Artemis II: Return to the Moon Scheduled for Wednesday

Back in January I wrote a post about the upcoming Artemis II launch which, at the time, was expected to lift off in February. Artemis II is the first time astronauts will return to the moon since the early 1970s. This mission will not land on the moon but it will send the astronauts out to circle the moon one time before coming home. The image above shows the plan for the mission.

In early February, NASA held what's known as a wet dress rehearsal which meant filling up the tanks with cryogenically cooled propellant and doing a simulated countdown to see if all systems are working as intended. Unfortunately, the dress rehearsal found some hydrogen leaks which meant a February launch wasn't possible.

 A dress rehearsal countdown for NASA's Artemis II moon rocket, intended to clear the way for a possible February launch, ran into a variety of problems and ultimately was called off early Tuesday because of an out-of-limits hydrogen leak. Shortly after, NASA announced the long awaited flight to send four astronauts on a trip around the moon, was being delayed to March at the earliest...

The test got underway about 45 minutes later than planned, but it initially appeared to be proceeding smoothly as supercold liquid oxygen and hydrogen fuel were pumped into the Space Launch System rocket's first stage tanks. Shortly after, hydrogen began flowing into the rocket's upper stage as planned.

But after the first stage hydrogen tank was about 55% full, a leak was detected at an umbilical plate where a fuel line from the launch pad is connected to the base of the SLS rocket's first stage. After a brief pause, engineers resumed fuel flow but again cut it off with the tank about 77% full.

Some of the problems discovered were repairable at the launch pad but a problem with pressurized helium used to vacate the tanks was not.

Following a successful fueling test last week, engineers were unable to repressurize the upper stage's helium system.

Pressurized helium is used in push propellants to the ICPS engine, to dry out and drain tanks and propellant lines and to "purge" other cavities with the inert gas to minimize the risk of fire. During two fueling tests of the Artemis II SLS rocket, the system worked normally. The problem was found after the second "wet dress" rehearsal countdown was over.

In order to fix the helium problem, NASA had to roll the rocket back into the bay for repairs.

NASA's Space Launch System has re-entered the building.

Artemis II's SLS rocket was moved back into High Bay 3 in the Vehicle Assembly Building following a 10+ hour rollback from LC-39B.

📸Cameron (@nyoomtm) for @TLPN_Official pic.twitter.com/NGrP4oLgMx

— The Launch Pad (@TLPN_Official) February 26, 2026

The problem was repaired and now the rocket is back out at the launch platform and ready to lift off as soon as Wednesday.

At 6:24 p.m. ET Wednesday, four astronauts are scheduled to lift off from NASA’s Kennedy Space Center in Florida, beginning a 10-day journey that will take them looping around Earth and the moon.

The crew — NASA astronauts Reid Wiseman, Christina Koch and Victor Glover and Canadian astronaut Jeremy Hansen — will be the first people to launch toward the moon since the Apollo 17 mission in 1972, more than 50 years ago...

Mission managers plan to begin launch preparations Monday, powering up parts of the rocket and spacecraft. As the astronauts await launch day, they remain in quarantine to limit their exposure to germs.

So that's the plan. Of course there can always be unforeseen circumstances, i.e. another mechanical problem or something as simple as bad weather. But for now the launch Wednesday evening looks likely. The crew for four astronauts gave their spacecraft a nickname.

Wiseman said the crew nicknamed their spacecraft “Integrity,” as a nod to the principle that guided them and their colleagues throughout their training.

“Integrity just fit everything,” he told NBC News in an interview in September. “You can be in integrity and you can be out of integrity. And so for us, as the first crew of Artemis, we strive every day to be in integrity.”

Here's what the mission patch looks like. They designed it so the A II looks a bit like the word "All."

Patch Reveal! @NASA has unveiled the design of Artemis II's mission patch. What do you think? pic.twitter.com/r7hOQwGPqi

— Ryan Caton (@dpoddolphinpro) April 3, 2025

As I mentioned back in January, I'm excited about this because I remember watching some of those final missions to the moon on TV when I was a little kid. I don't remember all the details but I do remember the excitement about space travel and the sense that America was leading the world as explorers into the unknown. 

If the entire mission goes well then NASA will launch the Artemis III mission as soon as sometime next year. Artemis III will return humans to the surface of the moon, somewhere near the south pole.

So stay tuned for the launch. NASA is going to livestream everything starting around noon ET. We'll probably have a post about it so you can watch parts of it here on the site. Finally, here's a 60 Minutes primer on the mission.