NASA's Artemis II Keeps Leaking Liquid Hydrogen, And It's Starting To Cause Problems

NASA plans to return people to the moon with its Artemis II mission, which would be the first crewed mission to the moon in 50 years. This historic launch, however, has hit a snag. During a rehearsal for the launch, there was a liquid hydrogen leak where propellant is loaded into the rocket itself. Despite troubleshooting issues, this leak plagued the entire rehearsal and ultimately resulted in the launch of Artemis II being pushed back. It was supposed to launch on February 8, 2026. Now, it has been delayed until March.

Artemis II is the next progressive mission from Artemis I. Artemis I sent an uncrewed spacecraft to the moon and back across three weeks in late 2022. Artemis II will be sending a crew of four astronauts — Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen — in a 10-day trip around the moon. Not only does NASA see this launch as instrumental in sending people back to the moon, but it also is a key part of its overall Artemis mission series. Artemis III is expected to send people onto the moon's surface in 2028, and Artemis IV has the ambitious plan of building the beginnings of a space station on the moon.

Now, eyes are on NASA as this launch is pushed back just days before it was supposed to happen. Though these things can be quite common in space flight, this leaking problem was already seen before with Artemis I.

Artemis I also had liquid hydrogen leaking problem. The issue caused so much of a challenge that the original spring 2022 launch date got pushed all the way back to fall 2022. Now, a similar situation rears its head again with Artemis II. This isn't the only potentially dangerous problem the spacecraft has, with concerns about the heat shield, as well.

NASA began what is known as a wet dress rehearsal on January 31, 2026. An event supposed to span across about two days. During this rehearsal, the liquid hydrogen began to leak. Engineers had to stop the propellant flow completely and then readjust it again, a process that took several hours. Despite that success, the leak started up again later during the rehearsal during the countdown practice. The problem was so bad that the rehearsal had to end early.

There were a few other issues that plagued the rehearsal, including losing audio communication and having pressurization issues with a crew module hatch. Since the initial launch date is now abandoned, the four astronauts themselves have been able to come out of their two-week quarantine. They won't have to go back until a new launch date is set.

NASA Administrator Jared Isaacman took to X to release a statement about the incident on February 3, 2026. In his post, he stated that NASA is "moving off the February launch window and targeting March for the earliest possible launch of Artemis II." He also said, "With more than three years between SLS launches, we fully anticipated encountering challenges," and that "safety remains our top priority, for our astronauts, our workforce, our systems, and the public ... we will only launch when we believe we are as ready to undertake this historic mission."

With March as the new launch date, it's hard to not make comparisons to Artemis I. It also had a spring launch date, but it didn't actually leave Earth until November. With a leak plaguing both missions, it's easy to wonder if Artemis II also won't actually achieve launch until much later in 2026, as well. Given that this mission will be history-making and that NASA has big plans for Artemis and the moon, it's critical for everything to go right.

As we wait for Artemis II to head to the moon, there are a handful of ways you can watch NASA's launch, including seeing it in-person from the Kennedy Space Center. Eyes will be on the next launch to be hopefully in March, and on any more liquid hydrogen leaking in particular.