Curiosity (rover) counted. Previous NASA Mars rovers became active only after the successful entry, descent and landing on the Martian surface. "Curiosity", on the other hand, was active when it touched down on the surface of Mars, employing the rover suspension system for the final set-down. "Curiosity" transformed from its stowed flight configuration to a landing configuration while the MSL spacecraft simultaneously lowered it beneath the spacecraft descent stage with a tether from the "sky crane" system to a soft landing—wheels down—on the surface of Mars. After the rover touched down it waited 2 seconds to confirm that it was on solid
Spirit (rover) soil. This was not the first of the mission's "embedding events" and for the following eight months NASA carefully analyzed the situation, running Earth-based theoretical and practical simulations, and finally programming the rover to make extrication drives in an attempt to free itself. These efforts continued until January 26, 2010 when NASA officials announced that the rover was likely irrecoverably obstructed by its location in soft soil, though it continued to perform scientific research from its current location. The rover continued in a stationary science platform role until communication with "Spirit" stopped on March 22, 2010 (sol ). JPL continued