posted 10-12-2016 11:30 AM               

A test version of the Space Launch System (SLS) launch vehicle stage adapter, or LVSA, is being readied to load into a 65-foot-tall test stand at NASA's Marshall Space Flight Center. The LVSA will connect two major sections of the upper part of SLS — the core stage and the interim cryogenic propulsion stage (ICPS) — for the first flight of the rocket and NASA's Orion Spacecraft.

The LVSA joins the core stage simulator in the stand, and several other pieces of test hardware will be added to the stack later this fall for structural loads testing. The rigorous test series will ensure each structure can withstand the incredible stresses of launch.

posted 10-12-2016 03:39 PM               

The Pressure is On for SLS Hardware in Upcoming Test

Engineers are getting ready to put the pressure on hardware for the world's most powerful rocket, NASA's Space Launch System, as part of a rigorous test series to ensure each structure can withstand the incredible stresses of launch. SLS and the agency's Orion spacecraft will travel to new destinations in deep space as NASA continues to prepare for its Journey to Mars.

"Not only is this series more cost effective by testing several qualification articles together, but it also helps us to understand how the flight-like hardware will interface together," said Mike Roberts, mechanical team lead in the Engineering Directorate at NASA's Marshall Space Flight Center in Huntsville, Alabama.

A 65-foot-tall test stand at Marshall is being readied for the upcoming test series, where two simulators and four qualification articles of the upper part of the SLS will be stacked and then pushed, pulled and twisted by forces similar to those experienced in flight. "We have to make sure all the hardware is structurally sound and will not compromise under the incredible amounts of force," said Dee VanCleave, lead test engineer for the structural loads test at Marshall. "The best way to verify these major structures are ready for launch is to test them."

The qualification articles and simulators will be stacked in order from bottom to top in a test structure with "spiders" – given that name because the hardware has 8-16 legs that span out from the center. The spider's design helps distribute the load evenly in the test stand. The pieces are:

• Core stage simulator — a duplicate of the top of the SLS core stage that is approximately 10 feet tall and 27.5 feet in diameter. It was designed and built at Marshall.

• Launch vehicle stage adapter (LVSA) — connects the SLS core stage and the interim cryogenic propulsion stage (ICPS). The ICPS is a liquid oxygen/liquid hydrogen-based system that will give Orion the big, in-space push needed to fly beyond the moon before it returns to Earth on the first flight of SLS in 2018. The LVSA test hardware is 26.5 feet tall, with a bottom diameter of 27.5 feet and a top diameter of 16.8 feet. It was designed and built by prime contractor Teledyne Brown Engineering of Huntsville.

• Frangible joint assembly — part of the separation system on the SLS. The flight version will have small explosive devices installed that will separate the ICPS from the rest of the rocket in space. Only the structural part of the frangible joint assembly is included for this test series. It was designed and built by The Boeing Co. in Huntsville and United Launch Alliance of Decatur.

• ICPS — The qualification test article, without the engine, is around 29 feet tall and 16.8 feet in diameter. It will be filled with liquid nitrogen for testing, rather than liquid oxygen and liquid hydrogen. "Liquid nitrogen is the safest cryogenic media to use for testing," VanCleave said. The ICPS was designed and built by Boeing and United Launch Alliance.

• Orion stage adapter – connects the Orion to the ICPS. It is 4.8 feet tall, with a 16.8-foot bottom diameter and 18-foot top diameter. It was designed and built at Marshall. The adapter technology was used for Orion's first test flight in December 2014.

• Orion spacecraft simulator – a replica of the bottom portion of the exploration vehicle that will carry the crew to space, provide emergency abort capability, sustain the crew during the space travel, and provide safe re-entry from deep space return velocities. The simulator also was designed and built at Marshall, and is 4.5 feet tall and 18 feet in diameter.

The qualification articles are almost exact to flight hardware specifications. The core stage simulator was loaded into the test stand Sept. 21, with the LVSA following on Oct. 12. The other three qualification articles and the Orion simulator will complete the stack later this fall. Testing is scheduled to begin in early 2017.

Ready, Set, Test

Approximately 50 test cases are planned for the series. The qualification test articles will be outfitted with 28 mechanical load lines, which will use hydraulic pressure to push and pull on the test articles. The ICPS tanks also will be filled with liquid nitrogen, which will subject the hardware to pressure as high as 56 pounds per square inch — relative to atmospheric pressure. More than 170,000 pounds of liquid nitrogen will be used in the tanks for most of the load cases, and 500,000 pounds of axial hydraulic force will be applied to the entire test stack. Engineers will not test to failure for this series.

Data from the tests will be recorded through 1,900 instrumentation channels, measuring the strain on the test articles, temperature, deflection and other factors. The test data will be compared to computer models to verify the integrity of the hardware and ensure it can withstand the forces it will experience during flight. This also will be a type of practice run for assembly operations before the rocket hardware is stacked in the Vehicle Assembly Building at Kennedy Space Center in Florida ahead of launch.

The initial SLS configuration will have a minimum 70-metric-ton (77-ton) lift capability and be powered by twin solid rocket boosters and four RS-25 engines. The next planned upgrade of SLS will use a powerful exploration upper stage for more ambitious missions with a 105-metric-ton (115-ton) lift capacity. A third configuration will add a pair of advanced solid or liquid propellant boosters to provide a 130-metric-ton (143-ton) lift capacity. In each configuration, SLS will continue to use the same core stage and four RS-25 engines.

posted 11-15-2016 11:56 AM               

Hardware for NASA's Journey to Mars is 'Big Catch' for Upcoming Test Series

A key piece of hardware for NASA's new rocket, the Space Launch System, completed a five-hour journey by barge June 19 along the Tennessee River in North Alabama. Fishermen may have caught a glimpse of it on its way from United Launch Alliance in Decatur, Alabama, to the agency's Marshall Space Flight Center in Huntsville, Alabama. SLS will be the most powerful rocket in the world and enable human missions to deep space, including the journey to Mars.

Above: Two cranes lift the interim cryogenic propulsion stage test article, built and delivered by United Launch Alliance in Decatur to NASA's Marshall Space Flight Center in Huntsville, Alabama. Credit: NASA/MSFC/Emmett Given

The transported hardware is a prototype of the interim cryogenic propulsion stage (ICPS), and will be a "big catch" for testing later this year. On the first flight of SLS with NASA's deep-space craft, the ICPS is the liquid oxygen/liquid hydrogen-based system that will give Orion the big, in-space push needed to fly beyond the moon before it returns to Earth.

The test version ICPS joins other structural test articles and simulators that make up the upper portion of the rocket. When all the hardware is completed, engineers will stack them together and move the 56-foot-tall structure to a test stand at Marshall.

"The delivery of this test hardware is critical to preparing for a big test series later this year," said Chris Calfee, ICPS project manager at Marshall, where the SLS Program is managed for NASA. "For that test series, we will subject the hardware to forces similar to those experienced in flight. This will ensure the hardware can handle the forces without compromising the structural integrity of each piece."

In addition to the ICPS, structural test articles have been completed for the:

• Orion spacecraft simulator – a replica of the bottom portion of the exploration vehicle that will carry the crew to space, provide emergency abort capability, sustain the crew during the space travel, and provide safe re-entry from deep space return velocities.

• Orion stage adapter — connects the Orion to the ICPS. The adapter technology was used for Orion's first test flight in December 2014.

• Core stage simulator — a duplicate of the top of the SLS core stage that is approximately 10 feet tall and 27 feet in diameter. The rocket's entire core stage will tower more than 200 feet tall and house the vehicle's avionics and software, and the flight computer. It also will store cryogenic liquid hydrogen and liquid oxygen that will feed the vehicle's RS-25 engines.

Above: Space Launch System Program Manager John Honeycutt thanks United Launch Alliance (ULA) and Boeing Co. employees for their work on the completed interim cryogenic propulsion stage (ICPS) test article during a media event Oct. 26 at ULA's facility in Decatur, Alabama. Credit: ULA

A structural test article for the launch vehicle stage adapter (LVSA), which connects the core stage and the upper stage, has completed welding and is now being outfitted with hundreds of sensors to collect test data. Engineers also are continuing work on the logistics behind such a large test operation, including building handling equipment that will transport the hardware to the test stand. "Testing is probably the most important part of building a rocket," said Steve Creech, acting director of the Spacecraft and Payload Integration and Evolution Office at Marshall. "We look forward to the test series coming up, and continuing work on flight hardware that is currently in production for the ICPS, Orion stage adapter and LVSA."

For the ICPS, Boeing modified the design of the existing ULA Delta Cryogenic Second Stage, used on United Launch Alliance's Delta IV family of launch vehicles. It will be powered by an Aerojet Rocketdyne RL-10B engine – also currently used on the Delta Cryogenic Second Stage. Modifications to the Delta Cryogenic Second Stage include lengthening the liquid hydrogen tank, adding hydrazine bottles for attitude control and making some minor avionics changes to meet the design parameters and performance characteristics as needed by NASA to meet the flight objectives.

The Boeing/ULA team is working to complete production of the ICPS flight hardware that will launch on the first SLS flight with Orion in late 2018. "We are making great progress on the flight hardware with our ULA and NASA partners," said Cataldo Mazzola, the Boeing ICPS test manager.

posted 11-17-2016 06:11 PM               

NASA SLS Propulsion System Goes into Marshall Stand Ahead of Big Test Series

NASA engineers installed a test version of a crucial piece of hardware for the Space Launch System rocket in a 65-foot-tall test stand Nov. 17 at the agency's Marshall Space Flight Center in Huntsville, Alabama. SLS will be the most powerful rocket ever built for human missions to deep space with the Orion spacecraft, including the Journey to Mars.

Above: A test version of the interim cryogenic propulsion stage (ICPS) for NASA's Space Launch System rocket is loaded into the test stand at the agency's Marshall Space Flight Center in Huntsville, Alabama. Credit: NASA/MSFC/Brian C. Massey

The hardware is a test version of the interim cryogenic propulsion stage (ICPS), which is a liquid oxygen/liquid hydrogen-based system that will give Orion the in-space push needed to fly beyond the moon before it returns to Earth on the first flight of SLS and Orion in late 2018. The ICPS will be stacked with three other test articles and two simulators that make up the upper portion of the SLS rocket ahead of a rigorous test series in early 2017.

"The installation of the ICPS is another big step in getting ready for the test series, which will ensure that the hardware can endure the incredible stresses of launch," said Steve Creech, deputy manager of the Spacecraft and Payload Integration & Evolution Office at Marshall, which manages the SLS Program for the agency. "In addition to testing, work is underway on flight pieces of the upper part of the rocket, including the ICPS. NASA and our prime contractor teams are working diligently toward mission success for first flight, and this test series also will provide crucial data to support future missions, including the journey to Mars."

The ICPS test article, without the engine, is around 29 feet tall and 16.8 feet in diameter. It is the largest piece of hardware for the test series, and was designed and built by The Boeing Co. in Huntsville and United Launch Alliance of Decatur.

Above: The ICPS is the liquid oxygen/liquid hydrogen-based propulsion stage that will give NASA's Orion spacecraft the in-space push needed to fly beyond the moon before it returns to Earth on the first flight of SLS and Orion in 2018. Credit: NASA/MSFC/Brian C. Massey

The hardware — some being almost exact to flight specifications — will be pushed, pulled and twisted during the tests. The ICPS joins two other pieces of hardware already installed in the stand. The core stage simulator was loaded into the test stand Sept. 21, with the launch vehicle stage adapter (LVSA) following on Oct. 12. The core stage simulator is a duplicate of the top of the SLS core stage that is approximately 10 feet tall and 27.5 feet in diameter. It was designed and built at Marshall.

The LVSA connects the SLS core stage and the ICPS. The LVSA test hardware is 26.5 feet tall, with a bottom diameter of 27.5 feet and a top diameter of 16.8 feet. It was designed and built by prime contractor Teledyne Brown Engineering of Huntsville. The other three qualification articles and the Orion simulator will complete the stack later this fall. Approximately 50 test cases are planned for the upcoming series.

The initial SLS configuration will have a minimum 70-metric-ton (77-ton) lift capability and be powered by twin solid rocket boosters and four RS-25 engines. The next planned upgrade of SLS will use a more powerful exploration upper stage for more ambitious missions with a 105-metric-ton (115-ton) lift capacity.

posted 02-03-2018 08:20 PM               

Structural Testing Complete on SLS Core Stage Powerhouse

After numerous tests using millions of pounds of force, engineers have successfully completed structural qualification testing on the engine section for NASA's new deep-space rocket, the Space Launch System.

A true powerhouse, with four RS-25 engines and side attachment points for two solid rocket boosters, the engine section is located at the bottom of the rocket's massive core stage. The 212-foot-tall core stage will be the backbone of all SLS configurations, making the tests critically important for upcoming missions sending crews to the Moon, Mars and beyond.

During launch, the engines and boosters will produce more than 8 million pounds of thrust, requiring the engine section to be incredibly strong.

"These tests mark significant progress to the pad for the first flight of SLS," said Mark White, lead test engineer for the engine section at NASA's Marshall Space Flight Center in Huntsville, Alabama. "The tests performed by NASA with core stage prime contractor Boeing prove the hardware is strong enough to withstand the stresses and loads of launch and ascent."

The engine section structural test article was built at NASA's Michoud Assembly Facility in New Orleans, and shipped to Marshall for testing. At Marshall, the hardware was installed into a unique 50-foot test stand where electronically controlled hydraulic cylinders pushed, pulled and bent the test article with millions of pounds of force.

"SLS will be the most powerful rocket in the world and to simulate the incredible loads it will produce, NASA and Boeing had to be innovative when designing the stand," said White. "A traditional test stand, reacting onto the concrete, would have filled the entire test bay, leaving no room to maneuver and install the hardware."

Traditional structural test stands are bolted to deep concrete foundations to absorb the force from the test back the ground. The Marshall test stand -- which looks much like a bird cage built around the test article -- is completely self-reacting, meaning the test stand itself is designed to be both strong enough and flexible enough to withstand the energy of the test. It sits on only four concrete pads, each roughly the size of a pizza box, allowing the stand to be more compact and flexible.

Inside the 1.7 million-pound test stand, the engine section test article hangs with a cryogenic supply system simulating the frigid temperatures created by the rocket's liquid hydrogen tank. Using more than 16,000 fasteners, the test article is connected to the stand and the more than 50 actuators used to simulate the expected flight loads.

During tests, the actuators simulated more than 3 million pounds of upward RS-25 engine thrust loads and up to 750,000 pounds of loads on each side for the outward forces created by the solid rocket boosters. A series of tests also validated brackets designed to hold feedlines from the liquid oxygen tank.

Located near the top of the rocket's core stage, the liquid oxygen tank will supply the oxidizer needed to power the four RS-25 engines. The liquid oxygen will travel more than 150 feet to the engines down the outside of the core stage, past the intertank and liquid hydrogen tank, via a large feedline known as the "downcomer." The tests verified that the engine section feedline brackets would perform as expected when the heavy liquid makes the turn toward the engines in flight.

Engineers recorded and analyzed over 3,000 channels of data for each test case to verify the capabilities of the engine section and downcomer. Teams compared the data to design and analysis models to validate the accuracy of the predicted loads.

"The core stage structural qualification test campaign is NASA's largest such effort since the Space Shuttle Program," said Heather Haney, SLS core stage dry structures test lead at Marshall. "Next, we'll test the intertank and then the rocket's two colossal fuel tanks. It's an exciting time for the future of deep-space exploration, and these tests move SLS closer to its first launch."

SLS, which is managed at Marshall, will enable a new era of exploration beyond Earth's orbit, launching astronauts in NASA's Orion spacecraft on deep-space exploration missions to the Moon and eventually to Mars. On the first flight of SLS, Exploration Mission-1, the rocket will send an uncrewed Orion thousands of miles beyond the Moon before the spacecraft returns to Earth.

Major welding on all five parts of the core stage, including the engine section, for the first flight has been completed and the components are being outfitted for flight. The four RS-25 engines and engine controllers for the first mission have been certified and are ready to be joined to the engine section.

posted 01-15-2019 02:25 PM               

SLS Liquid Hydrogen Tank Test Article Loaded into Test Stand

The largest piece of structural test hardware for America’s new deep space rocket, the Space Launch System, was loaded into Test Stand 4693 at NASA’s Marshall Space Flight Center in Huntsville, Alabama Jan. 14, 2019.

The liquid hydrogen tank is part of the rocket’s core stage that is more than 200 feet tall with a diameter of 27.6 feet, and stores cryogenic liquid hydrogen and liquid oxygen that will feed the vehicle’s RS-25 engines. The liquid hydrogen tank test article is structurally identical to the flight version of the tank that will comprise two-thirds of the core stage and hold 537,000 gallons of supercooled liquid hydrogen at minus 423 degrees Fahrenheit.

Dozens of hydraulic cylinders in the 215-foot-tall test stand will push and pull the tank, subjecting it to the same stresses and loads it will endure during liftoff and flight.

posted 12-06-2019 08:50 PM               

NASA Engineers Break SLS Test Tank on Purpose to Test Extreme Limits

Engineers at NASA's Marshall Space Flight Center in Huntsville, Alabama, on Dec. 5 deliberately pushed the world's largest rocket fuel tank beyond its design limits to really understand its breaking point. The test version of the Space Launch System rocket's liquid hydrogen tank withstood more than 260% of expected flight loads over five hours before engineers detected a buckling point, which then ruptured. Engineers concluded the test at approximately 11 p.m.

Above: The Dec. 5 test pushed the tank to its limits to see how much force it would take to cause the tank’s structure to fail. This image shows the resulted buckling of the structure when the tank failed after exposure to more than 260% of expected flight loads over 5 hours. (NASA/Dennis Olive)

"We purposely took this tank to its extreme limits and broke it because pushing systems to the point of failure gives us additional data to help us build rockets intelligently," said Neil Otte, chief engineer of the SLS Stages Office at Marshall. "We will be flying the Space Launch System for decades to come, and breaking the propellant tank today will help us safely and efficiently evolve the SLS rocket as our desired missions evolve."

The test version of the tank aced earlier tests, withstanding forces expected at engine thrust levels planned for Artemis lunar missions, showing no signs of cracks, buckling or breaking. The test on Dec. 5 — conducted using a combination of gaseous nitrogen for pressurization and hydraulics for loads — pushed the tank to the limits by exposing it to higher forces that caused it to break as engineers predicted. Earlier tests at Marshall certified the tank for both the current version of the SLS — called Block 1, which will use an upper stage called the Interim Cryogenic Propulsion Stage — and the Block 1B version that will replace the ICPS with the more powerful Exploration Upper Stage.

"This final tank test marks the largest-ever controlled test-to-failure of a NASA rocket stage pressurized tank," said Mike Nichols, Marshall's lead test engineer for the tank. This data will benefit all aerospace companies designing rocket tanks."

For all the tests, NASA and Boeing engineers simulated liftoff and flight stresses on a test version of the Space Launch System liquid hydrogen tank that is structurally identical to the flight tank. Throughout the tests in Marshall's 215-foot-tall test stand, they used large hydraulic pistons to deliver millions of pounds of punishing compression, tension and bending forces on the robust test tank.

The test tank was fitted with thousands of sensors to measure stress, pressure and temperature, while high-speed cameras and microphones captured every moment to identify buckling or cracking in the cylindrical tank wall.

"The initial tank buckling failure occurred at the same relative location as predicted by the Boeing analysis team and initiated within 3% of the predicted failure load," said Luke Denney, qualification test manager for Boeing's Test & Evaluation Group. "The accuracy of these predictions against real life testing validates our structural models and provides high confidence in the tank design."

Teams at Michoud are wrapping up functional testing of the assembled SLS core stage for the Artemis I mission and already are building the core stage for the Artemis II mission. The 212-foot-tall core stage is the largest, most complex rocket stage NASA has built since the Saturn V stages that powered the Apollo missions to the Moon.

"We are happy that NASA's tests with the core stage structural test article will contribute not only to Space Launch System flights but also to the design of future rocket propellant tanks," said Julie Bassler, manager of the SLS Stages Office.

posted 06-22-2020 11:10 AM               

NASA Prepares to Complete Artemis SLS Rocket Structural Testing

NASA's Space Launch System (SLS) Program is concluding its structural qualification test series with one upcoming final test that will push the design for the rocket's liquid oxygen tank to its limits at NASA's Marshall Space Flight Center in Huntsville, Alabama.

Above: The liquid oxygen tank structural test article, shown here, for NASA’s Space Launch System (SLS) rocket’s core stage was the last test article loaded into the test stand July 10, 2019. (NASA/Tyler Martin)

In the name of science, engineers will try to break a structural test article of the tank — on purpose. The liquid oxygen tank's structure is identical to the tank that is part of the SLS core stage, which will provide power to help launch the Artemis missions to the Moon. The tank is enclosed in a cage-like structure that is part of the test stand. Hydraulic systems will apply millions of pounds of force to push, pull and bend the liquid oxygen tank test article to see just how much pressure the tank can take. The forces simulate what the tank is expected to experience during launch and flight. For the test, the tank will be filled with water to simulate the liquid oxygen propellant used for flight, and when the tank ruptures, the water may create a loud sound as it bursts through the tank's skin.

"We take rocket tanks to extreme limits and break them because pushing systems to the point of failure gives us a data to help us build rockets more intelligently," said Neil Otte, chief engineer for the SLS Stages Office at Marshall. "Breaking the propellant tank today on Earth will provide us with valuable data for safely and efficiently flying SLS on the Artemis missions to the Moon."

Earlier this year, NASA and Boeing engineers subjected the tank to 23 baseline tests that simulate actual flight conditions, and the tank aced the tests. The tank is fitted with thousands of sensors to measure stress, pressure and temperature, while high-speed cameras and microphones capture every moment to identify buckling or cracking in the cylindrical tank wall. This final test will apply controlled forces stronger than those engineers expect the tank to endure during flight, similar to the test that ruptured the liquid hydrogen tank and created noise heard in some Huntsville neighborhoods near Marshall.

This is final test in a series of structural qualification tests that have pushed the rocket's structures to the limits from top to bottom to help ensure the rocket is ready for the Artemis lunar missions. Completion of this upcoming test will mark a major milestone for the SLS Program.

The Marshall team started structural qualification testing on the rocket in May 2017 with an integrated test of the upper part of the rocket stacked together: the Interim Cryogenic Propulsion Stage, the Orion stage adapter and the launch vehicle stage adapter. Then the team moved on to testing the four largest structures that make up the 212-foot-tall core stage. The last baseline test for Artemis I was completed in March 2020 before the team's access to Marshall was restricted because of the COVID-19 pandemic. The NASA and Boeing team returned to work the first week in June to prepare for conducting the final liquid oxygen test to failure.

The structural qualification tests help verify models showing the structural design can survive flight. Structural testing has been completed on three of the largest core stage structures: the engine section, the intertank, and the liquid hydrogen tank. The liquid oxygen tank has completed baseline testing and will now wrap up core stage testing with the upcoming test to find the tank's point of failure.

"The liquid oxygen tests and the other tests to find the point of failure really put the hardware through the paces," said April Potter, the SLS test project manager for liquid oxygen and liquid hydrogen structural tests. "NASA will now have the information to build upon our systems and push exploration farther than ever before."

posted 06-26-2020 01:03 PM               

NASA Completes Artemis Space Launch System Structural Testing Campaign

On June 24, 2020, engineers completed the Space Launch System (SLS) rocket's structural testing campaign for the Artemis lunar missions by testing the liquid oxygen structural test article to find its point of failure.

"The Space Launch System and Marshall test team have done a tremendous job of accomplishing this test program, marking a major milestone not only for the SLS Program but also for the Artemis program," said John Honeycutt, the SLS Program Manager. "From building the test stands, support equipment and test articles to conducting the tests and analyzing the data, it is remarkable work that will help send astronauts to the Moon."

For the final test, the liquid oxygen tank test article — measuring 70 feet tall and 28 feet in diameter — was bolted into a massive 185,000-pound steel ring at the base of Marshall's Test Stand 4697. Hydraulic cylinders were then calibrated and positioned all along the tank to apply millions of pounds of crippling force from all sides while engineers measured and recorded the effects of the launch and flight forces. The liquid oxygen tank circumferentially failed in the weld location as engineers predicted and at the approximate load levels expected, proving flight readiness and providing critical data for the tank's designers. The test concluded at approximately 9 p.m. CT. This final test on the liquid oxygen structural test article met all the program milestones.

The successful completion of SLS structural qualification testing at NASA's Marshall Space Flight Center in Huntsville, Alabama wraps up the largest test campaign at the center since tests conducted for the Space Shuttle Program, more than 30 years ago. During the test campaign five structural test articles underwent 199 separate test cases and more than 421 gigabytes of data were collected to add to computer models used to design the rocket. The final test marks the achievement of all SLS structural testing requirements prior to the Artemis I mission — the first in a series of increasingly complex missions that will enable human exploration to the Moon and Mars.

Above: Engineers completed almost 200 tests on the Space Launch System (SLS) rocket by breaking the liquid oxygen tank test article. This test was the last in a 3-year structural campaign to ensure the rocket's structure was designed to endure the rigors of spacefllight. (NASA/David Olive)

Earlier this year, NASA and engineers from Boeing, the core stage prime contractor, completed 24 baseline tests that simulated actual flight conditions on the liquid oxygen structural test article. For all the tests, thousands of sensors measure stress, pressure and temperature while high-speed cameras and microphones sought to identify any buckling or cracking in the tank's cylindrical wall. The data gathered from this baseline test helped qualify the SLS core stage structures and integrated upper stage for flight.

The Marshall team has been conducting structural qualification testing on the rocket since May 2017 with an integrated test of the upper part of the rocket stacked together — including the interim cryogenic propulsion stage, the Orion stage adapter and the launch vehicle stage adapter. That was followed by testing of the four largest structures that compose the core stage — the engine section, the intertank, the liquid hydrogen tank and the liquid oxygen tank. Each of these tests provided additional data to computer models that predict how the structures will perform under the harsh conditions of launch and flight.

"The Marshall test lab team has worked closely with the Space Launch System Program to test the rocket's structures from the top to bottom," said Ralph Carruth, Marshall's test lab director. "After watching the test stands being built, working alongside SLS and Boeing engineers to establish testing procedures and conducting and gathering results of five structural qualifying tests, we are proud to contribute data shows these structures can withstand the rigors of flight."

With the conclusion of testing, designers now have data that may be helpful in optimizing SLS hardware. SLS will have the power to send astronauts forward to the Moon and ultimately to Mars. Testing the new, complex pieces of hardware is critical to the success not only of the first flight test of SLS and NASA's Orion spacecraft, but also to all future missions.

"This year is a landmark year for core stage testing for the Artemis missions," said Julie Bassler, the SLS stages manager. "We have successfully completed our core stage major structural tests at Marshall Space Flight Center and are making progress on Green Run testing of the Artemis I core stage at Stennis Space Center that will simulate launch. All these tests are not only valuable for the first Artemis mission but also validates the new integrated design of the SLS core stage structure, propulsion and avionics systems and ensures its readiness for future flights."