Phoenix's Robotic Arm (RA) is the single most crucial element to making scientific measurements. The robotic arm combines strength and finesse to dig trenches, scrape water ice, and precisely deliver samples to other instruments on the science deck. Also, the robotic arm carries a camera and thermal-electric probe to make measurements directly in the trench.
The following table shows the relationships between Phoenix's science objectives, the scientific measurements to be made, and the instruments that will make these measurements.
SSI = Surface Stereo Imager
RAC = Robotic Arm Camera
MARDI = Mars Descent Imager
TEGA = Thermal and Evolved Gas Analyzer
MECA = Microscopy, Electrochemistry, and Conductivity Analyzer
WC = Wet Chemistry Experiment
M = Microscopy, including the Optical Microscope and the Atomic Force Microscope
TECP = Thermal and Electrical Conductivity Probe
MET = Meteorological Station