This video is from an interview on NPR with NASA engineer Adam Steltzner, the team leader for EDL (Entry, Descent and Landing). It’s a great read, and I highly recommend you check that out in its entirety.
It’s called the seven minutes of terror. In just seven minutes, NASA’s latest mission to Mars, a new six-wheeled rover called Curiosity, must go from 13,000 mph as it enters the Martian atmosphere to a dead stop on the surface.
During those seven minutes, the rover is on its own. Earth is too far away for radio signals to make it to Mars in time for ground controllers to do anything. Everything in the system known as EDL must work perfectly, or Curiosity will not so much land as go splat.