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After a record-breaking trip around the moon and back, the Artemis II mission is on its way home to Earth, and preparations are in full swing for its final descent. NASA is targeting splashdown—the moment that the capsule holding the crew will hit the Pacific Ocean—for Friday at 8:07 P.M. EDT. But the hours and minutes leading up to that moment are all critical.
The four Artemis II astronauts—Reid Wiseman, Victor Glover, Christina Koch and Jeremy Hansen—will begin their day at 11:35 A.M. Shortly after that, at approximately 1:50 P.M., they will be working to configure the capsule’s cramped cabin for reentry, stowing away baggage and making sure that everything they need for their journey through the Earth’s atmosphere is ready to go.
Next, NASA has scheduled a final trajectory-course-correction burn for 2:53 P.M. if needed to keep the mission’s Orion capsule, named Integrity by the crew, on track for its final target—Earth.
The astronauts will also review their reentry checklist to make sure that they are each properly in their space suit, which will help protect them on the potentially bumpy ride down, and clear on their responsibilities during the fall.
NASA will livestream the entire process, with the space agency’s own broadcast coverage beginning at around 6:30 P.M.—a little more than an hour before the capsule is due to reenter Earth’s atmosphere.
Moments before it does, the capsule will ditch its bulky service module at about 42 minutes before splashdown. Then, at approximately 7:37 P.M., the Orion capsule will perform a quick burn to maneuver into the right position and attitude for reentry and splashdown. Subsequently, at around 7:53 P.M., Orion will reenter Earth’s upper atmosphere some 400,000 feet above the surface, kicking off a 13-minute descent. At this time, the capsule will be traveling at about 24,000 miles an hour.
Amanda Montañez; Source: NASA (reference)
In the first two minutes of that descent, the spacecraft will plunge 200,000 feet, at which point it will experience temperatures reaching 5,000 degrees Fahrenheit (2,760 degrees Celsius) because air molecules ahead of it will compress so violently, according to NASA. As the capsule falls, it will experience extreme pressure and heat stress. NASA has engineered the Orion capsule with a protective layer, a heat shield, that is designed to char, melt, and disintegrate in such a way that heat won’t penetrate the inside of the spacecraft. It will also go through a six-minute communications blackout, when the heat will effectively cut the crew’s ability to talk to mission control.
At this point, the spacecraft’s thrusters will help to slow the descent. Along the way, the craft will also roll from one side to another to burn off some excess energy.
At about nine minutes into the descent, the spacecraft will be traveling just under the speed of sound at around 35,000 feet above Earth’s surface. At that time, the capsule will begin deploying its parachutes. It has four sets: the forward bay cover parachutes, the drogues, the pilots, and the mains.
The drogue deployment will occur at around 10 minutes in, bringing Orion from 24,000 feet to 6,800 feet. The pilots will then deploy, followed by the mains, which will guide the spacecraft gently down to the water through its final 5,000 feet at around 17 mph.
Splashdown is targeted for 8:07 P.M. in the Pacific Ocean just off the coast of San Diego, Calif. During this 13-minute period, the crew will have effectively traversed 1,701 nautical miles.
There, the USS John P. Murtha will be waiting for them. Within two hours of the astronauts’ splashdown, divers will help extract them from the capsule and get them into helicopters that will carry them to the ship. They will then undergo preliminary medical exams onboard before they return to terra firma.
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