Technicians at NASA’s Michoud Assembly Facility in New Orleans have installed the first of four RS-25 engines on the core stage of the agency’s SLS (Space Launch System) rocket that will help power NASA’s first crewed Artemis mission to the Moon. During Artemis II, NASA astronauts Reid Wiseman, Victor Glover, Christina Koch, and CSA (Canadian Space Agency) astronaut Jeremy Hansen will launch on SLS and journey around the Moon inside the Orion spacecraft during an approximately 10-day mission in preparation for future lunar missions.
The Sept. 11 engine installation follows the joining of all five major structures that make up the SLS core stage earlier this spring. NASA, lead RS-25 engines contractor Aerojet Rocketdyne, an L3 Harris Technologies company, and Boeing, the core stage lead contractor, will continue integrating the remaining three engines into the stage and installing the propulsion and electrical systems within the structure.
All four RS-25 engines are located at the base of the core stage within the engine section, which protects the engines from the extreme temperatures during launch and has an aerodynamic boat tail fairing to channel airflow. During launch and flight, the four engines will fire nonstop for over eight minutes, consuming propellant from the core stage’s two massive propellant tanks at a rate of 1,500 gallons (5,678 liters) per second.
Each SLS engine has a different serial number. The serial number for the engine installed Sept. 11 in position two on the core stage is E2059. It along with the engine in position one, E2047, previously flew on space shuttle flights. E2047 is the most veteran engine of the entire set flying on Artemis II with 15 shuttle flights, including STS-98, which delivered the Destiny Laboratory Module to the International Space Station in 2001. The engines installed in positions three and four (E2062 and E2063) are new engines that include previously flown hardware.
NASA is working to land the first woman and first person of color on the Moon under Artemis. SLS is part of NASA’s backbone for deep space exploration, along with Orion and the Gateway in orbit around the Moon, and commercial human landing systems. SLS is the only rocket that can send Orion, astronauts, and supplies to the Moon in a single mission.
With approximately one month until NASA’s first launch attempt for the Artemis I mission, teams move closer to finishing operations for the Space Launch System (SLS) rocket and Orion spacecraft in the Vehicle Assembly Building at the agency’s Kennedy Space Center in Florida. NASA is currently targeting launch for no earlier than Monday, Aug. 29, at 8:33 a.m. EDT during a 2 hour window. A successful launch on Aug. 29 would result in a mission duration of about 42 days, returning Monday, Oct. 10. Engineers continue to progress through first time operations and are prepared learn and adapt along the way. Teams have planned accordingly with additional launch opportunities on Sept. 2 and Sept. 5 if more than one launch attempt is needed.
Engineers successfully reconnected the hydrogen tail service mast umbilical where a hydrogen leak was detected during the last wet dress rehearsal test. Teams tested the connection and did not detect any leaks under ambient conditions in the Vehicle Assembly Building. Up next, technicians will perform additional work to return the section to its launch configuration.
Technicians finished installing the rocket’s flight batteries. As part of operations to prepare the flight termination system, engineers installed and tested the core stage flight command receiver decoders and also tested the solid rocket boosters’ automatic destruct units. Work continues to complete installation of the thermal protection system blankets on the interim cryogenic propulsion stage and launch vehicle stage adapter. Following completion of the upper stage closeout work, teams will conduct flight closeout inspections, which includes removing access platforms and installing flight doors replacing the ground support equipment coverings on the core stage.
Teams also are replacing the inflatable seal between the mobile launcher’s crew access arm and Orion’s launch abort system after it experienced some minor damage due to inclement weather sustained while it was out at launch pad 39B for the wet dress rehearsal tests. The seal prevents anything from the outside environment from getting inside the capsule. Once the seal is replaced and tested, engineers will finish installing remaining payloads inside the crew module before SLS and Orion roll back out to the pad for launch.
Since returning to the Vehicle Assembly Building (VAB), ground systems teams have worked to prepare the Artemis I Space Launch System (SLS) rocket and Orion spacecraft to roll back to Launch Pad 39B in late May to complete the wet dress rehearsal test in the early to mid-June timeframe.
Inside the VAB at NASA’s Kennedy Space Center, engineers replaced a faulty helium check valve on the interim cryogenic propulsion stage that was identified after the second wet dress rehearsal attempt. Engineers have inspected the valve and found a small piece of rubber that prevented the valve from sealing correctly. Teams are looking at possible sources of the debris, but did not see any issues with the valve itself, and plan to test the newly installed valve later this week to confirm it is operating as expected.
Engineers also performed tests to address a hydrogen leak on one of two tail service mast umbilicals between the mobile launcher and the rocket. These umbilicals provide liquid oxygen and liquid hydrogen propellants, as well as electrical connections, from the mobile launcher to the rocket’s core stage during the launch countdown. Teams conducted leak checks on all the joints and tightened several flange bolts, or fasteners that act as a washer to increase the compression strength, that can loosen over time and were the most likely source of the leak. Teams re-tightened the flange bolts on the liquid hydrogen, liquid oxygen, and core stage intertank umbilicals. Engineers have not detected leaks in subsequent testing at ambient air temperature, and will continue to monitor for leaks when loading the super cold propellants at the launch pad.
The supplier that provides gaseous nitrogen for operations during tanking is upgrading its facility to meet the requirements for the next wet dress rehearsal attempt and the Artemis I launch. Teams are on track to complete the work early next week, followed by testing to ensure the system is ready for tanking. During the test, teams pump gaseous nitrogen into dry structures to protect avionics during propellant loading.
Once all major work is completed, teams will retract the working platforms and prepare the integrated SLS rocket and the Orion spacecraft for the second journey to the launch pad. NASA will announce dates for roll to the pad and the next wet dress rehearsal attempt once work is nearing completion inside the VAB.
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’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.
The first two of 20 platforms surrounding the Space Launch System (SLS) and Orion spacecraft that allow work on the integrated system inside the building were retracted for roll out to Launch Complex 39B. Teams retracted the platforms, which move like hydraulic kitchen drawers, near the launch abort system on the Orion spacecraft in anticipation of the roll.
Teams are continuing to install instrumentation on the SLS’s twin solid rocket boosters inside the VAB. Thousands of sensors and special instruments will monitor the rocket and spacecraft as they roll out for the first time on March 17 and make the four-mile journey to Launch Complex 39B, arriving on March 18. Engineers will capture as much data as possible on the performance of all the systems that are part of the rocket, spacecraft, ground systems used for rollout, and on the pad for propellant loading and other activities. Once all the rocket and spacecraft systems are inspected, the 322-foot-tall rocket will roll to the launch pad for the wet dress rehearsal test, which is scheduled to occur approximately two weeks after it arrives to 39B.
The last steps remaining before rollout include inspecting each piece of the rocket and spacecraft, including physically entering different components of SLS and, step-by-step, making sure SLS and Orion are ready for the trip to the launch pad. As inspections continue, the Kennedy ground systems team is working to remove equipment and scaffolding away from the rocket and will continue retracting the platforms until the entire rocket is revealed.
Since replacing an engine controller on RS-25 engine number four that is on the Space Launch System (SLS) rocket core stage, NASA, and lead engines contractor Aerojet Rocketdyne, have performed a series of tests to ensure the engines and controllers are ready to support the Artemis I mission. All four engine controllers performed as expected during power up, as part of the Artemis I Core Stage engineering tests.
Aerojet Rocketdyne and its manufacturer of the engine flight controller, conducted numerous tests on the faulty engine four controller and determined the cause to be a faulty memory chip. The device is used only during the controller start-up sequence and has no impact on controller operations beyond that point. There is no indication of faulty memory chips on the other three engines, and therefore no related constraints to the wet dress rehearsal or launch.
Kennedy teams are completing remaining SLS pre-flight diagnostic tests and hardware closeouts, including testing the flight termination system on the SLS and installing instrumentation on the twin solid rocket boosters, in advance of rolling the rocket and spacecraft to Launch Pad 39B for the first time next month for a final test before launch. This final test, known as the wet dress rehearsal, will run the launch team through operations to load propellant into the rocket’s tanks and conduct a full launch countdown.
During the test at the launch pad, engineers will be on duty in the Launch Control Center and in other stations where they will work during the Artemis I launch. They will capture as much data as possible on the performance of all the systems that are part of SLS and the Orion spacecraft as well as the Kennedy ground systems. NASA will set a target launch date after a successful wet dress rehearsal test.
This week, engineers and technicians successfully completed an engineering test series of the Space Launch System (SLS) rocket core stage inside the Vehicle Assembly Building at NASA’s Kennedy Space Center as part of the integrated testing before launch.
After replacing and testing one of four RS-25 engine controllers, the team conducted several tests to ensure the massive core stage is ready to roll to the launch pad for the wet dress rehearsal ahead of the Artemis I launch. Engineers and technicians tested communication between the flight computers and other core stage systems and slightly moved the engines to practice the gimbaling they will experience during flight.
All four engine controllers were powered up and performed as expected as part of the Artemis I Core Stage engineering tests. Following the power up, engineers successfully performed diagnostic tests on each controller.
Up next, the team will conduct a second countdown sequencing test to demonstrate the ground launch software and ground launch sequencer, which checks for health and status of the vehicle while at the pad. The simulated launch countdown tests the responses from SLS and the Orion spacecraft, ensuring the sequencer can run without any issues. After the countdown test and final closeouts are complete, SLS and Orion will head to the launch pad for the first time to complete the wet dress rehearsal test.
Final stacking operations for NASA’s mega-Moon rocket are underway inside the Vehicle Assembly Building at NASA’s Kennedy Space Center as the Orion spacecraft is lifted onto the Space Launch System (SLS) rocket for the Artemis I mission. Engineers and technicians with Exploration Ground Systems (EGS) and Jacobs attached the spacecraft to one of the five overhead cranes inside the building and began lifting it a little after midnight EDT.
Next, teams will slowly lower it onto the fully stacked SLS rocket and connect it to the Orion Stage Adapter. This will require the EGS team to align the spacecraft perfectly with the adapter before gently attaching the two together. This operation will take several hours to make sure Orion is securely in place.
NASA will provide an update once stacking for the Artemis I mission is complete.
Teams at NASA’s Kennedy Space Center in Florida are putting the final touches on the Orionspacecraft for the Artemis I mission by connecting the ogive fairings for the launch abort system (LAS) assembly. Pronounced oh-jive, the ogive fairings consist of four protective panels, and their installation will complete the LAS assembly.
Technicians and engineers from the center’s Exploration Ground Systems and contractor Jacobs recently finished attaching the launch abort tower to the top of the Orion crew module. They then began lifting and mating the lightweight fairings, which will shield the crew module from the severe vibrations and sounds it will experience during launch. One of the fairing panels has a hatch to allow access to the crew module before launch.
During Artemis missions, the 44-foot-tall LAS will detach from the spacecraft when it is no longer needed, shortly after launching on the Space Launch System (SLS) rocket, to lighten the journey to the Moon. Although the abort motors will not be active on the uncrewed Artemis I flight test, the system is intended to protect astronauts on future missions if a problem arises during launch or ascent by pulling the spacecraft away from a failing rocket.
Once LAS installation is complete, the spacecraft will leave the Launch Abort System Facility and continue on its path to the pad, making its way to the spaceport’s Vehicle Assembly Building to be integrated with the SLS rocket ahead of the launch.