The Clamshell mechanism, with one quick action, acquires and retains a sample from a small body surface while minimizing sampling energy. The sampler has two quarter-sphere buckets that are driven into the small body surface. One mechanism drives a linkage that causes the two buckets to rotate about a common axis to close the buckets into each other. A benefit of this design is that one action with one actuator is used to acquire and retain the sample. Thin blades result in minimum sampling energy.

The clamshell sampler design incorporates one mechanism that drives a linkage that causes the two buckets to rotate about a common axis to close the buckets into each other.
The NASA Decadal Survey identified a Comet Surface Sample Return (CSSR) as a high-priority mission for the next decade.

This innovation was developed as a candidate tool for a potential CSSR mission with a Touch-and-Go (TAG) mission architecture. In a TAG mission, a spacecraft maneuvers within several meters of the surface of a small body, and then extends a robotic arm upon which the sampling tool is located. The arm deploys the tool to the surface, and a sample is acquired in a few seconds. Then the spacecraft thrusts away from the surface of the small body.

Some of the preliminary CSSR requirements include returning a single ≥500-cm3 sample from the surface of any comet nucleus, preserving sample complex organics (sample using a “soft” technique), and preventing aqueous alteration of the sample at any time (maintain at ≤– 10 °C). The mission also could include capturing evolved gases from the sample, returning material from a depth >10 cm, and maintaining sample stratigraphy.

This work was done by Phillip E. Walkemeyer, Anthony J. Ganino, and Paul G. Backes of Caltech for NASA’s Jet Propulsion Laboratory. NASA is seeking partners to further develop this technology through joint cooperative research and development. For more information about this technology and to explore opportunities, please contact Dan Broderick at This email address is being protected from spambots. You need JavaScript enabled to view it.. NPO-49584

NASA Tech Briefs Magazine

This article first appeared in the May, 2016 issue of NASA Tech Briefs Magazine.

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