The American space agency NASA is ready to take home its Orion capsule.
The spacecraft, which has completed a three-week journey around the moon, is targeting a splashdown in the Pacific Ocean off the coast of California.
Without a crew for this test flight, the capsule is expected to carry astronauts on its next outing, assuming everything works as planned in the next few hours.
The parachute-assisted drop into the sea is expected to take place around 09:40 local time (17:40 GMT).
The exercise is part of NASA’s Artemis program, a quest to return people to the lunar surface by the end of this decade.
Fittingly, Sunday marks exactly 50 years since this feat was last achieved by the Apollo 17 crew.
Orion was deployed for the day’s event from its European propulsion module.
This part of the spacecraft performed a big engine maneuver on Monday that propelled the ship away from the Moon and toward Earth.
The speed on the way will be extremely high. The capsule will be moving at 40,000 km/h (25,000 mph) – or 32 times the speed of sound – when it touches down on our planet’s upper atmosphere.
What happens next is critical to the success of the entire enterprise.
Friction and pressure on Orion’s forward-facing surface will generate temperatures that could reach nearly 3,000°C (5,000°F).
The shielding that covers this part of the spacecraft must handle this challenge if Orion is to be trusted to transport astronauts in the future.
“This is our top priority, for a reason,” said Mike Sarafin, Artemis mission manager.
“The heat shield is safety-critical equipment. It’s designed to protect the spacecraft and its passengers, the astronauts on board. So it has to work.”
NASA already has experience of a return to Orion. It conducted an earlier unmanned demonstration of the capsule in 2014. But speeds — and heating conditions — were much lower during that test.
What that previous flight did, however, was demonstrate the effectiveness of the parachute system. Eleven slides are used in sequence to slow the final part of the descent to the ocean surface.
USS Portland will be waiting to take Orion.
Unlike the helicopters that performed lifted recoveries of the Apollo capsules, Orion will be floated in a flooded shaft on the deck of the navy vessel.
NASA’s Melissa Jones, head of the procedure, said various tests and evaluations would be conducted while Orion was still in the water.
“We’ll be very careful with the capsule; we’ll get about an hour and a half of images of that heat shield before it touches anything in the ship. We want to make sure we document all of this so we have the data Orion needs to understand performance.” of the capsule in the future,” he told reporters.
Orion is descending a little below its originally planned position.
The space agency had targeted a spot closer to San Diego, but a predicted cold front is likely to generate an unwanted surge in the ocean, along with rain.
The decision was therefore made to descend to an altitude of approximately 550 km, off the Mexican peninsula of Baja California.
Watching the reentry will be NASA’s partner in the mission, the European Space Agency.
ESA has provided the service module that has guided Orion on its journey for the past three weeks.
It will not splash with the capsule. Instead, she will be detached about 20 minutes before reentry and destroyed as she falls towards Earth over the South Pacific.
European states are about to consider building their own independent crew transportation system. The performance of their Orion service module will give them food for thought.
‘It’s a great starting point, a great foundation; I’ve never doubted the technical capabilities of European industry,’ noted ESA’s director of human and robotic spaceflight, Dr. David Parker, but also noted that Europe still lacks experience with some key additional technologies, including a rocket certified to launch humans.
For now, Europe will continue to deliver service modules.
The unit for the next Artemis mission has already been delivered to NASA, as well as a third vehicle, the one that will be used in the moon landing mission, currently scheduled for late 2025 or 2026.