digging in a different trench phoenix ' s robotic arm connected with a hard surface that has been excited about the anticipation of next uncovering an oxide layered . " we have cut a trench and uncovered a hard layer at the same width as the freezing sheet in our other trench , " said washington university unmanned hand investigator for phoenix , ray arvidson . the arm tried at least three time to pierce the structure , but was unsuccessful . as a result the side moved into a holding cycle , awaiting its next commanded .
A robotic arm has been used for scientific discoveries.