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  [SLS] RS-25 (SSME) engine tests (Stennis A-1)

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Author Topic:   [SLS] RS-25 (SSME) engine tests (Stennis A-1)
Robert Pearlman
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posted 01-12-2012 06:02 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
NASA release
Shuttle engines move from Kennedy to Stennis

The relocation of the RS-25D space shuttle main engine inventory from Kennedy Space Center's Engine Shop in Cape Canaveral, Fla., is underway. The RS-25D flight engines, repurposed for NASA's Space Launch System, are being moved to NASA's Stennis Space Center in south Mississippi.

The Space Launch System (SLS) is a new heavy-lift launch vehicle that will expand human presence beyond low-Earth orbit and enable new missions of exploration across the solar system. The Marshall Space Flight Center in Huntsville, Ala., is leading the design and development of the SLS for NASA, including the engine testing program.

SLS will carry the Orion spacecraft, its crew, cargo, equipment and science experiments to destinations in deep space.


Credit: NASA/Gianni Woods

Above: In the Space Shuttle Main Engine Processing Facility at NASA's Kennedy Space Center in Florida, a transportation canister rolls toward a Pratt Whitney Rocketdyne space shuttle main engine (SSME).

"The relocation of RS-25D engine assets represents a significant cost savings to the SLS Program by consolidating SLS engine assembly and test operations at a single facility," said William Gerstenmaier, NASA’s Associate Administrator for Human Exploration and Operations Mission Directorate.

The RS-25Ds – to be used for the SLS core stage – will be stored at Stennis until testing begins at a future date. Testing is already under way on the J-2X engine, which is planned for use in the SLS upper stage. Using the same fuel system – liquid hydrogen and liquid oxygen – for both core and upper stages reduces costs by leveraging the existing knowledge base, skills, infrastructure and personnel.

"This enables the sharing of personnel, resources and practices across all engine projects, allows flexibility and responsiveness to the SLS program, and it is more affordable," said Johnny Heflin, RS-25D core stage engine lead in the SLS Liquid Engines Office at Marshall. "It also frees up the space, allowing Kennedy to move forward relative to commercial customers."

The 15 RS-25D engines at Kennedy are being transported on the 700-mile journey using existing transportation and processing procedures that were used to move engines between Kennedy and Stennis during the Space Shuttle Program. They will be relocated one at a time by truck.

Built by Pratt & Whitney Rocketdyne of Canoga Park, Calif. the RS-25D engine powered NASA’s space shuttle program with 100 percent mission success.

See here for discussion of RS-25 engine use for the Space Launch System.

Robert Pearlman
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posted 06-09-2013 10:03 AM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
NASA Marshall Space Flight Center (MSFC) release
Production of Key Equipment Paves Way for NASA SLS RS-25 Testing

NASA plans to begin testing RS-25 engines for its new Space Launch System (SLS) in the fall of 2014, and the agency's Stennis Space Center in Mississippi has a very big — literally — item to complete on the preparation checklist.

Fabrication recently began at Stennis on a new 7,755-pound thrust frame adapter for the A-1 Test Stand to enable testing of the engines that will provide core-stage power for NASA's SLS. The stand component is scheduled to be completed and installed by November 2013.

Above: Design image shows a RS-25 rocket engine installed on the A-1 Test Stand at NASA's Stennis Space Center.

"We initially thought we would have to go offsite to have the equipment built," said Gary Benton, RS-25 test project manager at Stennis. "However, the Stennis design team figured out a way to build it here with resulting cost and schedule savings. It's a big project and a critical one to ensure we obtain accurate data during engine testing."

Each rocket engine type requires a thrust frame adapter unique to its specifications. On the test stand, the adapter is attached to the thrust measurement system. A rocket engine then is attached to the adapter, which must hold the engine in place and absorb the thrust produced during a test, while allowing accurate measurement of the engine performance.

The J-2X equipment installed on the A-1 Test Stand now cannot be used to test RS-25 engines since it does not match the engine specifications and thrust requirements. For instance, the J-2X engine is capable of producing 294,000 pounds of thrust. The RS-25 engine will produce approximately 530,000 pounds of thrust.

Above: Fabrication is under way on a 7,755-pound thrust frame adapter to be installed on the A-1 Test Stand at NASA's Stennis Space Center in south Mississippi.

NASA and the Lockheed Martin Test Operations Contract Group team worked together in designing the new adapter to make sure such requirements were met. They also communicated closely with the Jacobs Technology welding and machine shop teams to make sure what was being designed actually could be built.

The design had to account for a number of considerations, such as specific stresses on the equipment as an engine is fired and then gimbaled (rotated) during a test; what type and strength of bolts are needed to fully secure the equipment; and what materials can be used to build the adapter.

"This is a very specific process," Benton said. "It is critical that thrust data not be skewed or compromised during a test, so the adapter has to be precisely designed and constructed."

The fabrication process itself involves handling and shaping large segments of certain material, which required welders to receive specialized training. In addition, shop personnel had to create a welding procedure for dealing with the chosen construction material. For instance, the area of material being welded must maintain a heat of 300 degrees in order to ensure welds bond properly. That procedure and other specifications are being incorporated into Stennis standards.

"It's a challenging project," said Kent Morris, RS-25 project manager for Jacobs Technology. "It's similar to the J-2X adapter project, but larger. It will take considerable man hours to perform the welding and machining needed on the material. The material used for the engine mounting block alone is 32 inches in diameter and 20 inches thick."

Physically, the adapter is the largest facility item on the preparation checklist for RS-25 testing, but it is far from the only one, Benton said. Additional modifications will be made to the test stand configuration and equipment once J-2X gimbal testing is complete this summer.

Once testing begins, engineers and test team personnel at Stennis will draw on a wealth of engine testing experience. The RS-25 engines, previously known as the space shuttle main engines were tested at Stennis for more than three decades.

Robert Pearlman
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From: Houston, TX
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posted 04-11-2014 04:01 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
NASA release
NASA gears up for next set of engine tests for Space Launch System

The RS-25 engine that will power NASA's new rocket, the Space Launch System (SLS), off the launch pad and on journeys to an asteroid and Mars is getting ready for the test stand. And it is packing a big punch.

Engineers at NASA's Stennis Space Center near Bay St. Louis, Miss., are now focusing their attention on preparing the RS-25 engine after completing testing of the J-2X engine April 10. Four RS-25 engines, previously known as space shuttle main engines, will muscle the core stage of SLS for each of its missions. Towering more than 200 feet tall with a diameter of 27.6 feet, the core stage will store cryogenic liquid hydrogen and liquid oxygen that will feed the vehicle’s RS-25s.

Modifications to the engines, like higher thrust levels, were needed on the proven workhorse to prepare them for the SLS. To accommodate a higher thrust level, the number of engines was increased from three, used during the shuttle era, to four. The power level also was increased for each engine.

Engines on the shuttle ran at 491,000 pounds vacuum thrust (104.5-percent of rated power level). After analyzing temperature and other factors on the engine, the power level was increased for SLS to 512,000 pounds vacuum thrust (109 percent of rated power level).

Modifications also have been made to the A-1 test stand at Stennis to prepare for the RS-25's first hot-fire test.

Robert Pearlman
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posted 07-17-2014 12:30 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
NASA release
NASA Begins Engine Test Project for Space Launch System Rocket

Engineers have taken a crucial step in preparing to test parts of NASA's Space Launch System (SLS) rocket that will send humans to new destinations in the solar system. They installed on Thursday an RS-25 engine on the A-1 Test Stand at the agency's Stennis Space Center near Bay St. Louis, Mississippi.

The Stennis team will perform developmental and flight certification testing of the RS-25 engine, a modified version of the space shuttle main engine that powered missions into space from 1981 to 2011. The SLS's core stage will be powered by a configuration of four RS-25 engines, like the one recently installed on the A-1 stand.

"This test series is a major milestone because it will be our first opportunity to operate the engine with a new controller and to test propellant inlet conditions for SLS that are different than the space shuttle," said Steve Wofford, SLS Liquid Engines Element manager. "This testing will confirm the RS-25 will be successful at powering SLS."

Early tests on the engine will collect data on the performance of its new advanced engine controller and other modifications. The controller regulates valves that direct the flow of propellant to the engine, which determines the amount of thrust generated during an engine test, known as a hotfire test. In flight, propellant flow and engine thrust determine the speed and trajectory of a spacecraft. The controller also regulates the engine startup sequence, which is especially important on an engine as sophisticated as the RS-25. Likewise, the controller determines the engine shutdown sequence, ensuring it will proceed properly under both normal and emergency conditions.

"Installation of RS-25 engine No. 0525 signals the launch of another major rocket engine test project for human space exploration on the A-1 Test Stand," said Gary Benton, RS-25 rocket engine test project manager at Stennis.

The SLS is designed to carry astronauts in NASA's Orion spacecraft deeper into space than ever before, to destinations including an asteroid and Mars. NASA is using existing and in-development hardware and infrastructure, including the RS-25 engine, to the maximum extent possible to enable NASA to begin deep space missions sooner.

Testing of engine No. 0525 begins in the coming weeks on a test stand originally built in the 1960s for Apollo-era engines that helped launch the lunar missions. The stand has since been used for several major testing projects, and NASA spent almost a year modifying the structure to accommodate the RS-25 engine.

Robert Pearlman
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posted 01-09-2015 07:42 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
NASA release
RS-25 Engine Testing Blazes Forward for NASA's Space Launch System

The new year is off to a hot start for NASA's Space Launch System (SLS). The engine that will drive America's next great rocket to deep space blazed through its first successful test Jan. 9 at the agency's Stennis Space Center near Bay St. Louis, Mississippi.

Above: The RS-25 engine fires up for a 500-second test Jan. 9 at NASA's Stennis Space Center near Bay St. Louis, Mississippi.

The RS-25, formerly the space shuttle main engine, fired up for 500 seconds on the A-1 test stand at Stennis, providing NASA engineers critical data on the engine controller unit and inlet pressure conditions. This is the first hot fire of an RS-25 engine since the end of space shuttle main engine testing in 2009. Four RS-25 engines will power SLS on future missions, including to an asteroid and Mars.

"We've made modifications to the RS-25 to meet SLS specifications and will analyze and test a variety of conditions during the hot fire series," said Steve Wofford, manager of the SLS Liquid Engines Office at NASA's Marshall Space Flight Center in Huntsville, Alabama, where the SLS Program is managed. "The engines for SLS will encounter colder liquid oxygen temperatures than shuttle; greater inlet pressure due to the taller core stage liquid oxygen tank and higher vehicle acceleration; and more nozzle heating due to the four-engine configuration and their position in-plane with the SLS booster exhaust nozzles."

Above: This is the first of eight tests for the development engine, which will provide NASA engineers with critical data on the engine controller unit and inlet pressure conditions.

The engine controller unit, the "brain" of the engine, allows communication between the vehicle and the engine, relaying commands to the engine and transmitting data back to the vehicle. The controller also provides closed-loop management of the engine by regulating the thrust and fuel mixture ratio while monitoring the engine's health and status. The new controller will use updated hardware and software configured to operate with the new SLS avionics architecture.

"This first hot-fire test of the RS-25 engine represents a significant effort on behalf of Stennis Space Center's A-1 test team," said Ronald Rigney, RS-25 project manager at Stennis. "Our technicians and engineers have been working diligently to design, modify and activate an extremely complex and capable facility in support of RS-25 engine testing."

Testing will resume in April after upgrades are completed on the high pressure industrial water system, which provides cool water for the test facility during a hot fire test. Eight tests, totaling 3,500 seconds, are planned for the current development engine. Another development engine later will undergo 10 tests, totaling 4,500 seconds. The second test series includes the first test of new flight controllers, known as green running.

Above: A close-up view from the test stand.

The first flight test of the SLS will feature a configuration for a 70-metric-ton (77-ton) lift capacity and carry an uncrewed Orion spacecraft beyond low-Earth orbit to test the performance of the integrated system. As the SLS is upgraded, it will provide an unprecedented lift capability of 130 metric tons (143 tons) to enable missions even farther into our solar system.

Robert Pearlman
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posted 05-28-2015 02:21 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
NASA release
Some Assembly Required: The Newest RS-25 Joins the Space Launch System Family

NASA's Space Launch System, America's new deep space exploration rocket, has a new addition to the family with the completed assembly of RS-25 Engine 2063. The RS-25 engine will power the core stage of the SLS, the launch vehicle that will take humans and cargo on deep space missions, including to an asteroid and ultimately to Mars.

Engine maker Aerojet Rocketdyne completed assembly of RS-25 Engine 2063 at NASA's Stennis Space Center near Bay St. Louis, Mississippi, after approximately three months of work. The new engine becomes the 16th assembled RS-25 flight engine in inventory for SLS flights. It will be one of four RS-25s used to power Exploration Mission 2, the second SLS launch targeted for the 2021 time frame. Testing of these four engines will begin later this year as work accelerates on NASA's newest launch vehicle.

While SLS is designed for deep space exploration far beyond Earth. It's also designed to take advantage of the investments the nation has already made in space exploration, including the RS-25.

Fourteen of the 16 RS-25 engines in the SLS inventory are veterans of numerous space shuttle missions, where they were commonly referred to as Space Shuttle Main Engines, or SSME. Engine 2063 is one of two additional "rookie" engines without previous shuttle flight experience. Engine 2063 will undergo acceptance testing to verify it is acceptable for flight, checking out the completed system. It does include some previously flown hardware, including the four turbopumps which have flown on several shuttle missions.

"Assembly of this new engine is part of a very busy year for the RS-25 team," said Steve Wofford, manager of the SLS Liquid Engines Office at NASA's Marshall Space Flight Center, where the SLS Program is managed for the agency. "We're testing one engine, developing a new controller and planning to manufacture new engines in the future."

Engine 2063 joins a famous family with a proud tradition. The RS-25 is one of the most tested large rocket engine in history, with more than 3,000 starts and over a million seconds of total ground test and flight firing time over 135 missions.

Four RS-25 liquid propellant engines will power the SLS for the eight-minute climb to orbit with the help of two solid propellant boosters – both flight qualified components of the Space Shuttle Program and now essential to SLS's unmatched payload capability.

"Completion of this engine is a significant accomplishment, considering it's been nearly five years since the last RS-25 was assembled," said Jim Paulsen, vice president of Program Execution Advanced Space & Launch Programs Aerojet Rocketdyne. "It's been a great opportunity for the team's SSME veterans to get reacquainted with this engine. For new members of the team, it's been an invaluable introduction to this dependable engine."

Four previously-flown RS-25s will be attached to the first SLS core stage and test fired together as a stage before being approved for the first SLS launch planned for 2018.

The SLS team began test firing one of the development engines with a new controller earlier this year to make sure it can meet the different performance and environmental conditions required by the SLS. The entire flight engine inventory will be upgraded with new state-of-the-art engine controllers, insulation and other details.

"There is nothing in the world that compares to this engine," added Paulsen. "It is great that we are able to adapt this advanced engine for what will be the world's most powerful rocket to usher in a new space age."

After the first four flights, NASA will start using brand new RS-25 engines. These "next generation" engines will be more affordable by utilizing components made with the latest 21st century electronics, cost saving manufacturing techniques and more cost effective materials.

"The RS-25 is still one of the most advanced engines in the world," said Philip Benefield, himself an SSME veteran now part of the team adapting the RS-25 to SLS. "It's an interesting challenge to put together a new SLS engine team of shuttle veterans and new engineers, much like the RS-25 incorporates veteran shuttle engine hardware and new hardware to meet new requirements."

For one of those new engineers, working on the RS-25 is the high point of a life-long interest in space exploration.

"Ever since I was in the third grade when I fell in love with the space program, I have always had the desire to work on a project that would take people further into space than ever before," said Esteban Barajas, a mechanical design engineer at Aerojet Rocketdyne.

"Now, being able to bring the space shuttle main engines roaring back to life with the many talented engineers who originally designed and built them is an incredible opportunity. As a young engineer, the experience has truly been invaluable."

Robert Pearlman
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posted 05-29-2015 06:40 AM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
NASA photo release
Steamy Summer Begins for SLS with RS-25 Test

A billowing plume of steam signals a successful 450-second test of the RS-25 rocket engine May 28 at NASA's Stennis Space Center near Bay St. Louis, Mississippi.

The hotfire test was conducted on the historic A-1 Test Stand where Apollo Program rocket stages and Space Shuttle Program main engines also were tested. RS-25 engines tested on the stand will power the core stage of NASA's new rocket, the Space Launch System (SLS), which is being developed to carry humans deeper into space than ever before. The heavy-lift SLS will be more powerful than any current rocket and will be the centerpiece of the nation's next era of space exploration, carrying humans to an asteroid and eventually to Mars.

Four RS-25 engines will power the SLS vehicle at launch, firing simultaneously to generate more than 1.6 million pounds of thrust. RS-25 engines are modified Space Shuttle Main Engines, which powered 135 successful low-Earth orbit missions.

One of the objectives being evaluated in this test is the new engine controller, or "brain." The RS-25 is unique among many engines in that it automatically runs through its cycles and programs. The controller monitors the engine conditions and communicates the performance needs. The performance specifications, such as what percentage of thrust is needed and when, are programmed into the controller before the engines are fired.

For example, if the engine is required to cycle up to 90 percent thrust, the controller monitors the fuel mixture ratio and regulates the thrust accordingly. It is essential that the controller communicates clearly with the engine; the SLS will be bigger than previous rockets and fly unprecedented missions, and its engines will have to perform in new ways. Tests at Stennis will ensure the new controller and engine are in sync and can deliver the required performance to meet the SLS requirements.

NASA engineers conducted an initial RS-25 engine test on the A-1 stand Jan. 9. Testing then was put on hold for scheduled work on the Stennis facility high-pressure industrial water system that provides the tens of thousands of gallons of water needed to cool the stand during an engine test. RS-25 testing now is set to continue through the summer.

Robert Pearlman
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posted 06-11-2015 10:13 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
NASA release
We have Ignition: NASA Space Launch System RS-25 Engine Fires Up for Third Test in Series

Ladies and gentlemen, we've started our engine. An RS-25 engine fired up for 500 seconds June 11 at NASA's Stennis Space Center near Bay St. Louis, Mississippi.

Four RS-25 engines will power NASA's new rocket, the Space Launch System, at speeds of 17,500 mph -- 73 times faster than the top speeds of an Indianapolis 500 race car -- to send astronauts on future missions beyond Earth's orbit, including to an asteroid and ultimately to Mars.

This is the third firing of an RS-25 development engine on the A-1 test stand at Stennis. The first RS-25 test in this series was conducted Jan. 9, and the second was May 28. Four more tests are planned for the current development engine.

"While we are using proven space shuttle hardware with these engines, SLS will have different performance requirements," said Steve Wofford, manager of the SLS Liquid Engines Office at NASA's Marshall Space Flight Center in Huntsville, Alabama. The Marshall Center manages the SLS Program for the agency. "That's why we are testing them again. This is a whole new ballgame -- we need way more power for these engines to be able to go farther than ever before when it comes to human exploration. And we believe the modifications we've made to these engines can do just that."

The first flight test of the SLS -- designated as Exploration Mission 1 -- will feature a configuration for a 70-metric-ton (77-ton) lift capacity and carry an uncrewed Orion spacecraft beyond low-Earth orbit to test the performance of the integrated system.

"We have several objectives that will be accomplished during this test series, which will provide critical data on the new engine controller unit, materials and engine propellant inlet pressure conditions," Wofford added.

The new engine controller unit, the "brain" of the engine, allows communication between the vehicle and the engine, relaying commands to the engine and transmitting data back to the vehicle. The controller also provides closed-loop management of the engine by regulating the thrust and fuel mixture ratio while monitoring the engine's health and status. The controller will use updated hardware and software configured to operate with the new SLS vehicle avionics architecture.

The test series will show how the RS-25 engines will perform with colder liquid oxygen temperatures; greater inlet pressure due to the taller SLS core stage liquid oxygen tank and higher vehicle acceleration; and more nozzle heating due to the four-engine configuration and its position in-plane with the SLS booster exhaust nozzles. New ablative insulation and heaters also will be tested during the series. Aerojet Rocketdyne of Sacramento, California, is the prime contractor for the RS-25 engine work.

Robert Pearlman
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Registered: Nov 1999

posted 06-26-2015 07:48 AM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
NASA release
Longest SLS Engine Test Yet Heats Up Summer Sky

South Mississippi was hotter than usual on June 25 when the fire and heat produced by the longest test firing yet of a Space Launch System (SLS) RS-25 rocket engine at NASA's John C. Stennis Space Center combined with already climbing summer temperatures.

Engineers conducted a 650-second test of a RS-25 developmental engine as part of its preparation for a return to deep-space missions aboard the new Space Launch System rocket. NASA is designing the SLS to carry humans deeper into space than ever before, to such destinations as an asteroid and Mars. The core stage of the new vehicle will be powered by four RS-25 engines, former space shuttles main engines operated at slightly higher power levels to provide the additional thrust needed to power the SLS.

The main goal of the series is to test the engine under simulated temperature, pressure and other changes required by the SLS design. The series also supports the development of a new controller, or "brain," for the engine. The controller monitors the engine status and communicates the programmed performance needs.

The first test in the series was in January. Testing resumed in May after scheduled work was completed on the high-pressure industrial water system that provides the tens of thousands of gallons of water needed during an engine test. Thursday's test firing, the fourth in the series, expands on the performance objectives of the first two firings, allowing engineers to better understand the engine under a range of operating conditions.

Three additional tests are scheduled in July and August before the initial series is completed.

Robert Pearlman
Editor

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From: Houston, TX
Registered: Nov 1999

posted 07-18-2015 12:03 PM     Click Here to See the Profile for Robert Pearlman   Click Here to Email Robert Pearlman     Edit/Delete Message   Reply w/Quote
NASA video release
Pedal to the Metal – RS-25 Engine Revs Up Again

In auto racing parlance, NASA engineers put the "pedal to the metal" during a July 17 test of its Space Launch System (SLS) RS-25 rocket engine at Stennis Space Center.

During a 535-second test, operators ran the RS-25 through a series of power levels, including a period of firing at 109 percent of the engine's rated power. Data collected on performance of the engine at the various power levels will aid in adapting the former space shuttle engines to the new SLS vehicle mission requirements, including development of an all-new engine controller and software.

Two additional tests of the RS-25 engine are planned before the current test series concludes by early September and a new test series begins on four engines for a future flight.

See here for discussion of RS-25 engine use for the Space Launch System.

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