The Perseverance rover will attempt to touch down in one piece on Thursday. Here’s what you need to know.

About 80 seconds after entering the atmosphere, the spacecraft experiences peak temperatures, with the heat shield on the bottom of the capsule reaching 2,370 degrees Fahrenheit. Inside the capsule, its a lot less toasty about room temperature. As the air becomes denser, the spacecraft continues to slow.
Small thrusters on the top of the capsule fire to tweak the angle and direction of its descent and keep it on course toward its landing site.
At an altitude of about seven miles, four minutes after entry into the atmosphere, the capsule is traveling at a speed under 1,000 miles per hour. It then deploys a huge parachute, more than 70 feet in diameter.
The spacecraft now drops the heat shield, allowing cameras and other instruments to take note of the terrain below to determine its position.
Even with the huge parachute, the spacecraft is still falling at about 200 miles per hour.
The next crucial step is called the sky crane maneuver. The top of the capsule, called the backshell, is let go and is carried away by the parachute. There are two pieces of the spacecraft left. The top is the descent stage in essence a rocket-powered jetpack carrying the rover beneath it. The engines of the descent stage fire, first steering to avoid a collision with the backshell and the parachute. Then the engines slow the descent to less than two miles per hour.