This scene shows a pallet lander carrying the Mars Science Laboratory. The important thing about this graphic are the "zeros" in each number. That's because when the lander first hits the Martian atmosphere it's traveling at 12,000 mph and in each successive step there is one less zero until it lands at a gentle 12 mph. The spacecraft slows down by a factor of 10 in each step.

This all has to take place in approx. 6 minutes, from 12,000 mph to only 12 mph and it's an enormous engineering challenge.