Artemis I – Page 2

Green Run Update: Engineers Repair Valve for Mid-March Hot Fire Test

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.

Propellant barges docked near the B-2 Test Stand 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.

Please check back at this blog for an update on the date NASA is targeting for the second Green Run hot fire. For more information about SLS Green Run, visit https://www.nasa.gov/artemisprogram/greenrun

Green Run Update: NASA Inspecting Valve, Continuing Hot Fire Preparations

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.

In preparation for a second hot fire test, engineers are examining issues with a liquid oxygen valve inside the Space Launch System rocket’s core stage installed in the B-2 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi.

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.

Check back at this blog for an update on 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

Green Run Update: SLS Team Prepares Core Stage for Second Hot Fire Test

The core stage Green Run test team has completed refurbishment activities and is preparing the Space Launch System (SLS) rocket’s core stage and its four RS-25 engines for a second hot fire test.

After the first SLS core stage hot fire test on Jan. 16 at NASA 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.

For updates, please check this blog or the Green Run web site: https://www.nasa.gov/artemisprogram/greenrun

Green Run Update: NASA Proceeds With Plans for Second Hot Fire Test

NASA plans to conduct a second Green Run hot fire test as early as the fourth week in February with the Space Launch System (SLS) rocket’s core stage that will launch the Artemis I mission to the Moon. The Green Run is a comprehensive assessment of the rocket’s core stage prior to launching Artemis missions.

While the first hot fire test marked a major milestone for the program with the firing of all four RS-25 engines together for the first time for about a minute, it ended earlier than planned. After evaluating data from the first hot fire and the prior seven Green Run tests, NASA and core stage lead contractor Boeing determined that a second, longer hot fire test should be conducted and would pose minimal risk to the Artemis I core stage while providing valuable data to help certify the core stage for flight.

Inspections showed the core stage hardware, including its engines, and the B-2 test stand are in excellent condition after the first hot fire test, and no major repairs are needed to prepare for a second hot fire test at NASA’s Stennis Space Center in Bay St. Louis, Mississippi.

All SLS rockets use the same core stage design, so a second Green Run hot fire will reduce risk for not only Artemis I, but also for all future SLS missions. The Green Run series of tests is designed to certify the core stage design and verify that the new stage is ready for flight. The hot fire test is the final Green Run test and will provide valuable data that minimizes risk for American deep space exploration missions for years to come.

The Green Run team scrutinized data from the first hot fire test and determined that a second hot fire lasting approximately at least four minutes would provide significant data to help verify the core stage is ready for flight. A second hot fire test is planned for about eight minutes to simulate the amount of time it will take to send the rocket to space following launch. The Green Run wet dress rehearsal and first hot fire test completed several operations:

transitioning to the automated launch sequence operated by the core stage flight computer and Green Run software,
completing the terminal countdown sequence that is like the launch countdown
pressuring the tanks and delivering propellant to the engines and demonstrating performance of the core stage’s main propulsion system,
firing the engines at 109 percent power level, and
operating the thrust vector control system that steers the engines.

Conducting a second hot fire test will allow the team to repeat operations from the first hot fire test and obtain data on how the core stage and the engines perform over a longer period that simulates more activities during the rocket’s launch and ascent. To prepare for the second hot fire test, the team is continuing to analyze data from the first test, drying and refurbishing the engines, and making minor thermal protection system repairs. They are also updating conservative control logic parameters that resulted in the flight computer ending the first hot fire test earlier than planned. The team has already repaired the faulty electrical harness which resulted in a notification of a Major Component Failure on Engine 4. This instrumentation issue did not affect the engine’s performance and did not contribute to ending the first test early.

After the second hot fire test, it will take about a month to refurbish the core stage and its engines. Then, the Pegasus barge will transport the core stage to NASA’s Kennedy Space Center in Florida where it will be assembled with the other parts of the SLS rocket and the Orion spacecraft being prepared for the Artemis I launch later this year.

Green Run Update: Hot Fire Met Many Objectives, Test Assessment Underway

For the Green Run hot fire test on Jan. 16, NASA set out to acquire test data to support 23 detailed verification objectives. To satisfy the objectives, hot fire test data is used in combination with analysis and testing that has already been completed. These detailed verification objectives are used to certify the design of the Space Launch System rocket’s core stage.

The preliminary assessment indicates that the data acquired met the goals for a number of the 23 objectives, such as those related to activities prior to engine ignition. The initial assessment also indicates that data acquired partially met the goals for several additional of the 23 objectives related to simultaneous operations of four RS-25 engines.

NASA and its industry partners, Boeing and Aerojet Rocketdyne, are continuing to assess the extensive data from the test. As part of the planned near-term activities, they will complete the final assessment determining which objectives were fully met and which ones were partially met. They also are evaluating the value of acquiring additional test data and a longer run time to augment the existing analyses and data.

Currently, the SLS core stage can still be loaded with propellant and pressurized 20 more times for a total of 22 cycles. Rocket stages like the core stage are designed to be loaded with cryogenic propellant and pressurized a specific number of times. These are called cryogenic loading cycles. Before Green Run testing began, SLS had allocated nine cryogenic cycles for testing at NASA’s Stennis Space Center in Bay St. Louis, Mississippi and has used two of those during the hot fire and wet dress rehearsal, with seven cryogenic cycles remaining for additional testing. For the Artemis I Iaunch, NASA is preserving 13 of the remaining 20 cryogenic loading cycles. These can be used for multiple launch attempts, a wet dress rehearsal on the launch pad, and other activities that require propellant loading and tank pressurization.

One of the critical activities that must happen before either another hot fire test or launch is drying and refurbishment of the engines. That activity is underway. NASA is continuing to inspect the core stage and its RS-25 engines on the B-2 test stand, and initial inspections indicate the hardware is in excellent condition.

Hardware inspection and data assessment will continue and will inform NASA’s decision on whether to conduct a second Green Run test or proceed with shipping the core stage to Kennedy for integration with other SLS hardware in the Vehicle Assembly Building.

SLS core stage — This infographic explains more about the core stage and its massive liquid hydrogen and liquid oxygen tanks that hold more than 700,000 gallons of propellant.

For more updates, images and videos, check back at this blog or the Green Run web site: https://www.nasa.gov/artemisprogram/greenrun

NASA conducted a media briefing with several experts who support the Green Run team on Jan. 19, and a replay will be available for 30 days by dialing 888-566-0617.

Green Run Update: Engines Igniting as Hot Fire Gets Underway

The hot fire is underway for the Space Launch System (SLS) rocket core stage at NASA’s Stennis Space Center near Bay St. Louis, Mississippi.

Engine ignition began at approximately six tenths of a second before T-0, beginning with Engine 1, then Engines 3, 4, and 2 ignited in sequence a few hundredths of a second apart. The test is expected to last about 8 minutes and will include three different power levels for the engines, as well as two 30-second engine gimballing, or pivoting, movements to simulate flight steering commands. Depending on the rate propellant is burned the time is estimated to range from 485 to 493 seconds to simulate launch.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

Green Run Update: Hot Fire Test Targeted for within an Hour

The teams are now targeting a hot fire test for NASA’s Space Launch System (SLS) rocket core stage within an hour. The team has completed a successful pressurization demonstration and is evaluating the data to ensure they are ready to proceed.

Live coverage is underway on NASA Television and the agency’s website.

Teams began the countdown for the hot fire test earlier today. This is the eighth and final test in the Green Run testing series for the rocket’s core stage that will launch NASA’s Artemis I mission around the Moon. Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

Green Run Update: Test Team Gives “Go” To Proceed with Tanking

The test team conducted a pre-test briefing in the Test Control Center at the B test complex at NASA’s Stennis Space Center near Bay St. Louis, Mississippi, and gave a “go” to proceed with testing and to fill the propellant tanks.

Over the next several hours, the teams will monitor the systems and load more than 700,000 gallons of cryogenic, or supercooled, liquid oxygen and liquid hydrogen that will be fed to the four RS-25 engines.

The hot fire will last up to 8 minutes and is scheduled to take place during a two-hour window that begins at 5 p.m. EST. Live coverage will begin at 4:20 p.m. EST on NASA Television and the agency’s website.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

SLS core stage This infographic provides information on the core stage including its two large propellant tanks.

Green Run Update: Preparations for Hot Fire Test Continue on Schedule

Preparations for conducting the final Green Run test for NASA’s Space Launch System (SLS) rocket are proceeding as planned, and the core stage is on schedule for a hot fire test tomorrow igniting all four of its RS-25 engines.

NASA is targeting a two-hour test window that opens at 5 p.m. EST Saturday, Jan.16, for the hot fire test at the agency’s Stennis Space Center near Bay St. Louis, Mississippi. Live coverage will begin at 4:20 p.m. on NASA Television and the agency’s website, followed by a post-test briefing approximately two hours after the test concludes.

The hot fire is the eighth and final test of the Green Run series to ensure the core stage of the SLS rocket is ready to launch Artemis missions to the Moon, beginning with Artemis I. The core stage includes the liquid hydrogen tank and liquid oxygen tank, four RS-25 engines, and the computers, electronics, and avionics that serve as the “brains” of the rocket. During the test, engineers will power up all the core stage systems, load more than 700,000 gallons of cryogenic, or supercold, propellant into the tanks, and fire all four engines at the same time to simulate the stage’s operation during launch, generating 1.6 million pounds of thrust.

Learn more about Green Run, and check back at this blog for updates on the SLS core stage hot fire test.

This video explains exactly how NASA and its partners, core stage lead contractor Boeing, and RS-engines lead contractor, Aerojet Rocketdyne are bringing each part of the core stage to life for the Green Run hot fire test.

SLS Team Completes Propellant Loading of Core Stage During Green Run Test

NASA and Boeing engineers successfully completed propellant loading during the seventh core stage Green Run test, wet dress rehearsal Sunday, Dec. 20. The massive Space Launch System (SLS) rocket’s tanks were loaded with more than 700,000 gallons of liquid hydrogen and liquid oxygen.

Engineers working in the Test Control Center monitored all core stage systems during the test as propellant flowed from six barges into the core stage in the B-2 Test Stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. First looks at the data indicate the stage performed well during the propellant loading and replenish process. Part of the test was to simulate the countdown with the tanks loaded, leading up to 33 seconds prior to the engines firing. However, the test ended a few minutes short of the planned countdown duration.

The core stage and the B-2 test stand are in excellent condition, and it does not appear to be an issue with the hardware. The team is evaluating data to pinpoint the exact cause of the early shutdown. Then they will decide if they are ready to move forward with the final test, a hot fire when all four engines will be fired simultaneously.

For more updates, visit this blog or the Green Run web site: https://www.nasa.gov/artemisprogram/greenrun