Artemis 2 astronauts head for the moon after make-or-break engine burn (video)

Artemis 2 is on its way to the moon.

The mission's Orion capsule aced a crucial translunar injection (TLI) burn this evening (April 2), firing its main engine to leave Earth orbit and head toward our planet's natural satellite.

It was a huge milestone for the Artemis 2 mission, and one of its crewmembers marked it with some poignant words.

"With that successful TLI, the crew is feeling pretty good up here on our way to the moon, and 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," Artemis 2 astronaut Jeremy Hansen, of the Canadian Space Agency, said just after the maneuver.

"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," he added.

Artemis 2 launched Wednesday evening (April 1) from NASA's Kennedy Space Center in Florida, sending four astronauts aloft on the first-ever crewed flight of Orion and its Space Launch System (SLS) rocket. The duo had flown together just once before, on the uncrewed Artemis 1 mission to lunar orbit in 2022.

Orion and its occupants — Hansen and NASA's Reid Wiseman, Victor Glover and Christina Koch — stayed in Earth orbit for more than 24 hours, checking out the capsule's various systems ahead of its planned plunge into deep space.

This afternoon, Artemis 2's mission management team declared the spacecraft fit for this giant leap, greenlighting the TLI burn. So, starting at 7:49 p.m. EDT (2349 GMT), Orion fired its main engine for five minutes and 50 seconds, putting it on a trajectory to loop around the moon and then head back to Earth — without the need for any other major maneuvers.

"Our TLI burn, the burn that gets us going to the moon, is also our deorbit burn," Koch said in a NASA interview before launch. "As soon as we take that burn, we have bought off on basically the rest of the mission."

The TLI burn used Orion's main orbital maneuvering engine, which was salvaged from NASA's space shuttle program and upgraded for an Artemis trip to the moon. The engine has flown in space 19 times before on three different space shuttles. If you strapped it to a car, it would accelerate you from zero to 60 mph (97 kph) in 2.7 seconds.

(Orion has three primary methods of propulsion: its main engine and a set of eight smaller auxiliary engines, which are on its European Service Module, and a set of reaction control thrusters on the capsule itself.)

Artemis 2 is now on track to become the first crewed mission to visit the moon since Apollo 17, which landed on the lunar surface in December 1972. Koch is the first woman ever to leave low Earth orbit, and Glover and Hansen are the first person of color and the first non-American, respectively, to do so. (The Apollo astronauts were all white men.)

Orion will loop around the moon on Day 6 of the mission — about five days, one hour and 30 minutes after liftoff. The Artemis 2 quartet will set another record in the process, getting farther away from Earth than any humans ever have before. They'll beat the mark set by the Apollo 13 astronauts, who traveled a maximum of 248,655 miles (400,171 kilometers) from our planet after suffering an in-flight anomaly that derailed their moon-landing plans.

Artemis 2 will come home on Day 10 of the mission, splashing down in the Pacific Ocean off the coast of San Diego. Full success on this test mission will help pave the way toward the Artemis program's first crewed moon landing, on Artemis 4 in 2028, and the construction of a lunar base a few years after that, if all goes according to plan.