After a brief flyby of the moon, NASA’s Orion spacecraft will touch down in the Pacific Ocean on Sunday, the final leg of the Artemis 1 mission, with huge stakes for the US space agency. The capsule will arrive on Earth at 19:39 (Romanian time). The most intense minutes are when entering the atmosphere, when the heat shield will be exposed to a temperature of 2800 degrees Celsius.

“The most difficult test, other than launch, is re-entry because we need to know if the heat shield is working,” Bill Nelson, NASA’s chief administrator, said recently.

Re-entry into the atmosphere is carried out at a speed of almost 40,000 km/h, and the heat shield must withstand a temperature of 2800 C.

11 high-performance parachutes must deploy to slow the capsule’s descent into the ocean as much as possible.

A speed of 40,000 km/h will be reached at an altitude of 130 km above Terry, and the capsule will have to slow down to 30 km/h before falling into the ocean.

Practically, the capsule will reach a speed that is 30 times faster than the speed of sound, and the temperature at which the heat shield will have to withstand will be half the temperature of the surface of the Sun.

The Orion capsule is not new and flew in 2014, but the 5 meter diameter heat shield was only recently installed and will have to cope with these very high temperatures.

The estimated collision point is 480 km south of the originally calculated location at the start of the mission. A last minute change was needed as the weather forecast indicated bad weather in the north.

A US Navy ship, the USS Portland, was pre-prepared for the capsule recovery operation. Helicopters and inflatable boats will also be involved.

Divers will then attach cables to the capsule to tow it inside the ship, the rear of which will be partially submerged. The water will then be pumped out, allowing the capsule to slowly sink onto a stand specially designed for this purpose.

Operations are expected to last between four and six hours from the time of landing. The ship will then head to San Diego, on the west coast of the United States, where the capsule will land in a few days.

As a reminder, there are NO people on board Orion. A manned mission should be launched in 2024.

The success of the mission, which will last a little more than 25 days in total, is crucial for NASA, which has invested tens of billions of dollars in the American lunar return program Artemis, which aims to prepare for a future trip to Mars, respectively, to test the safety of the capsule and its ability to carry a human crew in the future.

Artemis 1 mission highlights

• November 16: The SLS rocket was successfully launched after previous attempts were marred by problems.
• November 21: After traveling approximately 400,000 km, Orion reached the Moon, touching down 130 km from the Moon’s surface.
• November 25: Orion entered DRO, an elongated orbit around the Moon
• November 26: Orion reaches more than 400,000 km from Earth, surpassing the record set by the space shuttle Apollo 13 in 1970, the furthest point ever reached by a spacecraft capable of carrying humans.
• November 28: Maximum distance from Earth reached as part of the Artemis 1 mission: 430,000 km.
• December 3: Orion re-entered the Moon’s sphere of influence, which meant that the Moon, not the Earth, exerted the dominant gravitational force on the capsule.
• December 5: The capsule came within 128 km of the lunar surface, the shortest distance of the Artemis 1 mission. Immediately afterwards, the engines fired for 3 minutes and 27 seconds to put Orion on a precise trajectory towards Earth.
• December 11: scheduled return to Earth.