Sample Manipulation System
The Sample Manipulation System (SMS) solves a core challenge of next-generation planetary exploration: how to analyze samples for water, organics and resources with multiple remote instruments when humans are millions of kilometers away. The SMS is at the heart of the Sample Analysis at Mars (SAM) instrument suite, the core science payload of the $2.5 billion Mars Science Laboratory. SAM uses a suite of three instruments to analyze Mars for organic compounds and to determine the habitability of the planet.
To physically bring samples from Mars to the instruments in SAM, Honeybee designed the SMS as a robotic laboratory assistant. Honeybee delivered SMS to NASA Goddard Space Flight Center in 2008, and unit has performed flawlessly since the landing of the Mars Science Laboratory in 2012.
The SMS is a unique robotic system developed to pack 74 sample cups in a highly reliable, fault tolerant manner while conforming to tight constraints on control complexity, mass, volume and power (less than 6 watts continuous and 18 watts peak power). During operations, SMS receives a sample of dirt or rock powder from the robotic scoop or drill and moves it to a pyrolysis oven. Gasses from the heated samples are plumbed to the analytical suite. The SMS must position cups within 0.71mm true position at multiple interfaces of the instrumentation, and the SMS applies a precisely controlled force of up to 1350 Newtons (over 300lbs) to create a hermetic seal between the sample cup and the oven.
Mechanically, SMS is an under-actuated three degree of freedom (DOF) robotic system. Two rotational DOFs are provided by the Center Hub Actuator, which both positions a given sample cup at a specific instrument station and positions the Elevator Actuator below that cup. Then, the Elevator Actuator (third DOF) raises and lowers the sample cup into the oven. Using a single actuator for two functions required more than 360° of rotation of the center hub. A twist capsule transfers power and signals to the elevator actuator and feedback switches, allowing for 693° of rotation.