Approaching Mars at over 13,000 mph, the descent only slows to around 1000 mph after entering Mars’ atmosphere, at which point a 100 lb parachute will deploy, slowing the rover to around 370 mph, a little over half the speed of sound. At these speeds, the parachute must be able to withstand over 65,000 lbs of force.
At which point the real work of the landing happens, where rockets fire in a variety of directions to both divert the rover away from the parachute while also keeping it from smashing itself against the rocky Martian soil. Eventually, the rover will land at 0 mph, completing its incredible journey from earth, and resting on the surface of another planet. (Incidentally, the distance between Earth and Mars varies between 36 and 250 million miles.)
The entire “EDL” (Entry, Descent, Landing) from entry into the thin Martian Atmosphere to landing on the now-familiar red soil–takes 7 minutes, and for that entire 7 minute period, everything must go off without a hitch.
See our slowly growing pinterest page for an infographic that breaks it all down further.