A crew of four astronauts embarked on a historic journey toward the moon Wednesday, marking the first time humans have ventured beyond low Earth orbit since the Apollo 17 mission in December 1972. The Artemis II mission, a 10-day test flight, aims to slingshot around the moon without landing, with the crew setting a new record for human deep-space travel.

Commander Reid Wiseman, Victor Glover, Christina Koch, all Americans, and Jeremy Hansen, a Canadian, fired the Orion capsule's engines on Thursday for a "translunar injection," propelling them towards the moon. Nasa described the engine firing, which lasted just under six minutes, as "flawless." By Thursday, the crew had already passed 100,000 miles from Earth. The capsule is expected to travel approximately 4,000 miles beyond the moon before its return, offering unprecedented views of the lunar far side and potentially surpassing 250,000 miles from Earth.

This mission introduces several notable milestones: it marks the inaugural crewed flight of Nasa's Space Launch System (SLS) rocket, and for the first time, a woman (Koch), a person of color (Glover), and a non-American (Hansen) are participating in a lunar journey. Astronauts spent their initial hours in space conducting spacecraft checks, with Koch later having to troubleshoot a malfunctioning toilet with assistance from mission control.

Speaking from the spacecraft, Wiseman described the experience as an "herculean effort," while Koch recounted the "breathtaking aspect of seeing your home planet." Glover reflected on the view of Earth, stating, "From up here, you also look like one thing. We’re all one people." The crew is also scheduled to perform daily exercises on a flywheel device to counter the effects of microgravity on muscles and bones.

The Artemis II flight is a critical step in Nasa's long-term strategy to establish a permanent lunar base, intended as a platform for future deep-space exploration. The program has faced challenges, including years of delays and significant cost overruns, with its launch pushed back from an initial February target. Nasa Administrator Jared Isaacman highlighted the competitive landscape, noting that competition, particularly from countries like China, can be a "great way to mobilize the resources of a nation."

While the mission is not intended to land on the moon, the broader Artemis program aims for a human lunar landing by 2028. This ambitious timeline has drawn scrutiny from some experts, partly due to the program's reliance on the private sector. The crew is on a "free return" trajectory, utilizing the moon's gravity, and is equipped with "survival systems" in their suits, designed to provide up to six days of support in case of a cabin depressurization. A unique passenger on board is a smiley-faced plush toy, designed by an eight-year-old child, serving as a zero-gravity indicator.