After observing the far side of the Moon on the 6th (U.S. time), the ‘Artemis II’ astronauts, now returning to Earth, tested a new garment to prevent dizziness or fainting upon arrival. They also began securing items inside the spacecraft in preparation for atmospheric reentry, and are scheduled to splash down in the Pacific on the 10th.

On the 8th, the National Aeronautics and Space Administration (NASA) stated that Artemis II is flying smoothly toward Earth and that the astronauts are carrying out their scheduled tasks on board as planned. According to NASA, the astronauts that day tested the performance of a special garment called the ‘orthostatic intolerance countermeasure suit’. Its core function is to compress the lower body, including the legs, of the astronaut. This drives blood more strongly toward the head.

The reason this garment was developed is microgravity. The Artemis II astronauts, who left Earth on the 1st, have adapted to weightlessness as their mission has extended beyond a week. As a result, once they complete the mission and return to the ground, a sudden exposure to Earth gravity can produce physiological problems. Blood can pool excessively in the direction of gravity, namely toward the feet, and may not flow sufficiently to the head.

NASA explained, “(For this reason in the past) some astronauts, (after arriving on Earth,) felt dizziness when standing and even fainted.” If, after returning to Earth, an emergency arises on the spacecraft that requires rapid egress, and the astronauts cannot steady themselves due to dizziness, that could cause a serious problem.

Garments that compress the lower body to push blood toward the head already exist. However, they rely on pneumatic compression and therefore require various machines, which places a burden on a spacecraft where interior space is tight and mass must be minimized. This countermeasure suit instead uses the material’s inherent strong elasticity, such as that of shape-memory alloys. No machinery is required.

However, the suit has not been formally issued to the astronauts. The four astronauts took turns wearing a single suit. If it is judged effective here, it will likely be provided in numbers matching crew size for astronauts who depart Earth in the future.

The Artemis II astronauts also plan to do ‘cabin cleaning’ in preparation for the upcoming reentry into Earth’s atmosphere. NASA explained, “All items will be secured for reentry, such as stowing equipment in its proper place.” In the current microgravity state, everything floats inside the spacecraft, but once reentry begins and Earth gravity comes into play, the situation changes. Unsecured objects could collide with the astronauts or onboard equipment.

Barring additional variables during flight, Artemis II is scheduled to splash down in the Pacific near San Diego, California, at 8:07 p.m. on the 10th (9:07 a.m. on the 11th, Korea time).