The rover then touches down and the line is immediately cut, and the descent stage flies up and away to a safe distance from Curiosity. Safely on the surface of Mars, Curiosity powers up and makes contact with Earth, ending the 7 minutes of terror.
NASA says the span of time from atmospheric entry until touchdown is not predetermined. Exact timing and altitude for key events depends on unpredictable factors in atmospheric conditions on landing day, and the decisions will be made by the spacecraft during the descent.
The guided entry technique enables the spacecraft to respond and adapt to the atmospheric conditions it encounters more effectively than any previous Mars mission.