With the Artemis I Space Launch System rocket and Orion spacecraft safety in the Vehicle Assembly Building after rolling back from Launch Pad 39B Monday night, NASA continues to prioritize its employees as Hurricane Ian approaches the Kennedy Space Center area.
As part of NASA’s hurricane preparedness protocol, a “ride out” team will remain in a safe location at Kennedy throughout the storm to monitor centerwide conditions. After the storm passes, they will conduct an assessment of facilities, property, and equipment. Once it is safe for additional employees to return to Kennedy, engineers will extend platforms to establish access to the rocket and spacecraft.
Managers will review options on the extent of work that will be conducted in the VAB before returning to the launch pad or identifying the next opportunity for launch. Technicians will swap out batteries on the rocket’s flight termination system and retest the system prior to the next launch attempt.
NASA will roll the Artemis I Space Launch System rocket and Orion spacecraft back to the Vehicle Assembly Building on Monday, Sept. 26. First motion is targeted for 11 p.m. EDT.
Managers met Monday morning and made the decision based on the latest weather predictions associated with Hurricane Ian, after additional data gathered overnight did not show improving expected conditions for the Kennedy Space Center area. The decision allows time for employees to address the needs of their families and protect the integrated rocket and spacecraft system. The time of first motion also is based on the best predicted conditions for rollback to meet weather criteria for the move.
NASA has continued to rely on the most up to date information from the National Oceanic and Atmospheric Administration, U.S. Space Force, and the National Hurricane Center throughout its evaluations and continues to closely monitor conditions for the Kennedy area.
NASA continues to provide a live stream of the rocket and spacecraft on the launch pad.
The launch director has confirmed all objectives have been met for the cryogenic demonstration test, and teams are now proceeding with critical safing activities and preparations for draining the rocket’s tanks. After encountering a hydrogen leak early in the loading process, engineers were able to troubleshoot the issue and proceed with the planned activities.
The four main objectives for the demonstration included assessing the repair to address the hydrogen leak identified on the previous launch attempt, loading propellants into the rocket’s tanks using new procedures, conducting the kick-start bleed, and performing a pre-pressurization test. The new cryogenic loading procedures and ground automation were designed to transition temperature and pressures slowly during tanking to reduce the likelihood of leaks that could be caused by rapid changes in temperature or pressure. After encountering the leak early in the operation, teams further reduced loading pressures to troubleshoot the issue and proceed with the demonstration test. The pre-pressurization test enabled engineers to calibrate the settings used for conditioning the engines during the terminal count and validate timelines before launch day to reduce schedule risk during the countdown on launch day.
Teams will evaluate the data from the test, along with weather and other factors, before confirming readiness to proceed into the next launch opportunity. The rocket remains in a safe configuration as teams assess next steps.
As the countdown continued Tuesday toward the cryogenic demonstration test, teams conducted final closeouts at the pad and performed other preparations for the test. Work will continue through the night, and all non-essential personnel will leave Launch Pad 39B by 3:40 a.m. EDT Wednesday. The launch director is expected to give a “go” to begin loading cryogenic propellants into the rocket at approximately 7 a.m. Although the countdown clock is ticking down to a simulated liftoff time of 3:40 p.m., the test is planned to conclude around 3 p.m. after the teams have met the objectives and will not go into the terminal count phase of the launch countdown. Teams may extend the duration of the test should circumstances warrant it.
The launch countdown contains “L Minus” and “T Minus” times. “L minus” indicates how far away we are from liftoff in hours and minutes. “T minus” time is a sequence of events that are built into the launch countdown. Pauses in the countdown, or “holds,” are built into the countdown to allow the launch team to target a precise launch window, and to provide a cushion of time for certain tasks and procedures without impacting the overall schedule. During planned holds in the countdown process, the countdown clock is intentionally stopped and the T- time also stops. The L- time, however, continues to advance.
Below are some of the key events that take place at each milestone after the countdown begins.
L-9 hours, 40 minutes and counting
6 a.m.: Built in countdown hold begins (L-9H40M – L-7H10M)
6 a.m.: Launch team conducts a weather and tanking briefing (L-9H40M – L-8H50M)
7 a.m.: Launch team decides if they are “go” or “no-go” to begin tanking the rocket (L-8H40M)
7:25 a.m. Core Stage LOX transfer line chilldown (L-8H15M – L-8H)
L-8 hours and counting
7:40 a.m.: Core stage LOX main propulsion system (MPS) chilldown (L-8H – L-7H20M)
8:20 a.m.: Core stage LOX slow fill (L-7H20M – L-7H5M)
8:20 a.m.: Core Stage LH2 transfer line chilldown (L-7H20M – L-7H10M)
NASA remains on track for an Artemis I cryogenic demonstration test on Wednesday, Sept. 21. In the days since the previous launch attempt, teams have analyzed the seals that were replaced on an interface for the liquid hydrogen fuel line between the Space Launch System (SLS) rocket and the mobile launcher and adjusted procedures for loading cryogenic, or supercold, propellants into the rocket. Engineers identified a small indentation found on the eight-inch-diameter liquid hydrogen seal that may have been a contributing factor to the leak on the previous launch attempt.
With new seals, updated cryogenic procedures, and additional ground software automation, teams are now preparing to demonstrate the updates under the same cryogenic conditions the rocket will experience on launch day. During the demonstration, the four main objectives include assessing the repair to address the hydrogen leak, loading propellants into the rocket’s tanks using the new procedures, conducting the kick-start bleed, and performing a pre-pressurization test.
Based on recent engineering assessments, the new cryogenic loading procedures and ground automation will transition temperatures and pressures more slowly during tanking to reduce the likelihood of leaks that could be caused by rapid changes in temperature or pressure. After the liquid hydrogen tank transitions from the slow fill phase to fast fill, teams will initiate, or “kick-start,” the flow of liquid hydrogen through the engines to begin conditioning, or chilling them down, for launch. After both tanks have reached the replenish phase, the pre-pressurization test will bring the liquid hydrogen tank up to the pressure level it will experience just before launch while engineers calibrate the settings for conditioning the engines at a higher flow rate, as will be done during the terminal count. Performing the pressurization test during the demonstration will enable teams to dial-in the necessary settings and validate timelines before launch day, reducing schedule risk during the launch countdown.
Call to stations for the demonstration occurred at 5 p.m. EDT Monday. The launch director is expected to give a “go” to begin loading cryogenic propellants into the rocket at approximately 7 a.m. Wednesday. The test is planned to conclude around 3 p.m. after the teams have met the objectives and will not go into the terminal count phase of the launch countdown. Teams may extend the duration of the test should circumstances warrant it.
During the test, teams will load propellants into both the core stage and upper stage tanks, and Orion and the SLS boosters will remain unpowered. Meteorologists currently predict favorable weather for the test with a 15% chance of lightning within 5 nautical miles of the area, which meets criteria required for the test, and will continue to monitor expected conditions.
NASA Television will provide live coverage with commentary of the demonstration beginning at 7:15 a.m. Sept. 21. Continuous live video of the Artemis I rocket and spacecraft at Launch Pad 39B remains available on the Kennedy Newsroom YouTube Channel.
After disconnecting the ground and rocket-side plates on the interface, called a quick disconnect, for the liquid hydrogen fuel feed line, teams have replaced the seals on the Space Launch System rocket’s core stage associated with the liquid hydrogen leak detected during the Artemis I launch attempt Sept. 3.
Both the 8-inch line used to fill and drain liquid hydrogen from the core stage and the 4-inch bleed line used to redirect some of the propellant during tanking operations were removed and replaced this week.
Coming up, technicians will reconnect the umbilical plates and perform inspections over the weekend before preparing for a tanking demonstration as soon as Saturday, Sept. 17. This demonstration will allow engineers to check the new seals under cryogenic, or supercold, conditions as expected on launch day and before proceeding to the next launch attempt.
During the operation, teams will practice loading liquid hydrogen and liquid oxygen in the rocket’s core stage and interim cryogenic propulsion stage and getting to a stable replenish state for both propellants. Teams will confirm the leak has been repaired and also perform the kick-start bleed test and a pre-pressurization test, whichwill validate the ground and flight hardware and software systems can perform the necessary functions required to thermally condition the engines for flight. Following the test, teams will evaluate the data along with plans for the next launch opportunity.
Engineers are making progress repairing the area where a liquid hydrogen leak was detected during the Artemis I launch attempt Sept. 3, and NASA is preserving options for the next launch opportunity as early as Friday, Sept. 23.
Technicians constructed a tent-like enclosure around the work area to protect the hardware and teams from weather and other environmental conditions at Launch Pad 39B. They have disconnected the ground- and rocket-side plates on the interface, called a quick disconnect, for the liquid hydrogen fuel feed line, performed initial inspections, and began replacing two seals – one surrounding the 8-inch line used to fill and drain liquid hydrogen from the core stage, and another surrounding the 4-inch bleed line used to redirect some of the propellant during tanking operations. The SLS rocket and Orion spacecraft are in good condition while remaining at the launch pad.
Once the work is complete, engineers will reconnect the plates and perform initial tests to evaluate the new seals. Teams will check the new seals under cryogenic, or supercold, conditions no earlier than Sept. 17 in which the rocket’s core stage and interim cryogenic propulsion stage will be loaded with liquid oxygen and liquid hydrogen to validate the repair under the conditions it would experience on launch day. Engineers are in the process of developing a full plan for the checkouts.
NASA has submitted a request to the Eastern Range for an extension of the current testing requirement for the flight termination system. NASA is respecting the range’s processes for review of the request, and the agency continues to provide detailed information to support a range decision.
In the meantime, NASA is instructing the Artemis team to move forward with all preparations required for testing, followed by launch, including preparations to ensure adequate supplies of propellants and gases used in tanking operations, as well as flight operations planning for the mission. NASA has requested the following launch opportunities:
Sept 23: Two-hour launch window opens at 6:47 a.m. EDT; landing on Oct. 18
Sept. 27: 70-minute launch window opens at 11:37 a.m.; landing on Nov. 5
NASA’s teams internally are preparing to support additional dates in the event flexibility is required. The agency will evaluate and adjust launch opportunities and alternate dates based on progress at the pad and to align with other planned activities, including DART’s planned impact with an asteroid, the west coast launch of a government payload, and the launch of Crew-5 to the International Space Station.
Listen to a replay of today’s media teleconference on the status of the Artemis I mission. Artemis I is an uncrewed flight test to provide a foundation for human exploration in deep space and demonstrate our commitment and capability to extend human existence to the Moon and beyond.
After standing down on the Artemis I launch attempt Saturday, Sept. 3 due to a hydrogen leak, teams have decided to replace the seal on an interface, called the quick disconnect, between the liquid hydrogen fuel feed line on the mobile launcher and the Space Launch System (SLS) rocket while at the launch pad.
Performing the work at the pad requires technicians to set up an enclosure around the work area to protect the hardware from the weather and other environmental conditions, but enables engineers to test the repair under cryogenic, or supercold, conditions. Performing the work at the pad also allows teams to gather as much data as possible to understand the cause of the issue. Teams may return the rocket to the Vehicle Assembly Building (VAB) to perform additional work that does not require use of the cryogenic facilities available only at the pad.
To meet the current requirement by the Eastern Range for the certification on the flight termination system, NASA would need to roll the rocket and spacecraft back to the VAB before the next launch attempt to reset the system’s batteries.
Additionally, teams will also check plate coverings on other umbilical interfaces to ensure there are no leaks present at those locations. With seven main umbilical lines, each line may have multiple connection points.
Engineers are evaluating data gathered during the Artemis I launch attempt Monday, Aug. 29, when teams could not get the rocket’s engines to the proper temperature range required to start the engines at liftoff, and ran out of time in the two-hour launch window to continue. The mission management team will convene Tuesday afternoon to discuss the data and develop a plan forward.
The Space Launch System’s four RS-25 engines must be thermally conditioned before super cold propellant begins flowing through them for liftoff. Launch controllers condition them by increasing the pressure on the core stage liquid hydrogen tank to route, or “bleed” as it is often called, a portion of the approximately minus 423 F liquid hydrogen to the engines. Managers suspect the issue, seen on engine 3, is unlikely to be the result of a problem with the engine itself.
During the countdown, launch controllers worked through several additional issues, including storms in the area that delayed the start of propellant loading operations, a leak at the quick disconnect on the 8-inch line used to fill and drain core stage liquid hydrogen, and a hydrogen leak from a valve used to vent the propellant from the core stage intertank.
NASA will host a media teleconference Tuesday, Aug. 30, at approximately 6 p.m. EDT to provide an update on data analysis and discussions. The time is subject to change. While managers have not yet set a date for the next launch attempt, the earliest possible opportunity is Friday, Sept. 2, during a two-hour launch window that opens at 12:48 p.m.
After chilling the lines for liquid oxygen (LOX) and beginning with slow fill of the Space Launch System (SLS) rocket’s core stage, the team has now transitioned to LOX fast fill. Teams have also completed chilldown of the liquid hydrogen (LH2) lines and started LH2 slow fill.