Artemis I Update: Countdown is Underway for Wet Dress Rehearsal

At approximately 5 p.m. EDT, or L-45 hours, 40 minutes before the initial targeted test T-0, the launch team arrived at their stations inside the Launch Control Center at NASA’s Kennedy Space Center in Florida. The countdown is now underway for the wet dress rehearsal test for NASA’s Artemis I mission.

Prior to “call to stations” the team completed several activities including closing the Orion crew module hatch and conducting leak checks. Technicians then closed the hatch on the launch abort system and conducted final activities in the White Room, the access point between Orion and the Mobile Launcher. The crew access arm, where the White Room is located, was retracted away from the spacecraft and rocket. On March 31, Orion was powered-up and will remain on throughout the duration of the test.

Teams are now filling the sound suppression system with water at the launch pad, which is used to dampen and absorb acoustic energy during liftoff. Even though the Space Launch System engines will not fire during this test, teams are practicing carrying out operations as they would on launch day.

Overnight, teams will charge the SLS core stage batteries and configure ground systems to power up the stage, and purge and remove ducts for the RS-25 engines. The next operational update will be posted the morning of April 2.

Watch a live video stream of the rocket and spacecraft at the launch pad now on the Kennedy Newsroom YouTube channel. In addition to updates on this blog, NASA also will provide operational updates on the Exploration Ground Systems Twitter account from Jeremy Parsons, deputy manager for Exploration Ground Systems.

Artemis I Wet Dress Rehearsal Test on Track

The launch team is on track to begin the countdown for the Artemis I wet dress rehearsal test. Meteorologists with the U.S. Space Force Space Launch Delta 45 currently predict favorable weather conditions for tanking on April 3. The primary weather concern is lightning. There is currently less than a 10% chance of lightning within five nautical miles of the launch pad. Weather constraints stipulate there must be less than a 20% chance lightning within 5 nautical miles of pad during the first hour of tanking. Meteorologists are also predicting a 10% chance of winds greater than 23 knots on April 3, when tanking begins. Winds must not be above 37.5 knots and the temperature cannot be below 41 degrees Fahrenheit.

The countdown is set to begin at 5 p.m. EDT April 1 with “call to stations” at L-45 hours, 40 minutes, when teams begin arriving to Kennedy Space Center’s Launch Control Center. The approximately two-day wet dress rehearsal test for the Space Launch System rocket and Orion spacecraft will run the Artemis I launch team through operations to load propellant into the rocket’s tanks, conduct a full launch countdown, demonstrate the ability to recycle the countdown clock, and also drain propellants to give them an opportunity to practice the timelines and procedures they will use for launch.

In addition to updates on this blog, NASA will provide live updates on the Exploration Ground Systems Twitter account. NASA is streaming live video of the rocket and spacecraft at the launch pad on the Kennedy Newsroom YouTube channel. Activity at the launch pad likely will not be visible during the majority of the countdown, but some venting may be seen during tanking on April 3.

Artemis I Wet Dress Rehearsal Preparations Underway   

Engineers and technicians are continuing to prepare for the Artemis I wet dress rehearsal test which is slated to begin on April 1 and conclude on April 3.    

 The wet dress rehearsal will begin at 5 p.m. EDT on April 1 with “call to stations,” when members of the launch control team at Kennedy Space Center in Florida will arrive to the firing rooms in the Launch Control Center and start the approximately two-day test launch countdown.  The team will target a two-hour test window that opens at 2:40 p.m. April 3. 

 The countdown for the wet dress rehearsal will follow a similar timeline as the team will use on the day of launch. Below are the approximate times for countdown milestones during the wet dress rehearsal test. All times below are Eastern. 

During the test, the timing for some events on account of several planned operational demonstrations tied to specific capabilities and test objectives may differ from the day of launch countdown. These demonstrations include tests on the cryogenic systems and an approximately three-minute hold inside the terminal count, which would not normally occur on launch day. If needed, the test team also may hold as necessary to verify conditions before resuming the countdown, or use the test window or extend beyond it, if consumables and resources allow them to complete test objectives. 

The following activities will occur for the Space Launch System (SLS) rocket, the Orion spacecraft, and supporting ground systems: 

Prior to Call to Stations 

  • The Orion crew module hatch is closed (will occur at ~L-37.5 hours for launch) 
  • The crew access arm is retracted (will occur at ~L-30 hours for launch) 
  • Leak checks are completed on the Orion spacecraft and the launch abort system is closed (will occur at ~L-29 hours, 30 minutes for launch) 

5 p.m., April 1 – L-45 hours and counting   

  • The launch team arrives on their stations and the countdown begins (L-45, 40 minutes hours)  
  • Fill the water tank for the sound suppression system (L-45 hours)  
  • The Orion spacecraft powered up start (L-41 hours)  
    • May be powered earlier during the test 
  • The SLS core stage is powered up (L-35 hours, 20 minutes)  
  • Final preparations of the four RS-25 engines complete (L-30 hours, 30 minutes)  
    • Engines will not fire during this test 
  • Side flame deflectors are moved into place (L-21 hours)   

1:40 a.m., April 3 – L-13 hours and counting   

  • The SLS interim cryogenic propulsion stage (ICPS) is powered up (L-12 hours, 50 minutes)  
  • All non-essential personnel leave Launch Complex 39B (L-12 hours)    

6 a.m. – L-8 hours, 40 minutes and counting  

  • Built in countdown hold begins and lasts approximately 1.5 hours (L-8 hours, 40 minutes)  
  • The launch director and mission management team chair conduct a weather and tanking briefing (L-8 hours, 20 minutes)   
  • The launch director and mission management team chair decide if they are “go” or “no-go” to begin tanking the rocket (L-7 hours, 50 minutes)   

6:40 a.m. – L-8 hours and counting  

  • 7:20 a.m.: Core stage LOX chilldown start (L-7 hours, 20 minutes)  
  • 8:15 a.m.: Core stage LOX slow fill start (L-6 hours, 25 minutes)  
  • 8:30 a.m.: Core stage LOX fast fill start (L-6 hours, 10 minutes) 
  • 8:35 a.m.: Core stage LH2 chilldown start (L-6 hours, 5 minutes)  
  • 8:40 a.m.: Core stage LH2 slow fill start (L-6 hours)  
  • 9:00 a.m.: Core stage LH2 fast fill start (L-5 hours, 40 minutes)  

  10:10 a.m. – L-4 hours, 30 minutes and counting   

  • 10:10 a.m.: Core stage LH2 topping start (L-4 hours, 30 minutes)  
  • 10:15 a.m.: ICPS LH2 chilldown (L-4 hours, 25 minutes)  
  • 10:15 a.m.: Core stage LH2 replenish start (L-4 hours 25 minutes)  
  • 10:20 a.m.: Orion communications system activation start (RF to Mission control) (L-4 hours, 20 minutes)  
  • 10:40 a.m.: ICPS LH2 fast fill (L-4 hours) 

11:10 a.m. – L-3 hours, 30 minutes and counting   

  • 11:15 a.m.: Core stage LOX topping start (L-3 hours, 25 minutes)  
  • 11:20 a.m.: Core stage LOX replenish start (L-3 hours, 20 minutes)  
  • 11:20 a.m.: ICPS LOX chilldown start (L-3 hours, 20 minutes)  
  • 11:25 a.m.: ICPS LH2 validation and leak test start (L-3 hours, 15 minutes)  
  • 11:40 a.m.: ICPS LH2 tanks load topping start (L-3 hours)  
  • 11:40 a.m.: ICPS/SLS telemetry data verified with mission control and SLS Engineering Support Center (L-3 hours)  
  • 12 p.m.: ICPS LH2 replenish start (L-2 hours, 40 minutes)  
  • 12 p.m.: ICPS LOX validation and leak test (L-2 hours, 40 minutes)  
  • 12:20 p.m.: ICPS LOX topping start (L-2 hours, 20 minutes)  
  • 12:30 p.m.: ICPS LOX replenish start (L-2 hours, 10 minutes)  
  • 12:40 p.m.: WDR-specific core stage LOX/LH2 stop flow and recover test (L-2 hours through L-55 minutes) 

  2 p.m. – L-40 minutes and holding   

  • 2 p.m.: Final NASA Test Director briefing is held  
  • 2 p.m.: Built in 30-minute countdown hold begins  
  • 2:25 p.m.: The launch director polls the team to ensure they are “go” for terminal count for test purposes

  2:30 p.m. – T-10 minutes and counting (WDR Run 1) 

  • 2:34 p.m.  
    • Orion ascent pyros are armed (T-6 minutes)  
    • Orion set to internal power (T-6 minutes)  
    • Core Stage LH2 terminate replenish (T-5 minutes, 57 seconds)  
  • 2:36 p.m.  
    • Core Stage auxiliary power unit starts (T-4 minutes) 
    • Core stage LOX terminate replenish (T-4 minutes)   
    • ICPS LOX terminate replenish (T-3 minutes, 30 seconds)  
  • 2:38 p.m. 
    • ICPS switches to internal battery power (T-1 minute, 56 seconds)  
    • Core stage switches to internal power (T-1 minute, 30 seconds)  
    • ICPS enters terminal countdown mode (T-1 minute, 20 seconds)  
  • 2:39 p.m. 
    • ICPS LH2 terminate replenish (T-50 seconds)  
    • Ground launch sequencer sends “cut-off” command (T-33 seconds)  

Perform Critical Safing and Planned Recycle back to T-10 minutes and holding (takes approximately one hour) 

 T-10 minutes and counting  (WDR Run 2) 

  • Orion ascent pyrotechnics are armed (T-6 minutes)  
  • Orion set to internal power (T-6 minutes)  
  • Core Stage LH2 terminate replenish (T-5 minutes, 57 seconds)  
  • Core Stage auxiliary power unit starts (T-4 minutes) 
  • Core stage LOX terminate replenish (T-4 minutes)   
  • ICPS LOX terminate replenish (T-3 minutes, 30 seconds)  
  • ICPS switches to internal battery power (T-1 minute, 56 seconds)  
  • Core stage switches to internal power (T-1 minute, 30 seconds)  
  • ICPS enters terminal countdown mode (T-1 minute, 20 seconds)  
  • ICPS LH2 terminate replenish (T-50 seconds)  
  • Ground launch sequencer sends “Go for automated launch sequencer” command (T-33 seconds)  
  • Core stage flight computer to automated launching sequencer (T-30 seconds)  
  • Ground launch sequencer manual cut-off at T-9.34 seconds 

Proceed with Critical Safing Operations  

Proceed with Core Stage and ICPS Cryogenic Fuel Drain Operations 

NASA ‘Go’ for Artemis I Wet Dress Rehearsal

In a pre-test review on March 28, NASA gave the “go” to proceed with the Artemis I wet dress rehearsal scheduled for April 1-3. The approximately two-day test will run the Artemis I launch team through operations to load propellant into the rocket’s tanks, conduct a full launch countdown, demonstrate the ability to recycle the countdown clock, and also drain the tanks to give them an opportunity to practice the timelines and procedures they will use for launch.

During the rehearsal, controllers will count down to T-1 minutes and 30 seconds and pause to demonstrate the ability to hold for up to 3 minutes, then resume until 33 seconds before when launch would occur, then pause the countdown. Then they will recycle back to ten minutes before launch and conduct a second terminal countdown to approximately 9.3 seconds before launch, then end the countdown. Sometimes called a “scrub,” launch controllers may decide not to proceed with launch if a technical or weather issue arises during or prior to the countdown. At the end of the test, the team will drain the propellant to demonstrate the procedures that would be used during a launch scrub. After draining the tanks, the team will review the test data before setting an official target launch date.

NASA will provide a live video stream of the rocket and spacecraft at the launch pad beginning at Noon EDT on April 1 on the Kennedy Newsroom YouTube channel. In addition to updates on this blog, NASA also will provide operational updates on the Exploration Ground Systems Twitter account.

NASA Continues Artemis I Preparations at Pad Wet Dress Rehearsal Test

Following arrival of the Space Launch System rocket and Orion spacecraft for Artemis I at Launch Pad 39B at NASA’s Kennedy Space Center in Florida on March 18, teams have connected numerous ground support equipment elements to the rocket and spacecraft, including electrical, fuel environmental control system ducts, and cryogenic propellant lines. Teams successfully powered up all elements of the integrated system at the pad for the first time on March 21 in preparation for the wet dress rehearsal test planned for April 1-3.

Engineering testing is underway to ensure systems continue to operate as planned with the rocket and spacecraft now configured at the pad. Additionally, technicians will don self-contained atmospheric protective ensemble suits, or SCAPE suits, to practice operations in the event of an emergency at the pad during fueling and launch. After checkouts at the pad are complete next week, the team will start system walkdowns ahead of the test.

The approximately two-day wet dress rehearsal test will demonstrate the team’s ability to load cryogenic, or super-cold, propellants into the rocket, conduct a launch countdown, and practice safely removing propellants at the launch pad. After wet dress rehearsal, engineers will roll the rocket and spacecraft back to the Vehicle Assembly Building for final checkouts before launch.

Artemis I Moon Rocket Arrives at Launch Pad for First Time

NASA’s Space Launch System (SLS) rocket with the Orion spacecraft aboard is seen illuminated by spotlights atop a mobile launcher at Launch Complex 39B, Friday, March 18, 2022, after being rollout out to the launch pad for the first time at NASA’s Kennedy Space Center in Florida. Photo Credit: (NASA/Joel Kowsky)

Around 4:15 a.m. ET the Space Launch System rocket and Orion Spacecraft for the Artemis I mission arrived atop Launch Complex 39B after a nearly 11-hour journey from the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida.

In the coming days, engineers and technicians will prepare the Artemis I rocket for its final major test – the wet dress rehearsal. The approximately two-day test will demonstrate the team’s ability to load cryogenic, or super-cold, propellants into the rocket, conduct a launch countdown, and practice safely removing propellants at the launch pad.  After wet dress rehearsal, engineers will roll the rocket and spacecraft back to the Vehicle Assembly Building for final checkouts before launch.

NASA’s Moon Rocket Keeps on Rolling to Launch Complex 39B

NASA’s Space Launch System (SLS) rocket, with the Orion capsule atop, slowly rolls out of the Vehicle Assembly Building at the agency’s Kennedy Space Center in Florida on March 17, 2022, on its journey to Launch Complex 39B. Carried atop the crawler-transporter 2, NASA’s Moon rocket is venturing out to the launch pad for a wet dress rehearsal ahead of the uncrewed Artemis I launch. Credit: NASA

NASA’s mega-Moon rocket continues its four-mile journey to the launch pad after leaving the Vehicle Assembly Building after a planned stop to adjust the Crew Access Arm. Traveling at a top speed of .82 mph, the crawler-transporter with the Space Launch System rocket and Orion spacecraft atop the mobile launcher is on its way to Launch Complex 39B.

Once at the launch pad, the team will begin final preparations ahead of the wet dress rehearsal test.

NASA’s Moon Rocket Revealed Outside Vehicle Assembly Building

NASA’s Moon rocket is on the move at the agency’s Kennedy Space Center in Florida, rolling out of the Vehicle Assembly Building for a 4.2-mile journey to Launch Complex 39B on March 17, 2022. Carried atop the crawler-transporter 2, the Space Launch System (SLS) rocket and Orion spacecraft are venturing to the pad for a wet dress rehearsal ahead of the uncrewed Artemis I launch.
NASA’s Moon rocket is on the move at the agency’s Kennedy Space Center in Florida, rolling out of the Vehicle Assembly Building for a 4.2-mile journey to Launch Complex 39B on March 17, 2022. Carried atop the crawler-transporter 2, the Space Launch System (SLS) rocket and Orion spacecraft are venturing to the pad for a wet dress rehearsal ahead of the uncrewed Artemis I launch. Photo credit: NASA

The rocket and spacecraft for NASA’s Artemis I mission has fully left Kennedy Space Center’s Vehicle Assembly Building (VAB) for the first time on the way to Launch Complex 39B for a wet dress rehearsal test.

The team is in a planned pause outside the building to retract the Crew Access Arm (CAA). The arm interfaces with the Orion spacecraft stacked atop the Space Launch System (SLS) rocket to provide access to the Orion crew module during operations in the VAB and at the launch pad. On crewed Artemis missions beginning with Artemis II, the access arm also will provide entry and exit for astronauts and payloads that will fly aboard. Several days before the rollout began, the arm was moved closer to the rocket to fit through the VAB door. Engineers are extending it to lock it in its travel position.

Once the CAA retraction is complete, the team will continue the four-mile trek to Launch Complex 39B.

NASA’s Mega Moon Rocket Begins Rolling to Launch Pad

NASA’s Space Launch System (SLS) rocket, with the Orion capsule atop, prepares to roll out of High Bay 3 of the Vehicle Assembly Building at the agency’s Kennedy Space Center in Florida on March 17, 2022, for its journey to Launch Complex 39B. Carried atop the crawler-transporter 2, NASA’s Moon rocket is venturing out to the launch pad for a wet dress rehearsal ahead of the uncrewed Artemis I launch.
NASA’s Space Launch System (SLS) rocket, with the Orion capsule atop, prepares to roll out of High Bay 3 of the Vehicle Assembly Building at the agency’s Kennedy Space Center in Florida on March 17, 2022, for its journey to Launch Complex 39B. Carried atop the crawler-transporter 2, NASA’s Moon rocket is venturing out to the launch pad for a wet dress rehearsal ahead of the uncrewed Artemis I launch. Photo credit: NASA/Kim Shiflett

The Space Launch System rocket and Orion spacecraft for the Artemis I mission are rolling to Launch Complex 39B at the Kennedy Space Center in Florida for the very first time. At about 5:45 p.m. ET, with the integrated SLS and Orion system atop it, the crawler-transporter began the approximately 4-mile, journey from the Vehicle Assembly Building (VAB) to the launch pad. Once outside the VAB high-bay doors, the Moon rocket will make a planned pause allowing the team to reposition the Crew Access Arm before continuing to the launch pad. The crawler-transporter will move slowly during the trek to the pad with a top cruising speed of .82 mph. The journey is expected to take between six and 12 hours.

After they arrive at the pad, engineers will prepare the integrated rocket and Orion spacecraft for a critical wet dress rehearsal test that includes loading all the propellants

Artemis I Stack Ready to Rock(et) and Roll

SLS rocket
In this view looking up in High Bay 3 of the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, all of the work platforms that surround the Artemis I Space Launch System (SLS) and Orion spacecraft are fully retracted on March 16, 2022. The Artemis I stack atop the mobile launcher will roll out to Launch Complex 39B atop the crawler-transporter 2 for a wet dress rehearsal ahead of launch. Photo credits: NASA/Glenn Benson

NASA’s new Moon rocket stands poised inside Kennedy Space Center’s iconic Vehicle Assembly Building ahead of its first journey to the launch pad. Comprised of NASA’s Space Launch System (SLS) rocket and Orion spacecraft, and sitting on its mobile launcher, the Artemis I Moon-bound rocket is ready to roll March 17 to Launch Complex 39B for its wet dress rehearsal test targeted to begin on April 1.

The dress rehearsal will demonstrate the team’s ability to load more than 700,000 gallons of cryogenic, or super-cold, propellants into the rocket at the launch pad, practice every phase of the launch countdown, and drain propellants to demonstrate safely standing down on a launch attempt. The test will be the culmination of months of assembly and testing for SLS and Orion, as well as preparations by launch control and engineering teams, and set the stage for the first Artemis launch.

The uncrewed Artemis I mission is the first flight of the SLS rocket and Orion spacecraft together. Future missions will send people to work in lunar orbit and on the Moon’s surface. With the Artemis missions, NASA will land the first woman and the first person of color on the Moon and establish long-term exploration in preparation for missions to Mars. SLS and Orion, along with the commercial human landing system and the Gateway that will orbit the Moon, are NASA’s backbone for deep space exploration.

Live coverage for rollout begins at 5 p.m. EDT and will include live remarks from NASA Administrator Bill Nelson and other guests. Coverage will air on NASA Television, the NASA app, and the agency’s website.

Live, static camera views of the debut and arrival at the pad will be available starting at 4 p.m. EDT on the Kennedy Newsroom YouTube channel.