Curiosity’s mission to discover more about Mars took another step forward yesterday as a slice of Martian bedrock was drilled out using a drill bit attached to a robotic arm on the Mars exploration vehicle, reports NASA
Curiosity carried out a preparatory drill test
on February 7 using both percussion and rotation to drill about 0.8 inch (about 2 centimetres) into a rock. This produced bore fragments for assessment prior to the first drilling being made for sample collection.
The drill test was carried out on an area of flat, vein-bearing rock which NASA scientists have named ‘John Klein’ in memory of a Mars Science Laboratory deputy project manager who died in 2011. Before test drilling took place, an examination of this rock had shown some evidence of wet environmental conditions in Mars’ history.
On February 9, NASA announced
that the Mars Curiosity rover had used its robotic drill to bore into the ‘John Klein’ rock and detach a rock sample for analysis. This was another ‘first’ for the Curiosity mission. Never before has any robot explorer drilled into Martian rock to collect a sample.
The drill sample hole measures 0.63 inch (1.6cm) wide and 2.5 inches (6.4cm) deep in a patch of fine grain sedimentary bedrock. The Curiosity rover will use its onboard laboratory instrumentation to analyse samples of the rock powder taken from ‘John Klein’. Analysis of the rock sample is awaited with a considerable degree of anticipation by NASA mission scientists, given the apparent ancient wet conditions indicated by the surface of the rock.
John Grunsfeld, NASA’s associate administrator for the agency's Science Mission Directorate hailed the obtaining of the rock sample as the biggest breakthrough yet for Curiosity, saying,
“The most advanced planetary robot ever designed is now a fully operating analytical laboratory on Mars. This is the biggest milestone accomplishment for the Curiosity team since the sky-crane landing last August, another proud day for America."
‘Sorting’ of the John Klein rock sample will now take place with a series of laboratory manoeuvres over the next few days followed by portions of the sample being delivered to Curiosity’s onboard laboratory instruments for analysis.
As ever with Curiosity, further steps will be taken to ensure that samples analysed are not contaminated with any Earth residues still on Curiosity. Curiosity’s instruments were cleaned and cleaned again before leaving Earth but some of the sample material will be used as a scourer just in case any traces of Earth material remain, before analyses commence. As Scott McCloskey, drill systems engineer with JPL explained,
"We'll take the powder we acquired and swish it around to scrub the internal surfaces of the drill bit assembly. Then we'll use the arm to transfer the powder out of the drill into the scoop, which will be our first chance to see the acquired sample."
The Earth observer might think it no big deal to drill out chunklets of rocks on Mars, but, illustrating the painstaking approach adopted for the Curiosity mission, JPL's Louise Jandura, chief engineer for Curiosity's sample system, said,
"Building a tool to interact forcefully with unpredictable rocks on Mars required an ambitious development and testing program. To get to the point of making this hole in a rock on Mars, we made eight drills and bored more than 1,200 holes in 20 types of rock on Earth."
Once inside Curiosity’s sample handling device, the rock powder will be vibrated over a sieve to eliminate particles larger than six-thousandths of an inch (150 microns) across. After sieving, samples will then be transferred to Curiosity’s Chemistry and Mineralogy (CheMin
) instrument and the Sample Analysis at Mars (SAM)
instrument for sample analysis to commence.
Rock sample drilling is the latest stage in NASA's Mars Science Laboratory Project. The principle mission objective is to ascertain whether an area within Gale Crater on Mars ever offered conditions in which life might have existed.