A sample of icy soil collected by the robotic arm of NASA’s Phoenix Mars lander is apparently stuck in its scoop, foiling efforts to analyze it. The arm picked up 3 cubic centimeters of material Friday night and lifted it over an oven designed to heat samples for analysis, mission officials said Saturday. The arm tilted its scoop, ran a tool motor to try to sprinkle the sample into the oven, and finally inverted the scoop directly over the oven’s open doors. But the science instrument, called the “Thermal and Evolved-Gas Analyzer,” detected that not enough material fell inside.