As Mars Rover Curiosity prepared to drill into a rock called "John Klein" by NASA, scientists tested the ground pressure of the drill at the end of the rover's arm. Most recently they activated its pneumatic function to hammer a cut into the target.
Before attempting to drill into the rock, scientists must determine whether the drill will behave as they have calculated it will. Since Mars has significantly less gravity than Earth, the amount of pressure exerted when the drill is pressed against and into the rock must be measured to avoid breaking the equipment, or getting it stuck. In short, the hydraulic strength of Curiosity remains the same, on Earth or on Mars, but its effect is magnified on Mars because of the lesser gravity. Scientists must know by how much in order to determine how much to modify the default strength of the rover.
A few days ago, Mars Rover Curiosity's drill was pressed against the rock at various loads, and measured results were evaluated against calculated expectations.
Curiosity drill head pressed against Martian rock - Drill bit head on
On February 3, the bit was placed against the rock and the drill's pneumatic function was activated to test the hardness of the rock and the effectiveness of the bit. A triangular slot was hammered into the rock's surface, demonstrating that the drill could effectively penetrate the material of which the rock is made.
Scar made by drill bit hammered into rock.
A primary purpose of Curiosity's mission is to determine whether conditions that could support life were present on the planet in the distant past. One indicator is evidence of liquid water at the surface and within rocks. The rock selected for drilling in the near future shows veining that appears to have come from the deposition of minerals by liquid water moving over and through the rock. The drill can penetrate about an inch (2.5 cm). It is important to obtain samples from the interior of rocks, because the interiors have not been modified by exposure to weather, sand erosion or other external factors (a process called weathering).
In a few days, Curiosity's first drill samples will be analyzed for mineral content and other evidence of water contact in the distant past. Evidence is mounting that water contact in the Gale Crater Landing Site was common and extensive eons ago.