The four astronauts who made history this week by reaching lunar orbit in more than half a century face re-entry to Earth this Friday, a maneuver as critical as takeoff, with a fall at a speed 45 times faster than that of an airplane and temperatures that are almost half those of the surface of the Sun.
Ditching is scheduled for 20:07 US Eastern Time (00:07 GMT Saturday) in an estimated area of 2,000 nautical miles (3,704 kilometers) in the Pacific.
Aboard the Orion capsule, Reid Wiseman, Christina Koch, Victor Glover and Jeremy Hansen will not only feel their weight multiply by four during the fall, but they will also face extreme temperatures, placing all their hopes in the heat shield, another of the litmus tests of the Artemis II mission.
After the more than eight risky minutes of takeoff, which Artemis II executed impeccably on April 1 in Florida, NASA today faces a critical 13 minutes of reentry once the capsule enters the Earth’s atmosphere, which will culminate with an Orion dive “a couple of hundred miles” off the coast of San Diego (California).
Spanish engineer Carlos García-Galán, responsible for NASA’s Moon Base program, explained to EFE that launch and takeoff are the highest risk maneuvers.
He stressed that this return will allow reaching the speed necessary to test the heat shield that protects astronauts from “the extremely high temperatures generated by friction with the atmosphere upon entering Earth.”
“We can only achieve that speed if we go towards the Moon,” he added about the final phase of this ten-day mission, which orbited the natural satellite – without landing on the moon – and became the first manned mission to reach lunar orbit since 1972.
NASA Administrator Jared Isaacman has assured that he will not be calm until the four crew members return to their families and stated that he will be “thinking about thermal protection systems.”
“I’ll be honest and say that I’ve actually been thinking about reentry since April 3, 2023, when we were assigned this mission,” Rick Henfling, Artemis Return Flight Director, told the press. “It may sound funny, but it’s also literal: we have to go back.”
The phases before landing
Orion is pulled by Earth’s gravity on a free-return trajectory, ensuring fuel-efficient travel.
Before entering the atmosphere, the capsule will separate from the service module 42 minutes before the dive, and 75 miles (about 120 kilometers) above the Earth’s surface, a dozen thrusters will ensure that it is correctly oriented.
This “fireball,” as Glover called it, will enter Earth’s atmosphere at a speed of about 25,000 miles per hour (more than 40,230 kilometers per hour), decelerating at a rate of up to four times the force of gravity.
Testing Orion’s heat shield will be crucial to protect the capsule and its crew from temperatures of around 5,000 degrees Fahrenheit (2,760 degrees Celsius).
Orion will deploy 11 parachutes in stages. Deployed at about 2,700 meters and traveling at 130 miles per hour (210 kilometers per hour), these will slow to less than 20 miles (32 kilometers per hour).
After traveling some 400,000 nautical miles (more than 740,000 kilometers), Orion will splash down and be recovered by the US military. It will take 30 to 45 minutes to recover the astronauts.
Lili Villarreal, director of Artemis Landing and Recovery, who hopes the pickup will be as “successful” as the unmanned Artemis I in 2022, said divers will be the first to approach Orion to assess the air and water around it, and make sure it is safe for the four astronauts to exit.
They will help them climb onto an inflatable platform, where two helicopters pick them up and transfer them to the infirmary of a ship, to then do other medical check-ups on land and then transfer them to Houston (Texas). Meanwhile, Orion will be towed to the ship for its return to the Kennedy Space Center in Florida.
