'On our way': Artemis II completes milestone moon burn. What to know.

The Artemis II astronauts have completed a pivotal engine burn and are now on a lunar path to the history books.

The burn, which took the Orion spacecraft out of Earth's orbit, began just before 8 p.m. ET on Thursday, April 2, and lasted just under six minutes, NASA says. It also put the astronauts more than 7,000 miles away from home and counting.

"Houston is a go for the burn," mission control told the astronauts just before they ignited the Orion spacecraft's main engine on the European Service Module − the area below the spacecraft that provides thrust, power, and life support.

Canadian Space Agency astronaut Jeremy Hansen reported back from Orion that the "crew's feeling pretty good up here on our way to the moon."

"We just wanted to communicate to everyone around the planet who’s worked to make Artemis possible that we firmly felt the power of your perseverance during every second of that burn," he said. "Humanity has once again shown what we are capable of, and it’s your hopes for the future that carry us now on this journey around the moon.”

The burn is another major milestone reached during the first crewed moon mission in 50 years and came one day after the Orion spacecraft launched in front of awed spectators from Florida's Kennedy Space Center on April 1.

The 10-day mission is set to bring the astronauts − NASA's Reid Wiseman, Victor Glover and Christina Hammock Koch, and Canadian Space Agency's Jeremy Hansen − farther into space than anyone has ever gone.

Artemis II is testing life-support systems, navigation and communications to prepare for future lunar landings. The expedition will take the astronauts around the moon and back to Earth, but they won't make be landing on the moon this time. (That'll happen with Artemis IV in 2028.)

"This mission is a critical step toward returning humans to the lunar surface and preparing for long‑duration exploration to Mars and beyond," NASA said.

On Day 1, the astronauts made it safely into Earth's orbit and the mission reached the end of its first major propulsion phase, NASA said. Signal was established between the Orion spacecraft and the Deep Space Network. The crew completed a proximity operations demonstration to practice piloting the way they would in future operations when docking with another spacecraft. And they discovered, and fixed, a glitch with the spacecraft's toilet.

Here's what we know about Artemis II:

What are the astronauts doing on April 2 in space?

After a roughly four-hour nap, the crew woke up to “Sleepyhead” by Young and Sick at 7:06 a.m. ET on April 2.

They completed a perigee raise burn, igniting the main engine for 43 seconds to raise the lowest point of Orion's orbit to refine its trajectory around Earth.

The astronauts got to go back to sleep for another four and a half hours, and woke again around 2:35 p.m. ET to some more music, this time “Green Light” by John Legend and Andre 3000.

The crew members then began preparing for the burn that will send them around the moon. They also did some exercise on the spacecraft’s flywheel exercise device, a "key tool" that helps astronauts maintain their fitness during missions.

The pivotal moon burn, which began at about 7:49 p.m. ET., was “flawless,” Lori Glaze, NASA Exploration Systems acting associate administrator, said during a news conference on April 2.

“The burn was the last major firing of this mission,” Glaze said. “From this point forward the laws of orbital mechanics are going to carry our crew to the moon and around the far side and back to the Earth.

She said that the crew was “healthy” and the Orion was “performing really well.”

“We've got eight days of work ahead and we intend to learn as much as we can, everything that we can, that this vehicle that can teach us," she said.

Faulty toilet in space has been fixed, NASA says

While the crew was checking systems on April 1, the astronauts noticed a blinking fault light telling them there was an issue with their toilet.

"The Artemis II crew, working closely with mission control in Houston, were able to restore the Orion spacecraft’s toilet to normal operations following the proximity operations demonstration," NASA said in an update around midnight.

Orion's space toilet is a new system, called the Universal Waste Management System. Astronaut crews on Apollo, Mercury and Gemini missions didn't have toilets: "They urinated into diapers and bags and brought their solid waste mixed with bactericide in bags back home," NASA said.

Orion's toilet uses air flow to pull solid and fluid waste away from the body and into containers. Solids are stored and brought back to Earth with the crew, and liquids are vented into space daily.

This is the Artemis II timeline

The Artemis II mission is expected to take 10 days. Here's what is planned for each phase:

Launch day: Four astronauts launched the evening of April 1 from NASA's Kennedy Space Center in Florida. The Orion capsule separated from the rocket's upper stage to enter a highly elliptical orbit around Earth.

Earth orbit: The first day or so of the mission will see the astronauts in high Earth orbit, conducting various tests and checks on systems.

Translunar injection: On April 2, provided all systems remain functional, a translunar injection burn will take place. This roughly six-minute firing will send the spacecraft on its trajectory to carry the crew around the moon, and also harness lunar gravity to "slingshot" them back to Earth, NASA said.

Moon flyby: On Day 5, Orion will enter the lunar sphere of influence, "marking the point at which the pull of the Moon’s gravity will become stronger than the pull of the Earth’s gravity," according to NASA. A multi-hour moon flyby is planned for April 6, when the astronauts will take photos and document their observations of being some of the first people to ever see parts of the far side of the moon.

On the sixth day, the crew will reach the point closest to the moon and farthest from Earth.

Return: The crew will then spend the next days returning to Earth while continuing tests and observations. Orion will separate key components before plunging into the atmosphere at speeds of about 25,000 mph, while testing the capsule's heat shield. The astronauts will splash down in the Pacific Ocean at the end of their journey.

Contributing: Brooke Edwards, Eric Lagatta, Thao Nguyen, Doyle Rice, and Dinah Voyles Pulver