs air movement, and keeping the entire weather station's mass to just 1.3 kilograms (2.9 pounds).
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Camera on Curiosity's Arm Will Magnify Clues in Rocks - 11.16.10The Mars Hand Lens Imager (MAHLI) camera will fly on NASA's Mars Science Laboratory mission, launching in late 2011. Image credit: NASA/JPL-Caltech/Malin Space Science Systems
NASA's next Mars rover, Curiosity, will wield an arm-mounted magnifying camera similar to one on the Mars Rover Opportunity, which promptly demonstrated its importance for reading environmental history from rocks at its landing site in 2004.
Within a few weeks after the landing, that camera at the end of Opportunity's arm revealed details of small spheres embedded in the rocks, hollows where crystals had dissolved, and fine layering shaped like smiles. These details all provided information about the site's wet past.
The camera installed on the end of Curiosity's arm this month is the Mars Hand Lens Imager, or MAHLI. Its work will include the same type of close-up inspections accomplished by the comparable camera on Opportunity, but MAHLI has significantly greater capabilities: full-color photography, adjustable focus, lights, and even video. Also, it sits on a longer arm, one that can hold MAHLI up higher than the cameras on the rover's mast. MAHLI will use those capabilities as one of 10 science instruments to study the area of Mars where NASA's Mars Science Laboratory mission lands Curiosity in August 2012.
The Mars Hand Lens Imager takes its name from the magnifying tool that every field geologist carries. Ken Edgett of Malin Space Science Systems, San Diego, is the principal investigator for the instrument. He said, "When you're out in the field and you want to get a quick idea what minerals are in a rock, you pick up the rock in one hand and hold your hand lens in the other hand. You look through the lens at the colors, the crystals, the cleavage planes: features that help you diagnose what minerals you see.
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Sensor on Mars Rover to Measure Radiation Environment - 11.09.10This instrument, shown prior to its September 2010 installation onto NASA's Mars rover Curiosity, will aid future human missions to Mars by providing information about the radiation environment on Mars and on the way to Mars. Image credit NASA/JPL-Caltech/SwRI
About eight months before the NASA rover Curiosity touches down on Mars in August 2012, the mission's science measurements will begin much closer to Earth.
The Mars Science Laboratory mission's Radiation Assessment Detector, or RAD, will monitor naturally occurring radiation that can be unhealthful if absorbed by living organisms. It will do so on the surface of Mars, where there has never before been such an instrument, as well as during the trip between Mars and Earth.
RAD's measurements on Mars will help fulfill the mission's key goals of assessing whether Curiosity's landing region on Mars has had conditions favorable for life and for preserving evidence about life. This instrument also will do an additional job. Unlike any of the nine others in this robotic mission's science payload, RAD has a special task and funding from the part of NASA that is planning human exploration beyond Earth orbit. It will aid design of human missions by reducing uncertainty about how much shielding from radiation future astronauts will need. The measurements between Earth and Mars, as well as the measurements on Mars, will serve that purpose.
"No one has fully characterized the radiation environment on the surface of another planet. If we want to send humans there, we need to do that," said RAD Principal Investigator Don Hassler of the Boulder, Colo., branch of the Southwest Research Institute.
Whether the first destination for human exploration beyond the moon is an asteroid or Mars, the travelers will need protection from the radiation environment in interplanetary space. Hassler said, "The measurements we get during the cruise from Earth to Mars will help map the distribution of radiation throughout the solar system and be useful in mission design for wherever we send astronauts."
RAD will monitor high-energy atomic and subatomic particles coming from the sun, from distant supernovas and from other sources. These particles constitute the radiation that could be harmful to any microbes near the surface of Mars or to astronauts on a Mars mission. Galactic cosmic rays, coming from supernova explosions and other events extremely far from our own solar system, are a variable shower of charged particles. In addition, the sun itself spews electrons, protons and heavier ions in "solar particle events" fed by solar flares and ejections of matter from the sun's corona. Astronauts might need to move into havens with extra shielding on an interplanetary spacecraft or on Mars during solar particle events.
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Watch Construction of NASA's New Mars Rover Live on the Web - 10.21.10The Curiosity Cam live video feed allows the public to watch technicians assemble and test NASA's next Mars rover in a clean room at the Jet Propulsion Laboratory, Pasadena, Calif. Image credit NASA/JPL-CalTech
PASADENA, Calif. -- A newly installed webcam is giving the public an opportunity to watch technicians assemble and test the next NASA Mars rover, one of the most technologically challenging interplanetary missions ever designed.
NASA's Mars Science Laboratory, also known as the Curiosity rover, is in a clean room at the agency's Jet Propulsion Laboratory in Pasadena, Calif. The webcam, affectionately called "Curiosity Cam," provides the video feed, without audio, from a viewing gallery above the clean room floor. The video will be supplemented periodically by live Web chats featuring Curiosity team members answering questions about the rover. Currently, work in the clean room begins at 8 a.m. PDT Monday through Friday.
Assembly engineers and technicians have been busy adding new avionics and instruments to the rover. Beginning Friday, viewers will see the assembly team carefully install the rover's suspension system and its six wheels. On Tuesday, the rover's 7-foot-long robotic arm will be carefully lifted and attached to the front of the rover.
Continuous live video of rover construction is available at: http://www.ustream.tv/channel/nasajpl . The feed is also available at http://www.nasa.gov/mission_pages/msl/building_curiosity.html and http://mars.jpl.nasa.gov/msl/mission/whereistherovernow/ .
The camera shows a portion of the clean room that is typically active; but the rover, spacecraft components and technicians may move out of view as work shifts to other areas of the room. When activity takes place in other testing facilities around JPL, the clean room may be empty. The camera may also be turned off periodically for maintenance or technical issues.
Months of assembly and testing remain before the car-sized rover is ready for launch from Cape Canaveral, Fla. The rover and spacecraft components will ship to NASA's Kennedy Space Center in Florida in spring of 2011. The launch will occur between Nov. 25 and Dec. 18, 2011. Curiosity will arrive on Mars in August 2012.
Curiosity is engineered to drive longer distances over rougher terrain than previous rovers with a science payload 10 times the mass of instruments on NASA's Spirit and Opportunity. The new, large rover will investigate whether the landing region has had environments favorable for supporting microbial life and for preserving evidence about whether life existed on the Red Planet.
Mobile Mars Lab Almost Ready for Curiosity Rover - 10.08.10Sample Analysis at Mars (SAM) instrument. Image Credit: NASA-GSFC
The Sample Analysis at Mars (SAM) instrument suite has completed assembly at NASA's Goddard Space Flight Center in Greenbelt, Md., and is nearly ready for a December delivery to NASA's Jet Propulsion Laboratory, Pasadena, Calif., where it will be installed into the Curiosity rover.
The Mars Science Laboratory mission will use SAM and other instruments on Curiosity to examine whether an intriguing area of Mars has had environmental conditions favorable for microbial life and favorable for preserving evidence of life, if it existed. Launch is scheduled for late 2011, with landing in August 2012.
SAM will explore molecular and elemental chemistry relevant to life. It will analyze samples of Martian rock and soil to assess carbon chemistry through a search for organic compounds, and to look for clues about planetary change.
SAM is in flight configuration, meaning its instruments are in the condition they will be in during launch and are ready to begin operations on Mars. The instrument suite (a mass spectrometer, gas chromatograph and tunable laser spectrometer) started final environmental testing this week, which includes vibration and thermal testing to ensure SAM can survive the launch, deep space flight and conditions on Mars.
Link to full press release: http://www.nasa.gov/topics/moonmars/features/sam-configure.html
PASADENA, Calif. -- The NASA Mars Science Laboratory Project's rover, Curiosity, will carry a newly delivered laser instrument named ChemCam to reveal what elements are present in rocks and soils on Mars up to 7 meters (23 feet) away from the rover.
The laser zaps a pinhead-sized area on the target, vaporizing it. A spectral analyzer then examines the flash of light produced to identify what elements are present.
The completed and tested instrument has been shipped to JPL from Los Alamos for installation onto the Curiosity rover at JPL.
ChemCam was conceived, designed and built by a U.S.-French team led by Los Alamos National Laboratory, Los Alamos, N.M.; NASA's Jet Propulsion Laboratory, Pasadena, Calif.; the Centre National d'Études Spatiales (the French national space agency); and the Centre d'Étude Spatiale des Rayonnements at the Observatoire Midi-Pyrénées, Toulouse, France.
Five Things About NASA's Mars Curiosity Rover - 09.16.10
Mars Science Laboratory, aka Curiosity, is part of NASA's Mars Exploration Program, a long-term program of robotic exploration of the Red Planet. The mission is scheduled to launch from Cape Canaveral, Fla., in late 2011, and arrive at an intriguing region of Mars in August 2012. The goal of Curiosity, a rolling laboratory, is to assess whether Mars ever had an environment capable of supporting microbial life and conditions favorable for preserving clues about life, if it existed. This will help us better understand whether life could have existed on the Red Planet and, if so, where we might look for it in the future.
Strong Robotic Arm Extends From Next Mars Rover - 09.16.10Test operators in a clean room at NASA's Jet Propulsion Laboratory, Pasadena, Calif., monitor some of the first motions by the robotic arm. Image Credit: NASA/JPL-Caltech
PASADENA, Calif. -- NASA's Mars rover Curiosity has been exercising its robotic arm since last month, when the arm was first fastened to the rover.
In the long run, watch for this long and strong arm to become the signature apparatus of NASA's Mars Science Laboratory. After landing in August 2012, the mission will rely on it for repeated research activities. One set of moves crucial to the mission's success has never been tried before on Mars: pulling pulverized samples from the interior of Martian rocks and placing them into laboratory instruments inside the rover.
Engineers and technicians are putting the arm through a range of motions this month in the clean room where Curiosity is being assembled and tested at NASA's Jet Propulsion Laboratory, Pasadena, Calif.
"We're fine-tuning the ability to make the arm go exactly where we want it to go," said JPL's Brett Kennedy, cognizant engineer for the robotic arm. "Next, we'll start pushing on things with the arm."
The arm can extend about 2.3 meters (7.5 feet) from the front of the rover body. Still to be added: the turret at the end that holds a percussive drill and other tools weighing a total of about 33 kilograms (73 pounds).
"This arm is strong, but still needs to move accurately enough to drop an aspirin tablet into a thimble," Kennedy said.
PASADENA, Calif. -- The rover Curiosity, which NASA's Mars Science Laboratory mission will place on Mars in August 2012, has been rolling over ramps in a clean room at NASA's Jet Propulsion Laboratory to test its mobility system.
Curiosity uses the same type of six-wheel, rocker-bogie suspension system as previous Mars rovers, for handling uneven terrain during drives. Its wheels are half a meter (20 inches) in diameter, twice the height of the wheels on the Spirit and Opportunity rovers currently on Mars.
Launch of the Mars Science Laboratory is scheduled for 2011 during the period from Nov. 25 to Dec. 18. The mission is designed to operate Curiosity on Mars for a full Martian year, which equals about two Earth years.
A public lecture by Mars Science Laboratory Chief Scientist John Grotzinger, of the California Institute of Technology in Pasadena, will take place at JPL on Thursday, Sept. 16, beginning at 7 p.m. PDT Time (10 p.m. EDT). Live video streaming, supplemented by a real-time web chat to take public questions, will air on Ustream at http://www.ustream.tv/channel/nasajpl .
JPL, a division of Caltech, manages the Mars Science Laboratory Project for the NASA Science Mission Directorate, Washington. More information about the mission is online at: http://mars.jpl.nasa.gov/msl/ .
While it now has a good head on its shoulders, Curiosity's "eyes" (the Mastcam), have been blindfolded in a protective silvery material. The Mastcam, containing two digital cameras, will soon be unveiled, so engineers can test its picture-taking abilities.
Up next today (July 23), the towering rover will take its first baby steps: a slow roll on the floor of the clean room where it's being built at NASA's Jet Propulsion Laboratory, Pasadena, Calif. Watch Curiosity's progress live from the clean room on Ustream until 3:30 p.m. PDT today: http://www.ustream.tv/nasajpl .
Learn more about Curiosity at: http://mars.jpl.nasa.gov/msl/ .
The wheels that will touch down on Mars in 2012 are several rotations closer to spinning on the rocky trails of Mars.
This video clip of the test shows engineers in the JPL clean room where the rover is being assembled as they put all six wheels into motion for the first time.
Engineers raised the rover just as a car mechanic would hoist a car to check the wheels, and started the "engine" to get the wheels rotating. The wheel mobility system has 10 motors in all--four for steering the rover and six for driving. During this test, all 10 motors ran in every direction. Each wheel spun forward and backwards.
Next up for Curiosity is a series of "tune-ups" to prep the rover for driving.
Learn more about Curiosity at: http://mars.jpl.nasa.gov/msl/ .
Six of them! And these wheels aren’t meant for the concrete roadways, bustling freeways, or sleepy highways—they’re destined for off-roading on Mars.
The Curiosity rover team just installed six shiny aluminum wheels on the rover, giving the rover its “legs.” Unlike previous missions that used air bags for landing on the Martian surface, Curiosity is touching down wheels first!
The rover, which is about the size of an SUV, has wheels that are 50 centimeters (20 inches) in diameter, making them bigger than a car tire. Each wheel has its own motor, giving the rover independent six-wheel drive—that’s better than an average car with two-wheel drive. But engineers didn’t stop there; the rover can swerve and turn in place a full 360 degrees.
Now, that’s cool but you may be wondering, how’s the ride? The suspension system is based on the “rocker-bogie” system, which was used on the Spirit and Opportunity rovers and the earlier Pathfinder missions. This system allows the rover to roll over large rocks and dips without tipping over. The rover can also climb steep hills, up to 45 degrees.
Did you know that the rover has something in common with World Cup soccer players? Yes, the rover wheels have “cleats,” similar to those soccer players have on their shoes. These cleats provide grip and prevent the rover from slipping while going over rocks or climbing up hills of soft sand.
With the wheels in place, Curiosity is one step closer to rolling on Mars.
Follow its journey as it embarks on one of the most exciting expeditions of our time: http://mars.jpl.nasa.gov/msl/ .
PASADENA, Calif. – NASA's next Mars rover, Curiosity, is sitting pretty on a set of spiffy new wheels that would be the envy of any car show on Earth.
The wheels and a suspension system were added this week by spacecraft technicians and engineers. These new and important touches are a key step in assembling and testing the flight system in advance of a planned 2011 launch.
Curiosity, centerpiece of NASA's Mars Science Laboratory mission, is a six-wheeler and uses a rocker-bogie suspension system like its smaller predecessors: Spirit, Opportunity and Sojourner. Each wheel has its own drive motor, and the corner wheels also have independent steering motors. Unlike earlier Mars rovers, Curiosity will also use its mobility system as a landing gear when the mission's rocket-powered descent stage lowers the rover directly onto the Martian surface on a tether in August 2012.
In coming months at NASA's Jet Propulsion Laboratory, the mobility system will get functional testing and be part of environmental testing of the rover. The mobility system will now stay on Curiosity through launch unless testing identifies a need for rework that would require it to be disassembled.
The mission will launch from Florida during the period Nov. 25 to Dec. 18, 2011. Curiosity will examine an area of Mars for modern or ancient habitable environments, including any that may have also been favorable for preserving clues about life and environment, though this mission will not seek evidence of life. It will examine rocks, soil and atmosphere with a diverse payload of tools, including a laser to vaporize patches of rock from a distance and an instrument designed to test for organic compounds.
NASA's Curiosity rover, coming together for a late 2011 launch to Mars, has a newly installed component: a key onboard X-ray instrument for helping the mission achieve its goals.
Researchers will use Curiosity in an intriguing area of Mars to search for modern or ancient habitable environments, including any that may have also been favorable for preserving clues about life and environment.
The team assembling and testing Curiosity at NASA's Jet Propulsion Laboratory, Pasadena, Calif., fastened the Chemistry and Mineralogy (CheMin) instrument inside the rover body on June 15. CheMin will identify the minerals in samples of powdered rock or soil that the rover's robotic arm will deliver to an input funnel.
"Minerals give us a record of what the environment was like at the time they were formed," said the principal investigator for CheMin, David Blake of NASA's Ames Research Center, Moffett Field, Calif. Temperature, pressure, and the chemical ingredients present -- including water -- determine what minerals form and how they are altered.
The instrument uses X-ray diffraction, a first for a mission to Mars and a more definitive method for identifying minerals than any instrument on previous missions. It supplements the diffraction measurements with X-ray fluorescence capability to garner further details of composition.
X-ray diffraction works by directing an X-ray beam at a sample and recording how the X-rays are scattered by the sample's atoms. All minerals are crystalline, and in crystalline materials, atoms are arranged in an orderly, periodic structure, causing the X-rays to be scattered at predictable angles. From those angles, researchers can deduce the spacing between planes of atoms in the crystal.
"You get a series of spacings and intensities for each mineral," Blake said. "It's more than a fingerprint because it not only provides definitive identification, but we know the reason for each pattern, right down to the atomic level."
NASA's Mars Science Laboratory mission will send Curiosity to a place on Mars where water-related minerals have been detected by Mars orbiters. The rover's 10 science instruments will examine the site's modern environment and geological clues to its past environments. NASA's multi-step strategy might include potential future missions for bringing Mars samples to Earth for detailed analysis. One key goal for the Mars Science Laboratory mission is to identify a good hunting ground for rocks that could hold biosignatures -- evidence of life -- though this mission itself will not seek evidence of life.
On Earth, life has thrived for more than 3 billion years, but preserving evidence of life from the geologically distant past requires specific, unusual conditions.
Fossil insects encased in amber or mastodon skeletons immersed in tar pits are examples of how specific environments can store a record of ancient life by isolating it from normal decomposition. But Mars won't have insects or mastodons; if Mars has had any life forms at all, they were likely microbes. Understanding what types of environments may have preserved evidence of microbial life from billions of years ago, even on Earth, is still an emerging field of study. Some factors good for life are bad for preserving biosignatures. For example, life needs water, but organic compounds, the carbon-chemical ingredients of life, generally oxidize to carbon dioxide gas if not protected from water.
Some minerals detectable by CheMin, such as phosphates, carbonates, sulfates and silica, can help preserve biosignatures. Clay minerals trap and preserve organic compounds under some conditions. Some minerals that form when salty water evaporates can encase and protect organics, too. Other minerals that CheMin could detect might also have implications about past conditions favorable to life and to preservation of biosignatures.
"We'll finally have the ability to conduct a wide-ranging inventory of the minerals for one part of Mars," said John Grotzinger of the California Institute of Technology in Pasadena, chief scientist for the Mars Science Laboratory. "This will be a big step forward. Whatever we learn about conditions for life, we'll also get a great benefit in learning about the early evolution of a planet."
Curiosity's 10 science instruments, with about 15 times more mass than the five-instrument science payload on either of the Mars rovers Spirit or Opportunity, provide complementary capabilities for meeting the mission's goals. Some will provide quicker evaluations of rocks when the rover drives to a new location, helping the science team choose which rocks to examine more thoroughly with CheMin and the Sample Analysis at Mars (SAM) experiment. SAM can identify organic compounds. Imaging information about the context and textures of rocks will augment information about the rocks' composition.
"CheMin will tell us the major minerals there without a lot of debate," said Jack Farmer of Arizona State University, Tempe, a member of the instrument's science team. "It won't necessarily reveal anything definitive about biosignatures, but it will help us select the rocks to check for organics. X-ray diffraction is the gold standard for mineralogy. Anyone who wants to determine the minerals in a rock on Earth takes it to an X-ray diffraction lab."
Blake began working 21 years ago on a compact X-ray diffraction instrument for use in planetary missions. His work with colleagues has resulted in commercial portable instruments for use in geological field work on Earth, as well as the CheMin instrument. The spinoff instruments have found innovative applications in screening for counterfeit pharmaceuticals in developing nations and analyzing archaeological finds.
CheMin is roughly a cube 25 centimeters (10 inches) on each side, weighing about 10 kilograms (22 pounds). It generates X-rays by aiming high-energy electrons at a target of cobalt, then directing the X-rays into a narrow beam. The detector is a charge-coupled device like the ones in electronic cameras, but sensitive to X-ray wavelengths and cooled to minus 60 degrees Celsius (minus 76 degrees Fahrenheit).
A sample wheel mounted between the X-ray source and detector holds 32 disc-shaped sample cells, each about the diameter of a shirt button and thickness of a business card, with transparent plastic walls. Rotating the wheel can position any cell into the X-ray beam. Five cells hold reference samples from Earth to help calibrate the instrument. The other 27 are reusable holders for Martian samples. Samples of gritty powder delivered by the robotic arm to CheMin's inlet funnel will each contain about as much material as in a baby aspirin.
Each CheMin analysis of a sample requires up to 10 hours of accumulating data while X-rays are hitting the sample. The time may be split into two or more nights of operation.
Besides X-ray diffraction, CheMin records X-ray fluorescence data from the analyzed material. X-ray fluorescence works by recording the secondary X-rays generated when the atoms in the sample are excited by the primary X-ray source. Different elements, when excited, emit fluorescent X-rays at different and characteristic energies, so this information indicates which elements are present. This compositional information will supplement similar data collected by the Alpha Particle X-ray Spectrometer on Curiosity's arm.
CheMin's team of scientists combines expertise in mineralogy, petrology, materials science, astrobiology and soil science, with experience studying terrestrial, lunar and Martian rocks.
The launch period for the Mars Science Laboratory will begin on Nov. 25, 2011, for a landing on Mars in August 2012. Blake's wish for results from the Martian rock data he's already been anticipating for more than two decades: "I hope we find something unexpected, something surprising."
Planners of NASA's next Mars mission have selected a flight schedule that will use favorable positions for two currently orbiting NASA Mars orbiters to obtain maximum information during descent and landing.
Continuing analysis of the geometry and communications options for the arrival at Mars have led planners for the Mars Science Laboratory, or Curiosity, to choose an Earth-to-Mars trajectory that schedules launch between Nov. 25 and Dec. 18, 2011. Landing will take place between Aug. 6 and Aug. 20, 2012. Due to an Earth-Mars planetary alignment, this launch period actually allows for a Mars arrival in the earlier portion of the landing dates under consideration.
"The key factor was a choice between different strategies for sending communications during the critical moments before and during touchdown," said Michael Watkins, mission manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The shorter trajectory is optimal for keeping both orbiters in view of Curiosity all the way to touchdown on the surface of Mars. The longer trajectory allows direct communication to Earth all the way to touchdown."
The simplicity of direct-to-Earth communication from Curiosity during landing has appeal to mission planners, in comparison to relying on communications relayed via NASA's Mars Odyssey, which has been orbiting Mars since 2001, and NASA's Mars Reconnaissance Orbiter, in operation since 2006. However, the direct-to-Earth option allows a communication rate equivalent to only about 1 bit per second, while the relay option allows about 8,000 bits or more per second.
Landing on Mars is always difficult, with success uncertain. After an unsuccessful attempted Mars landing in 1999 without definitive information on the cause of the mishap, NASA put a high priority on communication during subsequent Mars landings.
"It is important to capture high-quality telemetry to allow us to learn what happens during the entry, descent and landing, which is arguably the most challenging part of the mission," said Fuk Li, manager of NASA's Mars Exploration Program at JPL. "The trajectory we have selected maximizes the amount of information we will learn to mitigate any problems."
Curiosity will use several innovations during entry into the Martian atmosphere, descent and landing in order to hit a relatively small target area on the surface and set down a rover too heavy for the cushioning air bags used in earlier Mars rover landings. In a "sky-crane" maneuver during the final minute of arrival, a rocket-powered descent stage will lower Curiosity on a tether for a wheels-down landing directly onto the surface.
Even though Curiosity won't be communicating directly with Earth at touchdown, data about the landing will reach Earth promptly. Odyssey will be in view of both Earth and Curiosity, in position to immediately forward to Earth the data stream it is receiving during the touchdown. Odyssey performed this type of "bent-pipe" relay during the May 25, 2008, arrival of NASA's Phoenix Mars Lander.
Curiosity will rove extensively on Mars, carrying an analytical laboratory and other instruments to examine a carefully selected landing area. It will investigate whether conditions there have favored development of microbial life and its preservation in the rock record. Plans call for the mission to operate on Mars for a full Martian year, which is equivalent to two Earth years.
Consideration of landing sites for the mission narrowed to four finalist candidates in November 2008. The candidate sites are still being analyzed for safety and science attributes.
Curiosity is managed by JPL for NASA's Science Mission Directorate in Washington. JPL also manages the Mars Odyssey and Mars Reconnaissance Orbiter missions, in partnership with Lockheed Martin Space Systems, Denver.
More information about NASA's Mars Science Laboratory is at: http://www.nasa.gov/msl.
This spring, engineers are testing a radar system that will serve during the next landing on Mars.
Recent tests included some near Lancaster, Calif., against a backdrop of blooming California poppy fields. In those tests, a helicopter carried an engineering test model of the landing radar for NASA's Mars Science Laboratory on prescribed descent paths. The descents at different angles and from different heights simulated paths associated with specific candidate sites for the mission.
The Mars Science Laboratory mission, managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA, is in its assembly and testing phase, in advance of a launch in autumn 2011 and delivery of a rover named Curiosity to Mars in summer 2012.
During the final stage of the spacecraft's arrival at Mars in 2012, a rocket-powered descent stage will lower the rover on a tether directly to the ground. This rover is too big for the airbag-cushioned landing method used by NASA's Mars Pathfinder mission in 1997 and Mars Exploration Rover landings in 2004.
At Mars, a radar on the descent stage will track the spacecraft's decreasing distance from the surface. Additional helicopter-flown testing of the mission's radar system will include checks of whether the suspended rover might confuse the radar about the speed of descent toward the ground.
Wolfe Air Aviation, of Pasadena, Calif., is providing the helicopter and flight services for the testing by a team of JPL engineers. The engineering test radar is affixed to a gimbal mounting at the front of the helicopter, which is more often used for aerial photography.
Malin Space Science Systems Inc., San Diego, has delivered the two cameras for the Mast Camera instrument that will be the science-imaging workhorse of NASA's Mars Science Laboratory rover, to be launched next year. The instrument, called Mastcam, has been tested and is ready for installation onto the rover, named Curiosity, which is being built at NASA's Jet Propulsion Laboratory, Pasadena, Calif.
The two component cameras have different fixed focal lengths: 34 millimeters and 100 millimeters (telephoto) and can provide high-definition color video. NASA is also providing funds for Malin to build an alternative version with zoom lenses on both cameras, in collaboration with movie producer James Cameron, a member of the Mastcam team. If the zoom pair can be completed in time for rover assembly and testing, the fixed-focal-length pair could be swapped out for them. Malin has also delivered the Mars Hand Lens Imager and the Mars Descent Imager for the Mars Science Laboratory.
For more information, see Malin Space Science Systems news release: http://www.msss.com/press_releases/mast_delivery/.