This is the first time NASA has encountered a situation like this, and it took nearly a week to resolve. The Curiosity rover landed on Mars in August 2012. Photograph: Getty Images While it has enabled many exciting discoveries, the Curiosity Rover has also encountered its share of setbacks. The latest left NASA engineers speechless. On April 25, Curiosity drilled into a rock nicknamed “Atacama” to collect a sample. When the rover retracted the robotic arm after drilling, the entire rock unexpectedly lifted off the Martian surface—all 28.6 pounds of it. While other Curiosity drilling operations have caused cracks or breaks in the upper layers of Martian rocks during the rover's nearly 14-year mission, this is the first time one has remained stuck to the sleeve that surrounds the drill's rotating tip.…