Engineers have successfully repaired a liquid oxygen valve on the Space Launch System rocket’s core stage with subsequent checks confirming the valve to be operating properly. The team plans to power up the core stage for remaining functional checks later this week before moving forward with final preparations for a hot fire test in mid-March at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. NASA anticipates setting a target date for the hot fire next week.
Last week during checkouts for the second hot fire test, data indicated the valve (a type of valve called a pre-valve) was not working properly. The valve is part of the core stage’s main propulsion system and is opened at the beginning of the test and closed if necessary to stop the flow of liquid oxygen from the core stage propellant tank to the respective RS-25 engine during the hot fire.
While the valve was repaired over the weekend, the team continued to prepare the core stage, its four RS-25 engines, and the B-2 test stand for the second hot fire at Stennis. This hot fire test will be the last test before the Artemis I core stage is shipped to the agency’s Kennedy Space Center for assembly and integration with the rest of the rocket’s major elements and the Orion spacecraft.
NASA’s Space Launch System (SLS) solid rocket boosters have grown taller with the addition of the fifth and final pair of motor segments in preparation for the launch of Artemis I later this year. At NASA’s Kennedy Space Center in Florida, engineers with Exploration Ground Systems lowered the final solid rocket booster into place on the mobile launcher on Feb. 23. Up next, the nose assemblies will be placed atop the segments to complete the boosters. The twin boosters will power the first flight of the agency’s new deep space rocket during the launch of Artemis I. This mission is an uncrewed flight to test the SLS rocket and Orion spacecraft as an integrated system, preparing the way for Artemis II and other crewed flights to the Moon.
The Space Launch System (SLS) rocket’s interim cryogenic propulsion stage (ICPS) moved into the Multi-Payload Processing Facility February 18, 2021, at NASA’s Kennedy Space Center in Florida alongside one of its flight partners for the Artemis I mission, the Orion spacecraft. Both pieces of hardware will undergo fueling and servicing in the facility ahead of launch by teams from NASA’s Exploration Ground Systems and their primary contractor, Jacobs Technology. The rocket stage and Orion will remain close during their journey to space.
Built by United Launch Alliance and Boeing, the ICPS will be positioned above the core stage and will provide the power needed to give Orion the big push it needs to break out of Earth orbit on a precise trajectory toward the Moon during Artemis I.
This is the first time since the shuttle program that two pieces of flight hardware have been processed inside this facility at the same time. Once final checkouts are complete, the ICPS and Orion will part ways on the ground and be reunited in the Vehicle Assembly Building for integration onto the SLS rocket.
Artemis I will be an integrated flight test of the SLS rocket and Orion spacecraft ahead of the crewed flights to the Moon. Under the Artemis program, NASA will land the first woman and the next man on the lunar surface and establish a sustainable presence at the Moon to prepare for human missions to Mars.
NASA and Space Launch System (SLS) core stage prime contractor Boeing are thoroughly examining a liquid oxygen valve inside the stage’s engine section in order to identify repairs needed before a second hot fire with the Artemis I stage.
During preparations for the second hot fire, data indicated the valve was not opening correctly. Technicians installed platforms that allow engineers to access the valve inside the core stage engine section while the stage remains in the B-2 stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. After completion of troubleshooting, which will continue over the weekend, NASA will be in a better position to identify a potential date for the second hot fire test.
This valve, called a pre-valve, must be fully operational during hot fire testing. The valve is part of the core stage main propulsion system, and it helps deliver liquid oxygen propellant flowing from the liquid oxygen tank to an RS-25 engine. For the first hot fire on Jan. 16, all four liquid oxygen pre-valves performed as expected as did all four liquid hydrogen pre-valves.
The Green Run is a comprehensive series of tests for the SLS core stage before it launches the Artemis missions to the Moon, and the hot fire is the final and most intensive test. The Green Run tests have provided invaluable information on how the new rocket stage operates before it is used to launch the Artemis I mission.
NASA’s Artemis IOrion spacecraft is being outfitted with additional artwork as technicians began installing the logo for ESA (European Space Agency). ESA provided the European-built service module, which provides power and propulsion for the Orion spacecraft, and will also provide water and air for astronauts on future missions.
Artemis I extends NASA and ESA’s strong international partnership beyond low-Earth orbit to lunar exploration with Orion on Artemis missions. The ESA logo joins the historic NASA “meatball” insignia on the Artemis I spacecraft adapter jettison fairing panels that protect the service module during launch.
Orion is currently stationed at NASA’s Kennedy Space Center in the Multi-Payload Processing Facility, where it will undergo fueling and servicing by NASA’s Exploration Ground Systems and Jacobs Technology teams in preparation for the upcoming flight test with the Space Launch System rocket under the agency’s Artemis program.
NASA’s is reviewing the performance of a valve on the core stage of the Space Launch System rocket before proceeding with a second hot fire test at the agency’s Stennis Space Center near Bay St. Louis, Mississippi.
During checkout preparations over the weekend, engineers determined that one of eight valves (a type of valve called a prevalve) was not working properly. This valve is part of the core stage main propulsion system that supplies liquid oxygen to an RS-25 engine. During the first hot fire, all four liquid oxygen valves performed as expected as did the four liquid hydrogen valves. NASA and the core stage lead contractor Boeing will identify a path forward in the days ahead and reschedule the hot fire test that was originally scheduled for Feb. 25.
NASA is testing the new core stage on the ground to check out the operation of all systems before flight, as the agency has done with every new rocket stage ever flown. The core stage is the center core of the rocket that includes two propellant tanks and four RS-25 engines, miles of cables, all the avionics, electronics, computers – the brains of the rocket – and the plumbing that work together to launch the rocket during the first eight minutes of the mission. The Green Run test series is a comprehensive test of the core stage before it launches the Artemis missions to the Moon.
Check back at this blog for an update on the completion of the review and actions needed to resolve the issue, as well as the schedule for the hot fire test. For more information about SLS Green Run, visit https://www.nasa.gov/artemisprogram/greenrun
At the review, NASA, Boeing, the core stage lead contractor, and Aerojet Rocketdyne, the RS-25 engine prime contractor, gave the “go” for proceeding with the test at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. In the coming days, the team will conduct systems checkouts and final inspections to ensure the core stage, its four RS-25 engines and the Green Run software and stage controller are ready for the hot fire. Engineers plan to power up the core stage on Tuesday, Feb. 23 ahead of the hot fire. The first SLS core stage hot fire test on Jan. 16, the first time all four engines were ignited, provided the team with significant data that informed process and procedures for the upcoming test.
After the first SLS core stage hot fire test on Jan. 16 at NASA’s Stennis Space Center near Bay St. Louis, Mississippi, the team put the stand and core stage in a configuration so that the stage and stand could be refurbished. This involved installing platforms on the test stand so that technicians could inspect, access, and perform procedures on the hardware.
The team has now completed this refurbishment work and conducted a review referred to as “the break of configuration review” to transition the core stage hardware to the test configuration for the second hot fire test. During refurbishment, the team thoroughly inspected the stage, dried the four RS-25 engines, and made minor repairs to the engines and thermal protection system.
The team is also modifying and testing the Green Run software for the flight computers based on data from the first hot fire. The team adjusted parameters used by the software logic, which operating on the flight computers automatically monitors a variety of parameters and controls the test during the terminal countdown and after engine ignition. The updated Green Run software was tested in the systems integration test facility at NASA’s Marshall Space Flight Center in Huntsville, Alabama, which has avionics and flight computers identical to the ones in the core stage.
Now, the team is preparing the core stage, the B-2 Test Stand, and the Stennis Test Control Centers for the upcoming hot fire test targeted for the week of Feb. 21. A target date for the test will be announced next week. The core stage is flight hardware that will be used for the Artemis I mission.
This video, the Brains of NASA’s SLS Rocket explains how the SLS avionics system and flight software will work to control the rocket on the Artemis missions. The Green Run test is providing valuable data on how the Green Run test software, which is like the flight software, works with the core stage flight computers to control the rocket.
Booster stacking continues! The second to last set of segments for NASA’s Space Launch System (SLS) solid rocket boosters were placed on the mobile launcher inside the Vehicle Assembly Building at NASA’s Kennedy Space Center. Engineers with Exploration Ground Systems and Jacobs transported the segments from the Rotation, Processing and Surge Facility, where they have been since June. Once fully stacked, each booster will stand nearly 17 stories tall. The twin boosters will power the first flight of the agency’s new deep space rocket during the Artemis I mission. This uncrewed flight later this year will test the SLS rocket and Orion spacecraft as an integrated system ahead of crewed flights.
The twin boosters will power the first flight of the agency’s new deep space rocket on its first Artemis Program mission. Artemis I will be an uncrewed flight to test the SLS rocket and Orion spacecraft as an integrated system ahead of crewed flights.