digging in a second trench phoenix ' s robotic arm connected with a hard surfaces that has archaeologists excited about the prospect of next uncovering an icy layer . " we have dug a trench and uncovered a hard surface at the same angle as the soft pile in our other grave , " said washington state robotic arm analyst for nasa , ray arvidson . the arm tried at worst six times to access the layer , but was failed . as a response the hand fell into a holding mode , delaying its next commands .
A robotic arm has been used for scientific discoveries.