Today NASA announced that its Curiosity Rover has successfully collected the first sample drilled from the interior of a Martian rock and stands ready to perform the first analysis of material taken from beneath the surface of Mars.
The rover spent the past month exploring Yellowknife Bay, an area hypothesized to have once been water-rich. Curiosity conducted , and eventually its first . Scott McCloskey, drill systems engineer for the , confirmed at a press conference today that the rover now holds about a tablespoon of gray, powdered rock drilled out from a section of Martian bedrock.
Last week, using a complex combination of algorithms, sensors, and stabilizers, JPL engineers and scientists instructed Curiosity to bore a 2.5-inch-deep hole into a portion of bedrock with the rover's heavy-duty rotary-percussion drill. It created a pile of grey-colored tailings which could potentially provide scientists with a window into the Red Planet's past.
"Curiosity's first drill hole at the John Klein site is a historic moment for the MSL mission, for JPL, NASA, and the United States," said Louise Jandura, sample system chief engineer, at today's press conference. While past missions—such as the manned Apollo landings in the 60s and 70s and the Soviet Union's Venera landers in the '80s—have bored into rock formations on the Moon and Venus, Curiosity is the first mission to drill down into the martian surface. Past martian rovers Phoenix, Spirit, and Opportunity had only rock-abrasion tools, which only scratched the surface of rocks on Mars.
"Having a rock-drilling capability on a rover is a significant advancement in our ability to investigate Mars," Janudra said. "It allows us to go beyond the surface layer, unlocking a time capsule of evidence about the state of Mars going back three or four billion years." Joel Hurowitz, sampling system scientist, says that unlike surface samples, rock interiors haven't been exposed to the harsh radiation and weathering that could have destroyed the evidence of Mars' aqueous past.
The difference is evident in the stark contrast of color between the red-orange surface-level rock and the grey tailings unearthed by rover's drill, Hurowitz says. "This is something the science team is really excited about," he says. "When things turns orange, there's a rusting process going on that oxidizes the iron in the rock, so the fact that these rocks aren't that color may be telling us that these rocks didn't go through that process that usually turns things to rust."
In terms of the overall Curiosity mission, the drilling and collection of sub-surface samples was the last "shakedown" test for the rover, capping off a series of tests meant to ensure all of Curiosity's onboard equipment survived the landing and is functioning properly. "It's a real big turning point for us," says John Grotzinger, the mission's principal investigator. "With that comes more confidence, a chance at fewer surprises, and an increase in the efficiency of which we'll be able to do all of this."
These celebrations, however, come with some complications. Daniel Limoadi, lead systems engineer for surface sampling and science systems, warned of a potential problem with a loose sieve on the rover's Collection and Handling for In-Situ Martian Rock Analysis (CHIMRA) device. Based on JPL tests here on Earth, the 150-micron screen responsible for sieving samples for the rover's Chemistry and Mineralogy (CheMin) and Sample Analysis at Mars (SAM) instruments came loose on one of two CHIMRA test devices at JPL's lab. While the damaged sieve of the test model has proven to perform well into the rover's projected mission timeline and then some, scientists plan to reduce the amount of times they'll use the sieve until they determine the cause of the test-model failure.
In the next few days, scientists plan to sieve subsequent samples drilled from the same hole and then feed them into CheMin and then SAM. "We're going to take it one step at a time," Grotzinger says. "And based on that we're going to decide what to do next. The only thing I can say is we're discovery-driven."