WASHINGTON — Mars Curiosity is about to take its first sip of the red planet's sand. But only after NASA's rover plays bartender to make sure the dry dust is shaken, not stirred.
The rover's scoop will dig into the sand Saturday. Then the action starts. The end of the rover's 220-pound arm will shake "at a nice tooth-rattling vibration level" for eight hours, like a Martian martini mixer gone mad, said mission sampling chief Daniel Limonadi said.
"It kind of looks and feels like if you open the hood of your car with the engine running," Limonadi said, making engine noises in a Thursday NASA telephone press conference.
That heavy shaking will vibrate the fine dust grains through the rover chemical testing system to cleanse it of unwanted residual Earth grease. That's important for the sensitive scientific instruments that are the keystone to the $2.5 billion mission that launched last year.
The rover landed in August and has traveled three-tenths of a mile, taking pictures and analyzing the Martian air.
For the next week or two, Curiosity will scoop, shake and dump sand out three times, like a robotic version of cleaning its mouth out with mouthwash, Limonadi said. The fourth time, the rover will slowly pour "a half a baby aspirin pill of material" into the mobile lab to start a complex chemical analysis, he said.
There's nothing that seems special about the sand that will be tested and that's why NASA picked it out. It's good to start with "boring safe Martian sand dune," Limonadi said.
The car-sized rover has a complex chemical lab, a scoop and a drill to look for the basic ingredients of life, including carbon-based compounds, nitrogen, phosphorus, sulfur and oxygen. This will be the first time the chemistry lab will be used. In about a month, after going to a newer more interesting location, the rover will start drilling into the ground for samples.
NASA RELEASE BELOW:
PASADENA, Calif. -- NASA's Curiosity rover is in a position on Mars where scientists and engineers can begin preparing the rover to take its first scoop of soil for analysis.
Curiosity is the centerpiece of the two-year Mars Science Laboratory mission. The rover's ability to put soil samples into analytical instruments is central to assessing whether its present location on Mars, called Gale Crater, ever offered environmental conditions favorable for microbial life. Mineral analysis can reveal past environmental conditions. Chemical analysis can check for ingredients necessary for life.
"We now have reached an important phase that will get the first solid samples into the analytical instruments in about two weeks," said Mission Manager Michael Watkins of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Curiosity has been so well-behaved that we have made great progress during the first two months of the mission."
The rover's preparatory operations will involve testing its robotic scooping capabilities to collect and process soil samples. Later, it also will use a hammering drill to collect powdered samples from rocks. To begin preparations for a first scoop, the rover used one of its wheels Wednesday to scuff the soil to expose fresh material.
Next, the rover twice will scoop up some soil, shake it thoroughly inside the sample-processing chambers to scrub the internal surfaces, then discard the sample. Curiosity will scoop and shake a third measure of soil and place it in an observation tray for inspection by cameras mounted on the rover's mast. A portion of the third sample will be delivered to the mineral-identifying chemistry and mineralogy (CheMin) instrument inside the rover. From a fourth scoopful, samples will be delivered to both CheMin and to the sample analysis at Mars (SAM) instrument, which identifies chemical ingredients.
"We're going to take a close look at the particle size distribution in the soil here to be sure it's what we want," said Daniel Limonadi of JPL, lead systems engineer for Curiosity's surface sampling and science system. "We are being very careful with this first time using the scoop on Mars."
The rinse-and-discard cycles serve a quality-assurance purpose similar to a common practice in geochemical laboratory analysis on Earth.
"It is standard to run a split of your sample through first and dump it out, to clean out any residue from a previous sample," said JPL's Joel Hurowitz, a sampling system scientist on the Curiosity team. "We want to be sure the first sample we analyze is unambiguously Martian, so we take these steps to remove any residual material from Earth that might be on the walls of our sample handling system."
Rocknest is the name of the area of soil Curiosity will test and analyze. The rover pulled up to the windblown, sandy and dusty location Oct. 2. The Rocknest patch is about 8 feet by 16 feet (2.5 meters by 5 meters). The area provides plenty of area for scooping several times. Diverse rocks nearby provide targets for investigation with the instruments
on Curiosity's mast during the weeks the rover is stationed at Rocknest for this first scooping campaign.
Curiosity's motorized, clamshell-shaped scoop is 1.8 inches (4.5 centimeters) wide, 2.8 inches (7 centimeters) long, and can sample to a depth of about 1.4 inches (3.5 centimeters). It is part of the collection and handling Martian rock analysis (CHIMRA) device on a turret of tools at the end of the rover's arm. CHIMRA also includes a series of chambers and labyrinths for sorting, sieving and portioning samples collected by the scoop or by the arm's percussive drill.
Following the work at Rocknest, the rover team plans to drive Curiosity about 100 yards (about 100 meters) eastward into the Glenelg area and select a rock as the first target for use of its drill.
JPL, a division of the California Institute of Technology, manages the Mars Science Laboratory Project and built Curiosity.