•The Curiosity rover acquired and examined its first in-situ sample at the Rocknest deposit.•Partial use of this material was to demonstrate organic cleanliness of the sampling hardware.•First time engineering activities of the MSL sampling (SA/SPaH) hardware were accomplished. During its 57th through 100th martian days (sols) in Gale Crater, the Mars Science Laboratory (MSL) Curiosity rover performed its first sample acquisition and processing of solid, granular sample. Samples were extracted from an aeolian sand deposit at a location called Rocknest. The Rocknest sampling site was identified to fit the prelaunch scientific and engineering requirements for this first time activity. Collected material was processed and delivered to two analytical instruments, Chemistry and Mineralogy (CheMin) and Sample Analysis at Mars (SAM), that both require delivery of a specific particle size range so that they can perform analyses to determine sample mineralogy and geochemistry. The choice of an aeolian sand deposit was based on requirements to ingest non-lithified, particulate sample for decontamination of the Sample Acquisition/Sample Processing and Handling (SA/SPaH) hardware, as well as to provide an opportunity to compare analytical results to aeolian deposits from elsewhere on the martian surface.