Teams have resumed the flow of liquid hydrogen into the core stage after warming up the quick disconnect, or interface where the fuel feed line connects to the rocket, to reseat the connection as part of their troubleshooting plan to fast fill the propellant.
Tag: Space Launch System
Artemis Cryogenic Test: Core Stage LOX Fast Fill Underway, Proceeding Toward LH2 Slow Fill
Fast fill is underway for the Space Launch System (SLS) rocket’s core stage liquid oxygen (LOX) tank. Next, teams will transition from slow fill to fast fill for the liquid hydrogen (LH2) tank and initiate, or “kick start,” the engine bleed, which will begin flowing supercold LH2 to start cooling the four RS-25 engines down to the temperature conditions required for launch.
Follow along with live coverage and with the countdown milestones for the cryogenic demonstration test ahead of the Artemis I mission.
Weather Remains 60% Favorable for Artemis I Launch, Sept 3.
Following the Artemis I pre-launch briefing, meteorologists with the U.S. Space Force Space Launch Delta 45 predict a 60% chance of favorable weather conditions at the beginning of the two-hour launch window that opens at 2:17 p.m. EDT Sept 3, increasing to an 80% chance of favorable weather conditions toward the later part of the window. The primary weather concern for the two-hour launch window remains scattered rain showers. The weather guidelines for NASA’s Artemis I flight test identify conditions to launch the agency’s Space Launch System (SLS) and Orion spacecraft.
Teams will continue working their way through the countdown conducting planned health checks on SLS and Orion systems. The mission management team will meet early in the morning, Saturday, Sept. 3 and give the final determination for a “go” or “no-go” decision to begin tanking operations.
The uncrewed flight test will test SLS and Orion as an integrated system, demonstrating the performance of the rocket and testing the spacecraft’s capabilities as it journeys about 40,000 miles beyond the Moon over the course of about six weeks.
The first in an increasingly complex series of missions, Artemis I will pave the way for long-term lunar exploration, providing the foundation for extending human presence to the Moon and beyond.
Live coverage will begin on NASA television on the agency’s website and the NASA app at 5:45 a.m. with commentary and views of the rocket during tanking operations. Full launch coverage begin at 12:15 p.m. EDT on NASA Television and the agency’s website, as well as YouTube, Twitter, Facebook, LinkedIn, Twitch, Daily Motion, Theta.TV, and the NASA app. NASA en espanol broadcast coverage will begin at 1 p.m. EDT.
Launch Director Gives “Go” to Begin Cryogenic Operations, NASA TV Coverage Underway
Artemis Launch Director Charlie Blackwell-Thompson has given the “go” to officially begin loading propellants into the Space Launch System rocket. The launch weather officer now reports there are no indication of lightning within five nautical miles of Launch Pad 39B. Tanking begins with chilldown of the core stage liquid oxygen transfer line.
NASA TV coverage is underway at http://www.nasa.gov/live.
Mission Management Team “Go” to Proceed with Tanking for Artemis I Mission
The Artemis I Mission Management Team has given the “go” to proceed toward tanking operations.
Weather conditions remain 80% favorable at the beginning of the two-hour launch window which opens at 8:33 a.m. EDT Aug. 29, with chances for rain showers increasing toward the later part of the window.
Artemis I launch director Charlie Blackwell-Thompson is scheduled to give the “go” to officially begin propellant loading operations just before midnight.
During tanking operations, teams will fuel the Space Launch System (SLS) rocket with liquid oxygen (LOX) and liquid hydrogen (LH2), beginning with the rocket’s core stage and then the interim cryogenic propulsion stage.
Tanking begins with chilling down the LOX lines for the core stage. The process for the chill down, or cooling, uses the propellant lines to load the rocket’s core stage LOX in preparation for tanking. The LOX tank holds 196,000 gallons of liquid oxygen, cooled to minus 297 degrees Fahrenheit. In sequential fashion, LOX and LH2 will flow into the rocket’s core stage tank and be topped off and replenished as some of the cryogenic propellant boils off.
The process involves slowly filling the core stage with propellant to thermally condition the tank until temperature and pressure are stable before beginning fast fill operations, which is when the tank is filled at a quicker pump speed. As the super cold liquid oxygen fills the core stage tank, some venting may be visible. The team also will conduct leak checks to ensure propellant loading is proceeding as expected.
At midnight, NASA TV coverage begins with commentary of tanking operations to load propellant into the SLS rocket. Full coverage begins at 6:30 a.m. in English and at 7:30, coverage in Spanish begins.
Below are the countdown milestones as planned for tanking:
- Core Stage LO2 transfer line chilldown (L-8H15M – L-8H)
- Core stage LO2 main propulsion system (MPS) chilldown (L-8H – L-7H20M)
- Core stage LO2 slow fill (L-7H20M – L-7H5M)
- Core Stage LO2 fast fill (L-7H5M – L-4H15M)
- Core Stage LH2 chilldown (L-7H15M – L-7H5M)
- Core Stage LH2 slow fill start (L-7H5M – L-6H15M)
- Core Stage LH2 fast fill (L-6H15M – L-5H5M)
- Core Stage LH2 topping (L-5H5M – L-5H)
L-5 hours and counting
- Core Stage LH2 replenish (L-5H – Launch)
- ICPS LH2 ground support equipment (GSE) and tank chilldown (L-4H45M – L-4H30M)
- ICPS LH2 fast fill start (L-4H30M – L-3H30M)
- Orion communications system activated (RF to Mission Control) (L-4H20M – L-3H45M)
- Core stage LO2 topping (L-4H15M– L-3H55M)
- Core Stage LO2 replenish (L-3H55M – Launch)
- ICPS L02 MPS chilldown (L-3H55M– L-3H45M)
- ICPS L02 fast fill (L-3H45M– L-2H55M)
- ICPS LH2 validation and leak test (L-3H30M – L-3H15M)
- ICPS LH2 tank topping start (L-3H15M – L-2H55M)
L-3 hours and counting
- ICPS/Space Launch System (SLS) telemetry data verified with Mission Control and SLS Engineering Support Center (L-2H55M – L-2H45M)
- ICPS LO2 validation and leak test (L-2H55M – L-2H30M)
- ICPS LH2 replenish (L-2H50M – Launch)
- ICPS LO2 topping (L-2H30M – L-2H10M)
- ICPS LO2 replenish (L-2H10M – Launch)
Artemis I Update: Rocket’s Upper Stage Powered Up, Countdown on Track
The Space Launch System rocket’s interim cryogenic propulsion stage (ICPS) has been powered up, the NASA test director has given the “go” for booster power up, and all non-essential personnel have left the launch pad area in preparation for propellant loading operations.
At 10:53 p.m. EDT, or L-9 hours, 40 minutes, the launch team is expected to reach a planned two hour, 30-minute built-in hold. During this time, the mission management team will review the status of operations, receive a weather briefing, and make a “go” or “no-go” decision to proceed with tanking operations.
Tanking milestones include filling the rocket’s core stage with several hundred thousand gallons of liquid oxygen and liquid hydrogen. This will occur over a series of different propellant loading milestones to fill and replenish the tanks.
At midnight, NASA TV coverage begins with commentary of tanking operations to load propellant into the SLS rocket. Full coverage begins at 6:30 a.m.
Artemis I Moon Rocket Arrives at Launch Pad Ahead of Historic Mission

Around 7:30 a.m. EDT the Space Launch System rocket and Orion spacecraft for the Artemis I mission arrived atop Launch Complex 39B at NASA’s Kennedy Space Center in Florida after a nearly 10-hour journey from the Vehicle Assembly Building.
In the coming days, engineers and technicians will configure systems at the pad for launch, which is currently targeted for no earlier than Aug. 29 at 8:33 a.m. (two hour launch window). Teams have worked to refine operations and procedures and have incorporated lessons learned from the wet dress rehearsal test campaign and have updated the launch timeline accordingly.
NASA’s Mega Moon Rocket Begins Roll to Launch Pad
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 ahead of launch, currently targeted for Aug. 29. At about 10 p.m. EDT the crawler-transporter began the approximately 4-mile, journey from the Vehicle Assembly Building (VAB) to Launch Pad 39B.
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 journey is expected to take between eight and 12 hours. NASA will provide an update once the rocket has arrived at the launch pad.
Artemis I Moon Rocket Ready to Roll to the Launch Pad
Engineers and technicians at NASA’s Kennedy Space Center in Florida have completed the final testing and checkouts of the Artemis I Moon rocket ahead of rolling to Launch Pad 39B. NASA is targeting as soon as 9 p.m. EDT of Tuesday, Aug. 16 for rollout ahead of a targeted Aug. 29 launch.
The crawler-transporter will roll inside the Vehicle Assembly Building (VAB) and under the Space Launch System rocket and Orion spacecraft later today. Teams are currently working to prepare the integrated stack for rollout.
Over the weekend the team completed testing of the flight termination system, which marked the final major activity prior to closing out the rocket and retracting the final access platforms in the VAB.
The agency will provide a live stream of the rollout beginning at 3 p.m. EDT Tuesday, Aug. 16 on the NASA Kennedy You Tube channel.
Teams Work Final Preparations for Roll Out of Artemis I Moon Rocket

Engineers are conducting the last integrated test before the Space Launch System (SLS) rocket and Orion spacecraft roll out to Launch Pad 39B next week for the launch of the Artemis I flight test. This week, teams began the second part of the flight termination system (FTS) test. The first part of the test was conducted earlier this year prior to the wet dress rehearsal.
For safety purposes, all rockets are required to have a system that the Space Launch Delta 45 can use to terminate the flight if necessary. Following completion of the FTS testing, the Eastern Range requires SLS to launch within a certain timeframe. In order to meet the Aug. 29 launch attempt and backup attempts on Sept. 2 and 5, NASA has received an extension from the Space Launch Delta 45 on the validation of the FTS from 20 to 25 days before the system would need to be retested. The waiver will be valid throughout the Artemis I launch attempts.
Once the flight termination system testing is complete, teams will complete final closeouts on SLS and Orion before it rolls out of the Vehicle Assembly Building, including closing out the core stage and solid rocket boosters and retracting the remaining access platforms. The Orion crew module and launch abort system hatches were closed earlier this week, and Orion is in the final preparations for roll.
The Matroshka AstroRad Radiation Experiment torsos, Helga and Zohar, outfitted with sensors to measure radiation levels future crew will be exposed to, have joined Commander Campos and are now installed inside the Orion spacecraft. The final payloads, including the agency’s Biology Experiment-1, will be installed once the rocket and spacecraft are at the pad for launch.
The agency is targeting Thursday, Aug. 18 to roll SLS and the Orion spacecraft to the spaceport’s Launch Pad 39B and will provide a live stream beginning at 6 p.m. EDT Wednesday, Aug. 17 on the NASA Kennedy You Tube channel.