This morning, NASA officially announced a no earlier than March 6th target launch date for Artemis II. That date is contingent on completion of some work at the launch pad, and a positive result from the upcoming Launch Readiness Review, which is scheduled for late next week.
NASA is moving ahead with a second wet dress rehearsal, or WDR-2, for the Artemis II mission. Launch controllers will take their positions in the Launch Control Center at 6:40 PM ET tonight (Feb. 17), kicking off a nearly 50-hour countdown sequence. The simulated launch window opens at 8:30 PM on February 19th and extends four hours.
NASA engineers are poring over data from tests conducted on February 12th as part of the Artemis II vehicle’s pre-flight checkouts. During the tests, operators partially filled the Artemis II core stage liquid hydrogen tank to evaluate newly replaced seals in the propellant loading area.
When NASA wrapped up the first Artemis II wet dress rehearsal on February 3 at Kennedy Space Center, they had successfully filled the SLS rocket’s tanks with cryogenic propellant. That was the good news, but the less welcome bad news was that the test revealed higher-than-allowable hydrogen gas leaks at the Tail Service Mast Unit on the launch pad. Obviously, those leaks must be repaired before a launch attempt.
Not long after propellant draining was complete after WDR-1, technicians began working to access the TSMU umbilical. They detached both the rocket-side and ground-side interface plates to inspect the area where elevated hydrogen levels were detected, and replaced seals around two fueling lines.
The two tail service masts — each about three stories tall — provide the cryogenic propellant lines and electrical cable connections to the SLS core stage. They tilt back before launch and include “quick disconnects” — mechanisms that instantaneously detach at liftoff to ensure safe retraction.
Reconnecting the interfaces is expected to be complete by Monday, Feb. 9. Engineers are still evaluating the root cause of the leak, and the removed seals are being analyzed. NASA also plans additional testing at Stennis Space Center in Bay St. Louis, Mississippi, to evaluate the dynamics of the interface plates. Engineers are reviewing options to verify the repair before committing to the next full wet dress rehearsal.
Here’s a breakdown of the repairs underway and the operational changes NASA is making for WDR-2:
| Type | Change | Details |
|---|---|---|
| Hardware Fix | Two seals replaced | Seals replaced around fueling lines at the tail service mast umbilical where hydrogen concentrations exceeded allowable levels. Removed seals are being analyzed and additional plate dynamics testing is planned at Stennis. |
| Operations | Orion hatch closed before test | The crew module hatch will be sealed prior to the rehearsal. The closeout crew — who on launch day help astronauts into their seats and close both Orion hatches — will not be deployed to the pad. |
| Operations | Crew access arm stays extended | The arm will not be retracted during the next rehearsal. Engineers successfully demonstrated during the Feb. 3 test that the ground launch sequencer can retract it during the final countdown phase, so that objective is already complete. |
| Timeline | One extra hour in countdown | NASA has added 30 minutes of extra hold time at each of two planned holds — one before and one after tanking operations — to allow more time for troubleshooting. The total countdown is now one hour longer. This does not affect the crew’s launch-day timeline. |
| Focus Shift | Rehearsal focused on fueling | With the crew access arm retraction and other pad objectives already demonstrated, the next WDR will concentrate on tanking operations and verifying the hydrogen leak repair. |
Source: NASA, “NASA Conducts Repairs, Analysis Ahead of Next Artemis II Fueling Test,” Feb. 8, 2026
NASA continues to eye March as the next potential launch opportunity but will not set a targeted launch date until after completing a successful wet dress rehearsal and reviewing the data. The critical second WDR is set to start as soon as this Friday, February 13th.
Teams at Kennedy Space Center conducted and mostly completed a critical Wet Dress Rehearsal for the launch of the Artemis II rocket and ground support teams yesterday. The test was not without problems: Hydrogen leaks at the tail mast area of the pad and an issue closing Orion’s hatches bedeviled the tests, resulting in NASA announcing that the launch of the Artemis II mission is now no earlier than March 6, 2026.
“The Artemis II wet dress rehearsal countdown was terminated at the T-5:15 minute mark due to a liquid hydrogen leak at the interface of the tail service mast umbilical, which had experienced high concentrations of liquid hydrogen earlier in the countdown, as well,” NASA said.
In a press conference today, Artemis II Launch Director Charlie Blackwell-Thompson said, “When we got into the LH2 fast fill—which was around 12:29—is when we picked up our first leak in the SMU, in the cavity, which is where the flight and the ground plate come together. It’s that cavity in between. It’s in our eight-inch fill and drain line there. We have a QD that connects those two together.”
“It was similar to some of the signatures we saw during Artemis I. Our leak rate was a little bit higher—somewhere around 12 to 14%,” Blackwell-Thompson continued. “We tried a contingency procedure that we used during Artemis I: you let that QD warm up, you let the seal warm up, and you try it again. We did that a couple of times, worked our way through it, and were able to load the core stage all the way to replenish.”
When asked what items were missed in the Wet Dress Rehearsal, Blackwell-Thompson said, “What we didn’t get to do: we wanted to get through terminal count. We wanted to get inside terminal count, hold, and verify our three-minute hold capability—tanks in launch-ready state and you can hold them for up to three minutes.”
“We also wanted to demonstrate a recycle: come down, have a planned cutoff, come back and retarget a new T-0 within the launch window. Didn’t get a chance to do that.”
Before the March window, NASA’s engineers and mission managers will review data, equipment and procedures from the WDR yesterday and they will conduct a second Wet Dress Rehearsal before committing to a launch date. Of key interest are the Tail Mast interfaces that deliver LH2 to the rocket’s propellant tanks.
“With the conclusion of the wet dress rehearsal today, we are moving off the February launch window and targeting March for the earliest possible launch of Artemis II,” NASA Administrator Jared Isaacman said today. “With more than three years between SLS launches, we fully anticipated encountering challenges. That is precisely why we conduct a wet dress rehearsal. These tests are designed to surface issues before flight and set up launch day with the highest probability of success.”
(Subject to Adjustments)
| Launch Window Opening | Window | |||
|---|---|---|---|---|
| Date | Local Time | UTC | Lighting | Mins |
| Mar 6 | 8:29 PM EST | Mar 7, 01:29 | 2.05 hrs after sunset | 120 |
| Mar 7 | 8:57 PM EST | Mar 8, 01:57 | 2.51 hrs after sunset | 120 |
| Mar 8 | 10:56 PM EDT | Mar 9, 02:56 | 3.48 hrs after sunset | 120 |
| Mar 9 | 11:52 PM EDT | Mar 10, 03:52 | 4.40 hrs after sunset | 120 |
| Mar 10 | 12:48 AM EDT | Mar 10, 04:48 | 5.36 hrs after sunset | 115 |
| Apr 1 | 6:24 PM EDT | Apr 1, 22:24 | 1.28 hrs before sunset | 120 |
| Apr 3 | 8:00 PM EDT | Apr 4, 00:00 | 0.30 hrs after sunset | 120 |
| Apr 4 | 8:53 PM EDT | Apr 5, 00:53 | 1.17 hrs after sunset | 120 |
| Apr 5 | 9:40 PM EDT | Apr 6, 01:40 | 1.95 hrs after sunset | 120 |
| Apr 6 | 10:36 PM EDT | Apr 7, 02:36 | 2.87 hrs after sunset | 120 |
| Apr 30 | 6:06 PM EDT | Apr 30, 22:06 | 1.86 hrs before sunset | 120 |
↔ Scroll table on mobile
As of: February 3, 2026 at 8:32 AM EST
A liquid hydrogen leak at the LC-39B’s Tail Mast umbilical connection to SLS’s core stage forced engineers into a troubleshooting effort that pushed the countdown about two hours behind schedule. The team cycled through several repair attempts, first halting LH2 flow, then letting the interface warm so seals could seat themselves properly, and finally by tweaking propellant flow rates before pressing ahead. Ultimately, they were successful in their efforts and got the 322-foot tall rocket fully fueled, but a great deal of time was lost during the effort.
Secondly, a recently replaced valve tied to Orion’s crew hatch pressurization system needed to be retorqued, and closeout work ran longer than expected. NASA stated around 10 PM last night that, “The closeout crew remains in the White Room and has closed the Orion spacecraft’s crew module hatch. While performing seal pressurization checks on the counterbalance assembly, which could be used to help open the hatch, a valve associated with Orion’s hatch pressurization was inadvertently vented. The counterbalance assembly then needed to be repressurized to allow work to continue.”
Finally, communications issues from SLS to ground caused some issues and will need to be remediated prior to the next Wet Dress Rehearsal, much less any launch attempt in March.
Clearly, there’s some work to do before Artemis II will be ready to fly.
The Artemis II crew has been released from quarantine for the time being. Once a new potential launch date becomes clearer, they will return to quarantine and fly to Kennedy Space Center for final preparations prior to launch.
NASA has scheduled a 1 PM ET press conference to offer more details.
The countdown for the Artemis II Wet Dress Rehearsal is underway at Kennedy Space Center. Yesterday at 8:13 PM ET, or L-48:40 hours, the simulated countdown began in preparation for a test launch window opening at 9 PM tomorrow, February 2nd.
Artemis II will not launch during this countdown, of course, as it is just a test countdown. The Artemis II crew will not be aboard during Orion the WDR.
Sometime around 1 AM ET Tuesday, or February 3rd, the WDR will conclude.
After the test cycle concludes, engineers and mission managers will review data gathered during the Wet Dress Rehearsal. This process may take a few days as each major system is reviewed. Since Artemis I, NASA has implemented changes to the liquid Hydrogen systems at LC-39B. That will be a particular area of concern, as H2 leaks bedeviled the Artemis I countdowns both in WDR and later on the night it launched.
After the Data Review, a Flight Readiness Review can be held, during which all aspects of the mission are reviewed: the SLS rocket, the Orion spacecraft, ground systems at the Cape, and the status of the recovery teams that would be first responders to a major anomaly, should one occur, and many others.
The FRR is last major review for the flight, and in it, the Artemis II management team will need to give the mission permission to proceed towards a launch. Only after that milestone is achieved will a launch date and time be announced by NASA.
| L-49 Hours, 15 Minutes and Counting | |
|---|---|
| Time | Activity |
| L-49H 15M | Launch team arrives on stations; countdown begins |
| L-48H 40M | Countdown clock begins |
| L-48H 45M – L-39H 45M | LOX/LH2 system preparations for vehicle loading |
| L-47H 30M – L-38H 30M | Fill water tank for sound suppression system |
| L-40H 30M – L-39H | Interim Cryogenic Propulsion Stage (ICPS) powered up |
| L-39H 30M – L-38H 45M | Core stage powered up |
| L-38H 45M – L-34H 30M | Final preparations of four RS-25 engines |
| L-34 Hours, 30 Minutes and Counting | |
|---|---|
| Time | Activity |
| L-33H 45M – L-33H 10M | ICPS powered down |
| L-32H 30M – L-28H 30M | Charge Orion flight batteries to 100% |
| L-30H 30M – L-23H 30M | Charge core stage flight batteries |
| L-19H 30M – L-16H | Orion crew suit regulator leak checks |
| L-19H 15M – L-17H 45M | ICPS powered up for launch |
| L-15 Hours and Counting | |
|---|---|
| Time | Activity |
| L-14H 30M – L-13H | All non-essential personnel leave Launch Complex 39B |
| L-13H 15M – L-11H 05M | Air-to-GN2 changeover and vehicle cavity inerting |
| L-12H 45M – L-11H 15M | Ground Launch Sequencer (GLS) activation |
| L-11 Hours, 40 Minutes and Counting | |
|---|---|
| Time | Activity |
| L-11H 35M – L-9H 20M | Built-in hold: 2 hours, 15 minutes |
| L-11H 40M – L-10H 30M | Weather and tanking briefing |
| L-10H 20M | Go/No-Go decision to begin tanking |
| L-10H 20M – L-9H | Orion cold soak |
| L-10H 10M – L-9H 50M | Core stage LOX transfer line chilldown |
| L-10H 10M – L-9H 25M | Core stage LH2 chilldown |
| L-10 Hours and Counting | |
|---|---|
| Time | Activity |
| L-9H 50M – L-9H 10M | Core stage LOX main propulsion system chilldown |
| L-9H 25M – L-9H | Core stage LH2 slow fill start |
| L-9H 20M | Resume T-Clock from T-8H 10M |
| L-9H 10M – L-8H 55M | Core stage LOX slow fill |
| L-9H – L-7H 40M | Core stage LH2 fast fill |
| L-8H 55M – L-6H 10M | Core stage LOX fast fill |
| L-8H 45M – L-8H 10M | ICPS LH2 chilldown |
| L-8H 10M – L-7H 25M | ICPS LH2 fast fill start |
| L-7H 45M – L-6H | ICPS LOX main propulsion system chilldown |
| L-7H 40M – L-7H 30M | Core stage LH2 topping |
| L-7H 30M – terminal | Core stage LH2 replenish |
| L-7H 25M – L-7H 05M | ICPS LH2 vent and relief test |
| L-7H 05M – L-6H 55M | ICPS LH2 tank topping start |
| L-6H 50M – terminal | ICPS LH2 replenish |
| L-6H 10M – L-5H 40M | Orion communications system activated (RF to Mission Control) |
| L-6H 10M – L-5H 40M | Core stage LOX topping |
| L-6 Hours and Counting | |
|---|---|
| Time | Activity |
| L-6H – L-5H 15M | ICPS LOX fast fill |
| L-5H 40M – terminal | Core stage LOX replenish |
| L-5H 40M | Stage pad rescue; closeout crew assemble |
| L-5H 15M – L-5H | ICPS LOX vent and relief test |
| L-5H – L-4H 40M | ICPS LOX topping |
| L-4H 40M – terminal | ICPS LOX replenish; all stages replenish |
| L-4H 40M | Built-in hold: 40 minutes |
| L-4H 40M – L-4H 25M | Closeout crew to white room |
| L-4H 30M – L-4H 20M | Crew Module hatch preps and closure |
| L-4H 20M – L-3H 20M | Counterbalance mechanism hatch seal/press decay checks |
| L-3H 20M – L-2H 40M | Crew Module hatch service panel install/closeouts |
| L-2H 40M – L-2H 20M | Launch Abort System (LAS) hatch closure for flight |
| L-1H 45M – L-1H 40M | Closeout crew departs Launch Complex 39B |
| L-1H 10M | Launch Director brief – Flight vehicle/TPS scan results with CICE |
| L-40 Minutes and Holding | |
|---|---|
| Time | Activity |
| L-40M | Built-in hold: 30 minutes |
| L-25 Minutes and Holding | |
|---|---|
| Time | Activity |
| L-25M | Transition team to Orion-to-Earth comm loop following final NTD briefing |
| L-16M | Launch Director polls team for “Go” for launch |
| T-10 Minutes – Terminal Count | |
|---|---|
| Time | Activity |
| T-10M | Ground Launch Sequencer (GLS) initiates terminal count |
| T-8M | Crew Access Arm retract |
| T-6M | GLS go for core stage tank pressurization; Orion set to internal power |
| T-5M 57S | Core stage LH2 terminate replenish |
| T-4M | GLS go for core stage APU start; APU starts; Core stage LOX terminate replenish |
| T-3M 30S | ICPS LOX terminate replenish |
| T-3M 10S | GLS go for purge sequence 4 |
| T-2M 02S | ICPS switches to internal battery power |
| T-2M | Booster switches to internal battery power |
| T-1M 30S | Core stage switches to internal power; hold for 3-minute certification hold time verification |
| T-1M 20S | ICPS enters terminal countdown mode |
| T-50S | ICPS LH2 terminate replenish |
| T-33S | GLS sends “Go for Automated Launch Sequencer” command; GLS Cutoff/Recycle |
Source: Countdown Begins for Artemis II Wet Dress Rehearsal, NASA, January 31, 2026.
SLS began its slow and deliberate journey to Launch Pad 39B from the Vehical Assembly Building (VAB) early Saturday morning at Kennedy Space Center, marking a major milestone in the agency’s quest to return astronauts to the Moon for the first time in more than half a century.
The 322-foot-tall rocket emerged from the cavernous Vehicle Assembly Building at 7:04 a.m. EST, carried atop Crawler-Transporter 2 for the four-mile trek to the historic launch complex. The combined stack — rocket, Orion capsule, and mobile launcher — weighs approximately 11 million pounds and is traveling at a top speed of just under one mile per hour, with the journey expected to take between eight and twelve hours. At the time of this writing, that journey is still underway and should conclude late this afternoon or early this evening.
Hundreds of space center workers, family members, and guests gathered along the crawlerway to witness the spectacle as the towering white rocket inched past against a clear Florida sky. NASA Administrator Jared Isaacman and the four Artemis II astronauts were on hand to mark the occasion.
“Wow. LETS GO!!!” Commander Reid Wiseman posted on X alongside a photo of the rocket moving out of the VAB. In a subsequent post, he called the SLS and Orion “engineering art.”
Once the rocket reaches Launch Pad 39B, teams will immediately begin connecting ground support equipment, including electrical lines, environmental control system ducts, and cryogenic propellant feeds. Engineers will then power up the integrated systems for the first time to verify everything functions properly with the mobile launcher and pad infrastructure.
A wet dress rehearsal is scheduled for late January or early February. During this critical test, ground crews will load more than 700,000 gallons of cryogenic liquid oxygen and liquid hydrogen into the rocket’s tanks and conduct multiple countdown sequences, including several holds and recycles in the final minutes to validate launch procedures.
Artemis Launch Director Charlie Blackwell-Thompson said a February launch remains possible but emphasized that the timeline depends on the outcome of upcoming testing. “We need to get through wet dress,” she said during a pre-rollout briefing yesterday.
NASA’s launch window opens February 6, with additional opportunities on February 7, 8, 10, and 11. Due to the orbital mechanics governing the mission’s trajectory to the Moon, only about one week of launch opportunities exists each month, followed by roughly three weeks without viable windows.
NASA’s moon rocket is finally hitting the road.
The agency announced that the fully stacked Space Launch System rocket and Orion spacecraft will begin their four-mile trek from the Vehicle Assembly Building to Launch Complex 39B no earlier than Saturday, January 17, with first motion expected around 7 a.m. ET. The journey aboard Crawler-Transporter 2 will take up to 12 hours.
| Distance | Approximately 4 miles (6.4 km) |
|---|---|
| Speed | 0.82–1 mph (1.3–1.6 km/h) loaded |
| Total Time | 10–12 hours, depending on conditions and stops |
| Method | Crawler-Transporter 2 (CT-2), a 6.6-million-pound vehicle |
| Purpose | Transport the fully assembled rocket from the VAB to Launch Pad 39B for wet dress rehearsal and final launch preparations |
Teams have been working around the clock to close out remaining tasks ahead of rollout, though the date could shift if additional time is needed for technical preparations or weather.
The rollout marks the beginning of final integration and testing for what will be the first crewed mission beyond Earth orbit in more than 50 years. Once at the pad, NASA astronauts Reid Wiseman, Victor Glover, and Christina Koch, along with Canadian Space Agency astronaut Jeremy Hansen, will conduct a final walkdown before launch preparations continue.
A wet dress rehearsal is planned for late January, during which teams will load more than 700,000 gallons of cryogenic propellants and run through countdown procedures. The earliest launch window opens February 6, with additional opportunities on February 7, 8, 10, and 11.
NASA has published its launch window availability for Artemis II, the agency’s first crewed lunar mission in over 50 years, with opportunities spanning February through April 2026. The Space Launch System rocket and Orion spacecraft are scheduled to roll out from the Vehicle Assembly Building to Launch Complex 39B NET January 17th.
The four-mile journey aboard Crawler-Transporter 2 will take up to 12 hours before the integrated launch structure and rocket arrive at their final destination.
After Artemis II is rolled out to LC39B, engineers and technicians will start pad integration tasks, including connecting essential ground support equipment such as electrical lines, environmental control system ducts, and cryogenic propellant feeds. After those tasks are successfully completed, teams will then power up all integrated systems for the first time at the pad.
All windows are 120 minutes, except for March 11th, which offers a slightly shorter 115-minute window.
The published windows reflect careful consideration of lighting conditions, so that Orion is not in darkness for more than 90 minutes at a time post-launch, therefore allowing its solar arrays to keep generating power and the spacecraft to stay within its thermal limits. Dates that would put Orion into extended eclipses are removed from consideration.
Another consideration is that the launch window constraints ensure optimal conditions for tracking cameras and abort scenarios during the critical ascent phase.
NASA notes all dates remain subject to adjustments as the mission progresses through final preparations.
The earliest available launch window opens on February 6, 2026, at 9:41 pm ET, with a 2-hour window. Launch opportunities continue through February 11th, followed by a brief gap, then resume mid-month. Each window in the February series shifts progressively later into the night, with the final February opportunity on the 11th occurring at 1:05 AM EST.
Should weather or technical issues prevent a February launch, NASA has identified windows throughout March and April. The March series begins on the 6th at 8:29 PM ET, while April windows open as early as 6:24 PM ET on April 1st—notably the only daytime launch opportunity in the released schedule, occurring approximately 1.3 hours before sunset.
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