Sampling cores requires the controlled breakoff of the core at a known location with respect to the drill end. An additional problem is designing a mechanism that can be implemented at a small scale, yet is robust and versatile enough to be used for a variety of core samples.
The praying mantis that is disclosed herein is an active core breaking/retention mechanism that requires only one additional actuator other than the drilling actuator. It can break cores that are attached to the borehole bottom as well as broken cores, and it also acts as a core retention device. The cores are broken at the bottom of the sample tube with a clean cut. The invention uses a core bending principle and does not induce additional axial load on the drill/robotic arm.
This invention is potentially applicable to sample return and in situ missions to planets such as Mars and Venus, moons such as Titan and Europa, and comets. It is also applicable to terrestrial applications like forensic sampling and geological sampling in the field.
This work was done by Mircea Badescu, Stewart Sherrit, Yoseph Bar-Cohen, Xiaoqi Bao, and Randel A. Lindemann of Caltech for NASA’s Jet Propulsion Laboratory. NPO-47356
This Brief includes a Technical Support Package (TSP).

Praying Mantis Bending Core Breakoff and Retention Mechanism
(reference NPO-47356) is currently available for download from the TSP library.
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