Reentry into Earth's atmosphere should begin at 7:53 p.m. ET, according to NASA's timeline for landing day.Twenty-four seconds after reentry begins, and some 1,950 miles from splashdown, heating across the Orion capsule's 16.5-foot heat shield will build to the point that electrically charged plasma will engulf the spacecraft, preventing normal communications.

One minute and 22 seconds into the descent, temperatures across the heat shield will reach a peak of some 5,000 degrees Fahrenheit — half as hot as the visible surface of the sun.

The communications blackout is expected to end after about six minutes.

At that point, the spacecraft will be descending at about 9,000 mph, less than 200 miles from the targeted splashdown point. Eight minutes after entry, the Orion will pass through an altitude of about 100,000 feet. One minute later, the spacecraft will drop below the speed of sound.

At an altitude of about 50,000 feet, at a velocity of some 300 mph, 11 parachutes will begin deploying in sequential fashion to further slow and stabilize the spacecraft. Finally, three pilot chutes will pull out Orion's three 116-foot-wide main chutes, which will begin inflating at an altitude of about 6,000 feet.

That will slow the craft to a relatively gentle 17 mph splashdown in the Pacific Ocean.