NASA’s First Crewed Mission to the Moon in 50 Years Has Never Looked Closer

Today is a proud day for NASA. The agency’s second attempt at a wet dress rehearsal for Artemis 2 went off without a hitch, putting the mission on track to launch as soon as March 6.

In an update posted at 10:18 p.m. on Thursday, NASA said the fueling test had concluded as planned at T-29 seconds. Over the course of this two-day rehearsal, engineers loaded the Space Launch System (SLS) rocket’s core and upper stages with more than 700,000 gallons of liquid hydrogen and liquid oxygen propellants, then ran through the launch countdown, stopping short of firing the rocket’s boosters. Last time, a persistent hydrogen leak forced NASA to end the test prematurely, but the agency’s efforts to fix the issue were apparently successful.

The agency held a press briefing to discuss the results of the redo wet dress rehearsal at 11 a.m. ET on Friday. During the briefing, Artemis launch director Charlie Blackwell-Thompson said the leak repairs proved to be “rock solid†and that there was “really no leakage to speak of.â€

“Very successful day, I’m very proud of this team and all that they accomplished to get us to yesterday and then to go execute with such precision,†Blackwell-Thompson said.

Second time’s the charm

When it finally launches, Artemis 2 will send four astronauts on a trip around the Moon, serving as the first crewed test flight of SLS and the Orion spacecraft. The mission will be the first to send humans back to the vicinity of the Moon since the Apollo era, and this time, they’re venturing deeper into space than any have gone before. Artemis 2 will also pave the way for humanity’s epic return to the lunar surface, currently slated for 2028.

Needless to say, there’s a lot riding on this one. It was disheartening to see the same hydrogen leak that derailed Artemis 1 pop up during the first Artemis 2 wet dress rehearsal. Engineers detected a leak in one of the tail service mast umbilicals on the mobile launcher, prompting them to terminate at the T-5:15 minute mark. These 35-foot-tall (11-meter-tall) structures provide cryogenic fuel lines and electrical cable connections to the SLS core stage.

To fix it, engineers replaced two seals inside the tail service masts and ran a confidence test of the repairs on February 12 but then encountered an issue that reduced the flow of liquid hydrogen into the rocket. Despite this, NASA moved forward with this week’s wet dress rehearsal, and that turned out to be the right move.

The agency reported no propellant leaks or flow anomalies during the test. Aside from a brief lapse in ground communications and a “voltage anomaly†in the booster avionics system, the process went smoothly.

Countdown to launch

With this critical milestone achieved, Artemis 2 is on track to launch during the March window, with opportunities on March 6, 7, 8, 9, and 11.

“While engineers review data from the test, the Artemis II crew is preparing to enter quarantine late Friday, Feb. 20, in Houston,†NASA said in a statement following completion of the WDR. “Although NASA has not set a formal launch date, beginning the roughly 14-day quarantine to limit the crew’s exposure to illness before launch preserves flexibility in the March launch window.â€

The SLS has been subject to heightened scrutiny in the weeks since the first wet dress rehearsal attempt for Artemis 2. During a post-rehearsal press briefing, NASA officials fielded questions about why the rocket was still experiencing hydrogen leaks when engineers had three years to investigate and address the ones that plagued Artemis 1. This recurring issue, which SLS inherited from the Space Shuttle era, has shaken public confidence in its ability to safely and expediently carry crews to space.

Today marks a major win for the beleaguered program. Its true test, however, will arrive with the opening of the March launch window. If NASA can repeat the success of this wet dress rehearsal, we could be going back to the Moon very soon.