NASA's Reid Wiseman, Victor Glover, and Christina Koch, and Jeremy Hansen of the Canadian Space Agency, continue to fall back to Earth on a free return trajectory aboard their Orion spacecraft, Integrity, targeting a splashdown in the Pacific Ocean at about 8:05 p.m. ET on April 10.

Over the past eight days, those astronauts became the first people in more than 50 years to leave Earth's orbit and cross the proverbial channel of deep space to fly around the moon.

They ventured farther from Earth than any other human expedition in history. They saw areas and aspects of the lunar surface that no other humans had ever been able to see with their own eyes, and they became the first humans ever to observe a full solar eclipse from lunar space.

They captured striking images of their home planet, and shared a call with their colleagues onboard the International Space Station, marking the first time in spaceflight history that a crew in deep space communicated directly with a crew in low Earth orbit.

But now, it's almost time to come home.

On April 8, the crew started preparing their capsule for arrival, storing equipment and securing items for the upcoming comet-like ride through the Earth's atmosphere.

They started reinstalling their seats into the configuration for launch and reentry, and they tested their orthostatic intolerance garments.

Those special garments are worn underneath the astronaut's spacesuits to help "maintain blood pressure and circulation during the transition back to Earth's gravity," NASA explained.

"After extended time in microgravity, some astronauts experience orthostatic intolerance, a condition that can make it difficult to stand upright without dizziness or fainting. The garment applies lower?body compression to counteract this effect and support a safe return."

The crew was also supposed to demonstrate deployment of an emergency radiation shield inside the cabin, a procedure developed in case astronauts encounter a high dose of radiation beyond Earth orbit. But mission teams decided to forego the demonstration to prepare Integrity for reentry.

The spacecraft also executed short course correction burns on April 7 and April 8, and a third was scheduled for April 9. Also on April 8, the crew took manual control of their ship one last time, turning it around to point the tail end toward the sun.