posted 01-12-2012 06:02 PM               

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.

posted 06-09-2013 10:03 AM               

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.

posted 04-11-2014 04:01 PM               

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.

posted 07-17-2014 12:30 PM               

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.

posted 01-09-2015 07:42 PM               

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.

posted 05-28-2015 02:21 PM               

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."

posted 05-29-2015 06:40 AM               

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.

posted 06-11-2015 10:13 PM               

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.

posted 06-26-2015 07:48 AM               

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.

posted 07-18-2015 12:03 PM               

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.

posted 08-14-2015 09:34 AM               

Countdown to Deep Space Continues with Latest RS-25 Test

NASA's countdown to deep space continued Thursday (Aug. 13) with a 535-second test of its Space Launch System (SLS) RS-25 rocket engine to collect engine performance data at NASA's Stennis Space Center near Bay St. Louis, Mississippi. SLS will launch astronauts in the Orion spacecraft on missions to deep space and eventually on the journey to Mars.

Operators on the A-1 Test Stand at Stennis are conducting the test series to qualify an all-new engine controller and put the upgraded former space shuttle main engines through the rigorous temperature and pressure conditions they will experience during a SLS mission.

One final test of this RS-25 developmental engine is planned in this series; testing of flight engines begins later this fall.

More than 1,200 people, including elected officials and community leaders, media and social media representatives, and NASA and contractor employees and family members viewed the test. Guests saw Stennis facilities and test stands, the Aerojet Rocketdyne engine assembly facility, and the Pegasus barge that will transport the SLS core stage from NASA's Michoud Assembly Facility in New Orleans to Stennis for testing then to Kennedy Space Center in Florida for launch.

An initial 70-metric-ton (77-ton) SLS configuration will use four RS-25 engines for the core stage, along with two five-segment solid rocket boosters, providing more lift to orbit than any current launch vehicle. The core stage for the first SLS and Orion integrated flight — Exploration Mission-1 — also will be tested at Stennis. That test will involve simultaneous firing of the four RS-25 engines just as during an actual launch.

The RS-25 engine gives SLS a proven, high performance, affordable main propulsion system for deep space exploration. It is one of the most experienced large rocket engines in the world, with more than a million seconds of ground test and flight operations time. Aerojet Rocketdyne of Sacramento, California, is the prime contractor for the RS-25 engine work.

posted 08-27-2015 04:53 PM               

NASA Concludes Series of Engine Tests for Next-Gen Rocket

NASA has completed the first developmental test series on the RS-25 engines that will power the agency's new Space Launch System (SLS) rocket on missions deeper into space than ever before.

The test series wrapped up Thursday with a seventh hot fire test of a developmental RS-25 engine on the A-1 Test Stand at NASA's Stennis Space Center in Bay St. Louis, Mississippi. The test ran for a full-duration 535 seconds.

"The completion of this test series is an important step in getting SLS ready for the journey to Mars," said Steve Wofford, engines manager at NASA's Marshall Space Flight Center in Huntsville, Alabama, where the SLS Program is managed for the agency. "The RS-25 engine gives SLS a proven, high performance, affordable main propulsion system. It is one of the most experienced large rocket engines in the world, with more than a million seconds of ground test and flight operations time."

The series was designed to collect valuable data on performance of the RS-25 engine, a former space shuttle main engine operating at higher thrust levels in order to provide the power needed for the SLS vehicle. Of particular interest is data that will aid in development of a new engine controller, or "brain," to monitor engine status and communicate programmed performance needs.

"These are extremely reliable engines. We are testing them again because we want to ensure that the engine performs as required with a new engine controller, higher propellant inlet pressures and lower temperatures that are part of the SLS design. We also want to mitigate any risks on the ground before flight," Wofford said.

Four RS-25 engines will help power the SLS core stage during launch. Firing simultaneously at 109 percent of its operating level, the engines will provide approximately 2 million pounds of thrust. The engines will operate in conjunction with a pair of five-segment solid rocket boosters for a total of 8.4 million pounds of thrust to lift the initial 70-metric-ton (77-ton) SLS off the launch pad. The SLS eventually will evolve to a 130-metric-ton (143-ton) configuration that will enable missions to such deep space destinations as an asteroid and Mars.

Testing of RS-25 flight engines for the initial SLS missions will begin at Stennis this fall. In addition to testing RS-25 flight engines, Stennis operators will employ their collective expertise to test the SLS core stage. The B-2 Test Stand at Stennis is being renovated to conduct tests on the SLS flight core stage prior to its first uncrewed mission. That testing will involve installing the flight stage on the stand and firing its four RS-25 engines simultaneously, just as during an actual launch.

"What a great time to be at Stennis," Center Director Rick Gilbrech said. "When it comes to powering the future of the deep space exploration program for this country, this is the front lines, where we enable those missions to fly."

The developmental tests began with a Jan. 9 hot fire and resumed in May after scheduled work was completed on the high-pressure industrial water system that provides the thousands of gallons of water needed during an engine test. Aerojet Rocketdyne of Sacramento, California, is the prime contractor for the RS-25 engine work.

"This was a great test series for Stennis," said Ronnie Rigney, RS-25 project manager at Stennis. "Our teams built up a lot of history with space shuttle main engines and were able to use that expertise to meet very challenging test specifications for the RS-25. The testing done here will help ensure the engines perform as needed during actual SLS missions."

posted 11-04-2015 04:22 PM               

Getting Ready to Fly

NASA took the next big step on its Journey to Mars on Nov. 4 by placing the first RS-25 flight engine, engine No. 2059, on the A-1 Test Stand at Stennis Space Center. The engine will be tested in the first part of 2016 to certify it for use on NASA’s new Space Launch System (SLS).

The core stage for the 2018 SLS flight – Exploration Mission-1 – also will be tested at Stennis. Testing will involve installing the flight stage on the B-2 test stand and firing its four RS-25 engines simultaneously, just as during an actual launch.

The SLS Program has an inventory of 16 RS-25 flight engines, built by Aerojet Rocketdyne of Sacramento, California. The engines are available for the first four SLS missions, and two development engines are available for ground tests.

These engines are being adapted to SLS performance requirements, including improvements like nozzle insulation and a new electronic controller.

posted 03-11-2016 12:28 AM               

Engine used on penultimate space shuttle flight relit for NASA's new rocket

A rocket engine that helped launch five space shuttle missions, including the penultimate flight of the program in 2011, was fired again on Thursday (March 10) in preparation for the first crewed flight of NASA's new heavy-lift rocket.

The space agency successfully test fired the RS-25 rocket engine for a full 500 seconds, clearing a milestone towards its exploration goals. The next time that particular engine, serial number 2059, fires for that length of time, it will be to launch astronauts on NASA's first crewed mission beyond Earth orbit since the last of the Apollo moon missions more than 45 years ago.

"What a great moment for NASA," said Rick Gilbrech, the director of NASA's Stennis Space Center in Bay St. Louis, Mississippi, where Thursday's hot fire test took place. "We have exciting days ahead with a return to deep space and a journey to Mars, and this test is a very big step in that direction."

posted 08-01-2016 10:10 AM               

NASA Marches on with Test of RS-25 Engine for New Space Launch System

NASA engineers conducted a successful developmental test of RS-25 rocket engine No. 0528 July 29, 2016, to collect critical performance data for the most powerful rocket in the world — the Space Launch System (SLS). The engine roared to life for a full 650-second test on the A-1 Test Stand at NASA's Stennis Space Center, near Bay St. Louis, Mississippi, marking another step forward in development of the SLS, which will launch humans deeper into space than ever before, including on the journey to Mars.

Four RS-25 engines, joined with a pair of solid rocket boosters, will power the SLS core stage at launch. The RS-25 engines used on the first four SLS flights are former space shuttle main engines, modified to operate at a higher performance level and with a new engine controller, which allows communication between the vehicle and engine.

NASA conducted a series of developmental tests on the engine last year before testing a flight engine that will be used on its second test flight, known as Exploration Mission-2 (EM-2). EM-2 will be the first crewed flight of NASA's Orion spacecraft, launching on the SLS. A second series of developmental tests began July 14. The test was conducted by a team of NASA, Aerojet Rocketdyne and Syncom Space Services engineers and operators. Aerojet Rocketdyne is the prime contractor for the RS-25 engines. Syncom Space Services is the prime contractor for Stennis facilities and operations.

The July 29 test and four future scheduled firings in the current series are focused on the new engine controller and higher operating parameters. While RS-25 engines are among the most tested — and proven — in the world, they have been modernized for SLS.

The developmental tests are designed to show they will meet the new parameters of the rocket. During the firings, the test team will put the engine through a variety of adaptations, starting it at different temperatures and pressures, for instance. The team also will watch closely to ensure the new engine controller functions as needed.

In addition to the existing RS-25 engines, NASA has contracted with Aerojet Rocketdyne to build additional engines for use on SLS missions. All flight testing for SLS take place at Stennis, as will the actual core stage testing for the first integrated mission of SLS and NASA's Orion spacecraft, Exploration Mission-1.

The next scheduled RS-25 developmental test at Stennis is set for Aug. 18.

posted 08-19-2016 12:15 AM               

NASA Continues Progress on the Journey to Mars with Latest RS-25 Rocket Engine Test

NASA engineers successfully conducted a development test of the RS-25 rocket engine Thursday, Aug. 18 at NASA's Stennis Space Center near Bay St. Louis, Miss.

A variety of NASA officials and contractor representatives, as well as social and traditional media members, gathered to watch the 420-second test of RS-25 engine No. 0528.

During the test, the engine was run through a range of varying conditions and operating parameters. For instance, operators used an extended low-flow chill down process for the engine prior to the test and also experimented with a high-pressure start process. A special engine controller wiring configuration was tested, and the engine was fired at ranges of 80 to 111 percent power during the test. Test data on engine and controller performance was provided by the facility team at twice the normal rate.

This latest test marks the third in a six-test developmental series. NASA tested RS-25 engine No. 2059 in March for use as a flight engine on the second integrated test flight of SLS with the agency's Orion spacecraft, known as Exploration Mission-2, which will carry a crew aboard the space capsule for the first time.

The latest developmental series of tests began with a July 14 firing, followed by a July 29 test. Future tests are scheduled for this fall and also will focus on gathering performance data on the engine and its new controller.

posted 02-22-2017 05:08 PM               

NASA engineers conducted their first RS-25 test of 2017 on the A-1 Test Stand at Stennis Space Center near Bay St. Louis, Mississippi, on Feb. 22, continuing to collect data on the performance of the rocket engine that will help power the new Space Launch System (SLS) rocket.

Shown from the viewpoint of an overhead drone, the test of development engine No. 0528 ran the scheduled 380 seconds (six minutes and 20 seconds), allowing engineers to monitor various engine operating conditions.

posted 03-27-2017 07:04 AM               

NASA Engineers Conduct a Test of the First RS-25 Engine Controller at Stennis Space Center

NASA engineers conducted a test of the first RS-25 engine controller that will be used on an actual Space Launch System flight on the A-2 Test Stand at Stennis Space Center on March 23. The RS-25 engine, with the flight controller, was test fired for a full-duration 500 seconds.

The engine controller, which was installed on RS-25 development engine no. 0528 for the test, is a modern version from the controller that helped propel all of the space shuttle missions. The controller manages the engine by regulating the thrust and fuel mixture ratio and monitors the engine's health and status.

posted 05-24-2017 04:02 PM               

NASA’s Space Launch System Engine Testing Heats Up

NASA engineers successfully conducted the second in a series of RS-25 flight controller tests on May 23, 2017, stepping closer to deep-space exploration with the world’s most-powerful rocket.

The test was set after a facility issue, subsequently resolved, forced rescheduling of a May 16 hot fire. The 500-second — more than eight full minutes — test on the A-1 Test Stand at NASA’s Stennis Space Center in Mississippi marked another milestone toward launch of NASA’s new Space Launch System (SLS) rocket on its inaugural flight, known as Exploration Mission-1 (EM-1).

The RS-25 engines for the initial flight are former space shuttle main engines, modified to perform at a higher level and with a new controller. The controller is the key modification to the engines. The component is often cited as the RS-25 “brain” that allows communication between the engine and the rocket. Prior to a flight, engine performance specifications, such as percentage of thrust needed, are programed into the controller. The controller then communicates the specifications and ensures these are being met by monitoring and controlling such factors as propellant mixture ratio and thrust level.

Stennis performed an earlier series of tests to gather data for development of the new controller, which is a collaborative effort of NASA, RS-25 prime contractor Aerojet Rocketdyne of Sacramento, Calif. and subcontractor Honeywell of Clearwater, Fla. The first flight controller was tested in March at Stennis for installation on one of the four EM-1 engines.

Pending data review from the May 23 test, the second flight controller will be installed on SLS for EM-1. A third flight controller is scheduled for testing in July at Stennis.

Tests are conducted by a team of NASA, Aerojet Rocketdyne and Syncom Space Services engineers and operators. Syncom Space Services is the prime contractor for Stennis facilities and operations.

posted 07-26-2017 07:24 AM               

Aerojet Rocketdyne's RS-25 Flight Controller Goes Three for Three in Testing for NASA's Space Launch System

Aerojet Rocketdyne successfully tested its third RS-25 engine flight controller today (July 25) at NASA's Stennis Space Center in Mississippi. The RS-25 engine will propel America's next-generation heavy lift rocket, the Space Launch System (SLS), into space. The flight controller tested today is slated to fly on the inaugural mission of the SLS which will propel the Orion capsule around the Moon and safely return it back to Earth.

"The Space Launch System is the rocket that will take humans beyond the Moon, and ultimately to Mars," said Aerojet Rocketdyne CEO and President Eileen Drake. "Evaluating the engine's flight controller under multiple conditions is one way we are ensuring that we are providing a safe, reliable engine to the nation for its deep space exploration efforts."

The flight controller translates the vehicle's commands into action while monitoring the health of the engine by making real-time adjustments to the speed of the turbopumps, combustion pressures, as well as the engine's thrust and propellant mixture ratios. Today's test focused on the engine thrust and mixture ratio precision operation.

"Achieving the optimum thrust and mixture ratio is crucial for creating an extremely efficient rocket engine," added Dan Adamski, RS-25 program director at Aerojet Rocketdyne. "The RS-25 is the most efficient booster engine in the world, which is why it is the right engine for human exploration of deep space."

Four RS-25 engines power the core stage of the SLS for 8½ minutes to help the SLS during its climb to space; combined, the engines provide the rocket with more than two million pounds of thrust. The SLS rocket provides an unmatched capability to launch the heaviest and largest payloads faster to any destination when compared with other existing or proposed launch vehicles in development, making it the ideal rocket to explore deep space.

posted 08-09-2017 05:38 PM               

NASA on a Strong Roll in Preparing Space Launch System Flight Engines

Just two weeks after the third test of a new RS-25 engine flight controller, NASA recorded its fourth full-duration controller test Aug. 9 at Stennis Space Center near Bay St. Louis, Mississippi.

Engineers conducted a 500-second test of the RS-25 engine controller on the A-1 Test Stand at Stennis. The test involved installing the controller on an RS-25 development engine and firing it in the same manner, and for the same length of time, as needed during an actual SLS launch. The test marked another milestone toward launch of the first integrated flight of the SLS rocket and Orion crew vehicle.

posted 01-17-2018 07:43 AM               

Aerojet Rocketdyne RS-25 Test Advances Exploration Efforts

Today [Jan. 16], NASA and Aerojet Rocketdyne hot-fired an RS-25 engine in a test that marked another milestone toward the first crewed flight of the agency's Space Launch System (SLS) while laying groundwork for future production of the heavy-lift launch vehicle's main propulsion system.

The 365-second test at NASA's Stennis Space Center near Bay St. Louis, Mississippi qualified the controller for the third of four RS-25 engines that will power the SLS first stage on Exploration Mission-2 (EM-2), which will send astronauts to an area near the Moon in the early 2020s. It will be humankind's first foray beyond low Earth orbit in nearly 50 years.

Also on the test engine was an additively manufactured component designed to dampen engine vibrations that could create stability issues during flight. The pogo accumulator assembly, the engine's largest additively manufactured component to date, has now performed successfully on two successive RS-25 hot fire tests. The first test was on Dec. 13, 2017.

"Aerojet Rocketdyne is playing a vital role in the nation's effort to expand the frontiers of humankind," said Eileen Drake, Aerojet Rocketdyne's CEO and president. "This test is the latest example of our steady progress, not only toward EM-2 but also toward putting the nation's exploration program on a sustainable path for the future."

Additive manufacturing is a key element of Aerojet Rocketdyne's plan to reduce the manufacturing costs of future versions of the RS-25 by 30 percent. The RS-25 engine is based on the Space Shuttle Main Engine that powered NASA's space shuttles into orbit. Future versions will incorporate design simplifications and modern manufacturing processes such as additive manufacturing for affordability and sustainability.

The RS-25 program has 16 engines left in its inventory from the space shuttle program that are currently being repurposed for SLS, which will make its debut in 2019 carrying an uncrewed version of NASA's Orion spacecraft.

These legacy engines are being upgraded and modernized for the first four flights of the SLS. Thrust is being increased from 491,000 pounds on space shuttle missions to 512,000 pounds for SLS. The new controller – essentially the brain of the engine – weighs less and has far more processing power than previous versions, making the engine more responsive to vehicle commands.

"We ended 2017 with a successful engine test in December and have now maintained that momentum into 2018," said Dan Adamski, RS-25 program director at Aerojet Rocketdyne. "Future testing this year will continue to add to the program's inventory of flight controllers and will bring additional development hardware into the test program to demonstrate design, manufacturing and affordability improvements. Our pogo accumulator assembly is just one of the first of these efforts to be hot-fire tested."

posted 02-03-2018 08:25 PM               

NASA Conducts Second RS-25 Engine Hot Fire Test of 2018

NASA followed up the first RS-25 test of 2018 with a second hot fire of the Space Launch System (SLS) engine on Feb. 1 at Stennis Space Center near Bay St. Louis, Mississippi. The full-duration, 365-second certification test of another RS-25 engine flight controller on the A-1 Test Stand at Stennis comes about two weeks after a Jan. 16 hot fire. The test marks completion of green run testing for all four of the new RS-25 engine flight controllers needed for the second flight of NASA's SLS rocket. NASA is building SLS to send humans to such deep-space destinations as the moon and Mars.

The Exploration Mission-1 (EM-1) flight will test the new rocket and carry an uncrewed Orion spacecraft into space beyond the moon. Exploration Mission-2 (EM-2) will be the first flight to carry humans aboard the Orion spacecraft, returning astronauts to deep space for the first time in more than 40 years.

RS-25 controllers for the EM-1 flight already are installed on the engines that will be part of the SLS core stage. In addition to the flight controller, the Feb. 1 hot fire at Stennis also marked the third test of a 3D-printed pogo accumulator assembly for the RS-25 engine. Testing of the 3D-printed component is part of an ongoing effort to use advanced manufacturing techniques and processes as a means of reducing engine construction costs. NASA plans to test a number of 3D-printed components for the RS-25 engine.

For the recent test, flight controller ECU 11 was installed on RS-25 developmental engine E0528 and fired under conditions akin to an actual launch. Each RS-25 hot fire is designed to test and evaluate the performance of the engine and its components in specific scenarios. Typically, an engine is cycled through various thrust levels that may be needed during flights to help engineers gather as much performance data as possible. Once certified, tested flight controllers are removed for installation on flight engines for the SLS rocket.

All RS-25 engines and flight controllers for SLS missions are being tested at Stennis, as is the flight core stage for the first SLS mission. SLS core stage testing will involve installing the stage on the B-2 stand at Stennis and firing all four of the RS-25 engines simultaneously. At launch, the four RS-25 engines will fire simultaneously to generate 2 million pounds of thrust and working in conjunction with a pair of solid rocket boosters to produce more than 8 million pounds of thrust. RS-25 engines for initial SLS flights are former space shuttle main engines, modified to provide additional power to launch the larger SLS rocket.

The new flight controller is a key component of that modification, serving as the RS-25 "brain" to help the engine communicate with the SLS rocket and to help control engine operation and internal health diagnostics. RS-25 tests at Stennis are conducted by a team of NASA, Aerojet Rocketdyne and Syncom Space Services engineers and operators. Aerojet Rocketdyne is the RS-25 prime contractor. Syncom Space Services is the prime contractor for Stennis facilities and operations.

posted 10-12-2018 12:58 PM               

The third in a series of RS-25 rocket engine hot fire tests for NASA’s Space Launch System (SLS) Program was conducted September 25 at NASA's Stennis Space Center.

The test was another certification of an RS-25 flight controller that helps the engine communicate with the SLS rocket. It also marked the seventh test of a 3D-printed pogo accumulator assembly that helps prevent the rocket from becoming unstable in flight and the third test of a main combustion chamber fabricated using a new money- and time-saving bonding technique.

posted 04-09-2019 12:59 PM               

NASA Achieves Rocket Engine Test Milestone Needed for Moon Missions

NASA is a step closer to returning astronauts to the Moon in the next five years following a successful engine test on Thursday (April 4) at NASA's Stennis Space Center near Bay St. Louis, Mississippi. The latest "hot fire" was the culmination of four-plus years of testing for the RS-25 engines that will send the first four Space Launch System (SLS) rockets into space.

Above: NASA conducts a test of RS-25 flight engine No. 2062 on April 4 on the A-1 Test Stand at Stennis Space Center near Bay St. Louis, Miss. The test marked a major milestone in NASA's march forward to Moon missions. All 16 RS-25 engines that will help power the first four flights of NASA's new Space Launch System rocket now have been tested.

"This completes four years of focused work by an exceptional Stennis test team," Stennis Director Rick Gilbrech said. "It represents yet another chapter in Stennis' long history of testing leadership and excellence in support of this nation's space exploration efforts. Everyone involved should feel proud of their work and contributions."

Thursday's hot fire on Stennis' A-1 Test Stand completed:

• Acceptance testing of all 16 former space shuttle main engines that will help launch the first four SLS missions. NASA has contracted with Aerojet Rocketdyne to build new RS-25 engines for additional SLS missions, and work already is underway to do so in the company's factory in Canoga Park, California.
  
• Developmental and flightworthy testing for new controllers (plus one spare) to be used by the heritage RS-25 engines for the first four missions.
  
• A 51-month test series that demonstrated RS-25 engines can perform at the higher power level needed to launch the super heavy-lift SLS rocket.

"Engines are now a 'go' for missions to send astronauts forward to the Moon to learn and prepare for missions to Mars," said Johnny Heflin, deputy manager of the SLS Liquid Engines Office at NASA's Marshall Space Flight Center in Huntsville, Alabama. "We're ready to provide the power to explore the Moon and beyond."

The RS-25 rocket engine test era began Jan. 9, 2015, with a 500-second – more than 8 minutes – hot fire of RS-25 developmental engine No. 0525 on the A-1 Test Stand at Stennis. NASA tested the first SLS flight engine on March 10, 2016. Altogether, the agency has conducted 32 developmental and flight engine tests for a total of 14,754 seconds – more than four hours – of cumulative hot fire – all on the A-1 stand at Stennis.

Having launched 135 space shuttle missions, these main engines are considered the most tested engines in the world. When the Space Shuttle Program ended in 2011, NASA still had 16 engines that ultimately were modified for SLS.

These engines were originally designed to perform at a certain power level, known as 100 percent. Over time, the engines were upgraded to operate at higher and higher power levels, up to 104.5 percent operating power level by the end of the shuttle program. For SLS, that operating level has to be pushed even higher.

To help accomplish that, and to interface with new rocket avionics systems, NASA designed and tested a new engine controller, which serves as the "brain" of the engine to help monitor engine operation and facilitate communication between the engine and rocket. Early developmental testing at Stennis provided critical information for designing the new controller.

Above: RS-25 flight engine No. 2062 is lifted onto the A-1 Test Stand at NASA's Stennis Space Center near Bay St. Louis, Miss. The Aerojet Rocketdyne-built engine was delivered to the stand March 20 and test fired April 4.

The first new flight engine controller was tested at Stennis in March 2017, with a string of controller hot fires to follow. The April 4 test marked the testing of the 17th engine controller for use on SLS flights, providing enough for all 16 heritage RS-25 engines.

With development of the new controllers, NASA had to test the new power level as well. First, it was demonstrated that the engine could perform at the needed 111 percent power level. Next, NASA needed to prove a margin of operating safety.

In February 2018, operators pushed the engine to 113 percent power for a total of 50 seconds. It lengthened that firing time in two subsequent tests, until late this February, when the engine was fired at 113 percent power for 430 seconds of a 510-second test.

That set the stage for Thursday's successful test of flight engine No. 2062. When this specific engine fires again, it will help send astronauts aboard Orion around the Moon on a test flight known as Exploration Mission-2.

posted 01-27-2021 09:29 PM               

NASA to Begin New RS-25 Engine Test Series for Future Artemis Missions

NASA is set to begin a new round of tests for development of RS-25 engines that will help power the agency's Space Launch System (SLS) rocket on future missions to the Moon and, eventually, Mars. The first test of the new series is set for Jan. 28 on the A-1 Test Stand at Stennis Space Center near Bay St. Louis, Mississippi.

Above: RS-25 developmental engine No. 0528 is hoisted onto the A-1 Test Stand at Stennis Space Center on Nov. 19, 2020. Operators have scheduled a hot fire test of the engine, in reparation for a new series of tests focused on providing data for the development of new RS-25 engines for future Space Launch System missions.

The seven-test series will use RS-25 developmental engine No. 0528 and will provide valuable data for Aerojet Rocketdyne, prime contractor for the SLS engines, as it begins production of new RS-25 engines for use after the first four SLS flights. Operators will focus on evaluating new engine components and reducing risk in engine operation. They also will fire the engine through a range of operating conditions to demonstrate and verify its capabilities.

The upcoming test series will provide data to enhance production of new RS-25 engines and several engine components that are being manufactured with cutting-edge and cost-saving technologies. Operators also will demonstrate engine gimbaling capabilities, using a newly installed A-1 Test Stand thrust vector control system. "Gimbaling" refers to how the engine must move on a tight circular axis in order to ensure proper flight trajectory.

"We're going to evaluate these newly designed parts that were made using advanced manufacturing techniques," said Johnny Heflin, SLS liquid engines manager at Marshall Space Flight Center in Huntsville, where the SLS Program is based. "This test series will prove that the RS-25 production restart engines can be built with the same high performance but with more affordability. This is a big milestone that will greatly contribute to the future sustainability of SLS."

Resumption of RS-25 single-engine testing on the A-1 Test Stand follows completion of major maintenance work on the facility originally built for Apollo Program testing more than 50 years ago. Projects designed to ensure the facility continues functioning at a high level included upgrading piping and the test stand flame deflector, painting the 40,000-gallon liquid oxygen 100,000-gallon liquid hydrogen tanks, remodeling the Test Control Center, and upgrading the data acquisition system, facility cameras, and facility control systems. The new NASA-designed-and-manufactured thrust vector control system also was finalized and installed during this time.

"It is exciting to return to hot fire testing at the A-1 Test Stand," Stennis RS-25 Project Manager Chip Ellis said. "We have worked hard the last 20 or so months to complete needed test stand maintenance projects. Now, the team is ready to get back to the business of testing for future deep space missions."

The engine will be fired seven times for a total of 3,650 seconds during the first half of 2021. The schedule calls for six full-duration tests of about eight and a half minutes (500 seconds) and one hot fire of just under 11 minutes (650 seconds). A full duration test refers to the time the engine must fire during an actual launch in order to power SLS towards orbit. Longer duration hot fires are conducted to test the limits of engine performance.

For about half of the firing time, the engines will operate at 111 of the power level at which the original space shuttle main engines were designed to perform. Operators will also demonstrate operation at the 113 percent power level for an extended period, as was initially demonstrated in a Feb. 2018 hot fire.

The previous round of RS-25 testing concluded April 4, 2019 and focused primarily on validating new operating parameters for the initial RS-25 engines, which are modified heritage space shuttle main engines, and included acceptance testing of 16 former space shuttle main engines that will help launch the first four SLS missions. This new RS-25 test series begins as a separate test series, called Green Run, is in its final phase. The Green Run is a comprehensive series of tests of the core stage of the SLS rocket, which includes four RS-25 engines, and culminates with a final test to fire all four together for about eight minutes. The Green Run team recently fired all four RS-25 engines together for the first time and is currently evaluating if a second hot fire test is required.

posted 01-28-2021 07:33 PM               

Watch an RS-25 engine that will help power our Space Launch System rocket on future missions to the Moon and Mars come alive at NASA's Stennis Space Center.

posted 12-13-2022 04:05 PM               

NASA Begins New RS-25 Engine Testing for Future Artemis Missions

NASA will begin a new series of hot fire testing Dec. 14 at Stennis Space Center near Bay St. Louis, Mississippi, to support production of future RS-25 engines to help power the Space Launch System (SLS) rocket on Artemis missions to the Moon and beyond.

Above: RS-25 engine, E10001, is delivered to the Fred Haise Test Stand at NASA’s Stennis Space Center on Nov. 15 in preparation for an initial confidence test hot fire the following month. (NASA/SSC)

The hot fire test, which is expected to run for 500 seconds, will be livestreamed on NASA Stennis Space Center Facebook and YouTube pages beginning shortly prior to ignition. The test window is set to open at 2 p.m. CST.

The initial single-engine hot fire, known as a confidence test, is designed to confirm all is ready to proceed with a series of certification tests early next year on a full RS-25 certification engine.

"It is exciting to return to hot fire testing at the historic Fred Haise Test Stand and get back to the business of testing for future Artemis missions," said NASA Stennis RS-25 project manager Chip Ellis.

The test will provide initial data to aid NASA and lead SLS engines contractor Aerojet Rocketdyne as the company prepares to begin production of new RS-25 engines to power future Artemis missions to the Moon and eventual journeys to Mars. For each SLS flight, four RS-25 engines, along with a pair of solid rocket boosters and core stage, help power the rocket at liftoff. NASA and the company modified 16 of the engines remaining after the Space Shuttle Program for use on Artemis mission I through IV. The upcoming series of testing is for the RS-25 engines that will be used beginning with Artemis V.

The confidence hot fire test is expected to run about eight-and-a-half minutes (500 seconds) the length of time engines must fire during an actual flight. The engine will operate up to 111% power level, the same level needed to help power SLS, for most of the test. It will briefly throttle down to 80% before boosting back to 111%, then slowing down again to conclude testing.

Future RS-25 engines will feature a range of new components, most of which are installed for the Dec. 14 hot fire. The upcoming certification test series will validate the overall engine design and how these new engine features perform together.

"We're looking forward to this upcoming hot fire test to verify our design but also to ensure we have the most robust engine possible," said Andy Ketchum, Aerojet Rocketdyne's RS-25 test and flight operations manager. "The December 14 engine test is focused on evaluating how components like the new powerhead, low-pressure oxidizer, and fuel turbopumps perform together before we add the new nozzle and controller into the mix."

The end-of-year hot fire marks a return to RS-25 testing at Stennis since NASA completed its developmental test effort in March. Developmental work included several test series to collect data for Aerojet Rocketdyne as the company modernizes manufacturing processes and reduces production costs of new RS-25 engines.

The Dec. 14 test also follows multiple upgrades made in recent months to the Fred Haise Test Stand. The projects included installation of new test stand piping, drilling a special flame bucket hole pattern to help cool RS-25 engine exhaust, and updating the stands thrust vector control and data acquisition systems.

Every RS-25 engine that will help power the SLS rocket at launch for Artemis missions will be tested at Stennis, including those that will send the first woman and the first person of color to the Moon.

posted 02-09-2023 03:27 PM               

NASA Conducts First 2023 Test of Redesigned Moon Rocket Engine

NASA's newly redesigned RS-25 engine for future flights of the Space Launch System (SLS) rocket, underwent its first hot fire test of the year on Feb. 8 at the agency's Stennis Space Center near Bay St. Louis, Mississippi.

Above: NASA conducts an RS-25 hot fire on the Fred Haise Test Stand at Stennis Space Center in south Mississippi on Feb. 8, 2023

The series of testing supports production of new RS-25 engines by lead SLS engine contractor Aerojet Rocketdyne. The new engines will help power future Artemis missions to the Moon beginning with Artemis V as NASA explores the universe for the benefit of all.

The single-engine hot fire on the Fred Haise Test Stand followed a confidence test in 2022, which tested whether all was ready to proceed with the certification series.

During the latest test, engineers fired the RS-25 engine for a full duration of about eight and a half minutes (500 seconds), the same amount of time the engines must operate to help power SLS to space. The RS-25 engine also operated at 111% power for most of the test, the same level needed to help lift SLS to orbit. The test featured a range of new components, most of which were installed for the December hot fire. One additional component – a new nozzle – was installed prior to the most recent hot fire.

Four RS-25 engines fire simultaneously to generate a combined 1.6 million pounds of thrust at launch and 2 million pounds of thrust during ascent to help power each SLS flight. NASA and Aerojet Rocketdyne modified 16 engines remaining from the Space Shuttle Program, which were proven flightworthy at Stennis for Artemis missions I through IV.

Every RS-25 engine that will help power SLS will be tested at NASA Stennis. RS-25 tests at the site are conducted by a combined team of NASA, Aerojet Rocketdyne, and Syncom Space Services operators. Syncom Space Services is the prime contractor for Stennis facilities and operations.

posted 02-24-2023 05:15 PM               

NASA Continues Testing Redesigned Artemis Moon Rocket Engines

Engineers hot fire tested a redesigned RS-25 engine Feb. 22 for future flights of the Space Launch System (SLS) rocket on Artemis missions to the Moon.

The test, conducted on the Fred Haise Test Stand at NASA's Stennis Space Center near Bay St. Louis, Mississippi, is part of a certification series to support production of new RS-25 engines by lead SLS engines contractor Aerojet Rocketdyne. As NASA explores the secrets of the universe for the benefit of all, the new engines will help power future Artemis missions, beginning with Artemis V.

Operators fired the RS-25 engine up to 111% power level – the same level needed to help the SLS lift the Orion spacecraft and other future payloads to orbit – for 10 minutes (600 seconds), more than the 500 seconds the engines must operate to reach space. Longer-duration hot fires allow operators to test the limits of engine performance and provide a margin of safety for flight operations.

The hot fire is the latest in an ongoing series of tests to certify new manufacturing techniques and processes for production of RS-25 engines. Four engines fire simultaneously, providing up to 2 million pounds of combined thrust, to help power the launch of the SLS to orbit.

At the end of the Space Shuttle Program, NASA had 16 remaining main engines, some of the most sophisticated and proven in the world. The agency decided to upgrade the engines for use on the SLS.

In January 2015, NASA Stennis began testing to enable the engines to provide additional power needed to launch the SLS rocket. Among other modifications, Aerojet Rocketdyne provided the engines with a new controller – or "brain" – to monitor performance.

In 2019, NASA contracted with Aerojet Rocketdyne to produce new RS-25 engines for future SLS missions beyond Artemis IV, to be manufactured with advanced processes, such as 3D printing, to reduce production time and costs. NASA began developmental testing in May 2020 to provide performance data for the new processes, and NASA Stennis upgraded its Fred Haise Test Stand last year to prepare for the new round of testing.

On Feb. 8, NASA conducted the first test of a newly redesigned RS-25 engine. The subsequent 12-test series will demonstrate that Aerojet Rocketdyne is prepared to produce engines for future missions.

Through ongoing Artemis missions, NASA will send humans to the Moon to establish a sustainable presence and prepare for missions to Mars. The agency plans to establish an orbiting Gateway habitat orbiting the Moon and develop the techniques and capabilities needed for journeys to other deep space destinations.

Every RS-25 engine that helps power SLS will be tested at NASA Stennis. RS-25 tests at the site are conducted by a combined team of NASA, Aerojet Rocketdyne, and Syncom Space Services operators. Syncom Space Services is the prime contractor for Stennis facilities and operations.

posted 03-09-2023 02:05 PM               

NASA Continues Test Series for Redesigned Artemis Moon Rocket Engines

NASA's testing for redesigned RS-25 engines to be used on future Space Launch System (SLS) missions continued with a March 8 full-duration hot fire at NASA's Stennis Space Center, near Bay St. Louis, Mississippi.

The test, conducted on the Fred Haise Test Stand at NASA Stennis, was the third of the year and part of an ongoing certification hot fire series. It also was the third test since an upgraded nozzle was installed on the RS-25 engine just prior to a Feb 8 hot fire. The redesigned engines provided by lead SLS engines contractor Aerojet Rocketdyne will be used on future Artemis flights to the Moon, beginning with Artemis V, as NASA continues its mission to explore the secrets of the universe for the benefit of all.

"Early indications are that the nozzle is working well," said Mike Lauer, deputy program manager of RS-25 engines at Aerojet Rocketdyne. "Even though we changed manufacturing methods, we did not want to radically change the performance of the nozzle. We are very pleased that the nozzle appears to be performing very much in line with our previous history."

Operators fired the RS-25 engine during the test for a scheduled 520 seconds and up to 113% power level. During missions to the Moon, engines fire for about 500 seconds and up to the 111% power level to help SLS lift the Orion spacecraft and other payloads to orbit. With added seconds and the increased power level during ground tests, engineers can learn more about engine performance and provide a margin of operational safety.

The nozzle, or bell-shaped part at the bottom of the RS-25 engine, helps generate thrust by ejecting the engine's exhaust at maximum speed to propel SLS to space. It is one of multiple upgraded components on the redesigned engine and also critical in ensuring efficiency by using a minimum amount of propellants, or fuel, to generate thrust and help propel the rocket to space. The nozzle is one reason the RS-25 is one of the most fuel-efficient rocket engines in the world.

Above: A mounted field camera offers a close-up views as NASA conducts an RS-25 hot fire test on the Fred Haise Test Stand at NASA’s Stennis Space Center in south Mississippi on March 8, 2023. (NASA/Stennis)

Over the course of the storied history of the RS-25 engine, many components have gone through changes or upgrades. One component that mostly went unchanged was the nozzle.

For redesigned RS-25 engines, however, a team focused on re-engineering every part of the nozzle. This included using precision machining to improve production of the more than 1,000 tubes that comprise the nozzle wall. These tubes are critical in flowing super-cold liquid hydrogen to keep the nozzle cool. The team also is using 3D printing to manufacture selected nozzle parts.

Upgrades to the nozzle include a new type and amount of insulation, which is a critical consideration since the RS-25 engines are exposed to more heat during SLS launches than previous space shuttle missions. SLS features four RS-25 engines instead of the three main engines used for the space shuttle and the proximity of the RS-25 nozzle to the SLS solid rocket boosters is closer than on the space shuttle.

The goal of the upgrades is to streamline the nozzle production process, while making it more cost efficient and still achieving the same performance level as with previous RS-25 engines. While new manufacturing methods have been incorporated into the production of the nozzle, the shape, length, and diameter remain the same.

Sixteen main engines remained from the shuttle program. All were modified and tested at NASA Stennis for use on the first four Artemis missions.

posted 06-02-2023 04:38 PM               

NASA Enters Stretch in Critical Moon Rocket Engine Test Series

NASA entered the stretch run of a key RS-25 certification engine test series with a successful hot fire June 1, continuing to set the stage for future Artemis missions to the Moon.

The hot fire on the Fred Haise Test Stand at NASA's Stennis Space Center near Bay St. Louis, Mississippi, marked the ninth in a critical 12 test series. The remaining three tests are scheduled throughout June. The series is designed to certify production of new RS-25 engines by lead contractor Aerojet Rocketdyne for future deep space missions, beginning with Artemis V.

Operators powered the RS-25 engine for more than eight minutes (500 seconds), the same amount of time needed to help launch the SLS (Space Launch System) rocket, carrying astronauts aboard the Orion spacecraft, into orbit. The engine also was fired up to 113% power, exceeding the 111% level needed during launch, to provide engineers with a margin of operational safety.

posted 10-18-2023 01:19 PM               

NASA Conducts First Hot Fire of New RS-25 Certification Test Series

NASA conducted the first hot fire of a new RS-25 test series Oct. 17, beginning the final round of certification testing ahead of production of an updated set of the engines for the SLS (Space Launch System) rocket. The engines will help power future Artemis missions to the Moon and beyond.

Above: NASA completed a full duration, 550-second hot fire of the RS-25 certification engine Oct. 17, beginning a critical test series to support future SLS (Space Launch System) missions. (NASA/Danny Nowlin)

Operators fired the RS-25 engine for more than nine minutes (550 seconds), longer than the 500 seconds engines must fire during an actual mission, on the Fred Haise Test Stand at NASA's Stennis Space Center, near Bay St. Louis, Mississippi. Operators also fired the engine up to the 111% power level needed during an SLS launch. The hot fire marked the first in a series of 12 tests scheduled to stretch into 2024. The tests are a key step for lead SLS engines contractor Aerojet Rocketdyne, an L3Harris Technologies company, to produce engines that will help power the SLS rocket, beginning with Artemis V.

The test series will collect data on the performance of several new key engine components, including a nozzle, hydraulic actuators, flex ducts, and turbopumps. The components match design features of those used during the initial certification test series completed at the south Mississippi site in June. Aerojet Rocketdyne is using advanced manufacturing techniques, such as 3D printing, to reduce the cost and time needed to build the new engines. Four RS-25 engines help power SLS at launch, including on its Artemis missions to the Moon.

posted 04-04-2024 01:52 PM               

NASA Achieves Milestone for Engines to Power Future Artemis Missions

NASA achieved a major milestone April 3 for production of new RS-25 engines to help power its Artemis campaign to the Moon and beyond with completion of a critical engine certification test series at NASA's Stennis Space Center near Bay St. Louis, Mississippi.

The 12-test series represents a key step for lead engines contractor Aerojet Rocketdyne, an L3Harris Technologies company, to build new RS-25 engines, using modern processes and manufacturing techniques, for NASA's SLS (Space Launch System) rockets that will power future lunar missions, beginning with Artemis V.

"The conclusion of the certification test series at NASA Stennis is just the beginning for the next generation of RS-25 engines that will help power human spaceflight for Artemis," said Johnny Heflin, SLS liquid engines manager. "The newly produced engines on future SLS rockets will maintain the high reliability and safe flight operational legacy the RS-25 is known for while enabling more affordable high-performance engines for the next era of deep space exploration."

Through Artemis, NASA will establish the foundation for long-term scientific exploration at the Moon; land the first woman, first person of color, and first international partner astronaut on the lunar surface; and prepare for human expeditions to Mars for the benefit of all.

Contributing to that effort, the NASA Stennis test team conducted a full-duration, 500-second hot fire to complete the 12-test series on developmental engine E0525, providing critical performance data for the final RS-25 design certification review. The April 3 hot fire completed a test series that began in October 2023.

RS-25 engines are evolved space shuttle main engines, upgraded with new components to produce the additional power needed to help launch NASA's SLS rocket. The first four Artemis missions are using modified space shuttle main engines also tested at NASA Stennis. For each Artemis mission, four RS-25 engines, along with a pair of solid rocket boosters, power the SLS rocket, producing more than 8.8 million pounds of total combined thrust at liftoff.

"This was a critical test series, and credit goes to the entire test team for their dedication and unique skills that allowed us to meet the schedule and provide the needed performance data," said Chip Ellis, project manager for RS-25 testing at NASA Stennis. "The tests conducted at NASA Stennis help ensure the safety of our astronauts and their future mission success. We are proud to be part of the Artemis mission."

The E0525 developmental engine featured new key components – including a nozzle, hydraulic actuators, flex ducts, and turbopumps – that matched design features of those used during an initial certification test series completed at NASA Stennis last summer.

The two certification test series helped verify the new engine components meet all Artemis flight requirements moving forward. Aerojet Rocketdyne is using techniques such as 3D printing to produce new RS-25 engines more efficiently, while maintaining high performance and reliability. NASA has awarded the company contracts to provide 24 new engines, supporting SLS launches for Artemis V through Artemis IX.

"Successfully completing this rigorous test series is a testament to the outstanding work done by the team to design, implement and test this upgraded version of the RS-25 that reduces the cost by 30% from the space shuttle program," said Mike Lauer, RS-25 program director at Aerojet Rocketdyne. "We tested the new RS-25 engines to the extreme limits of operation to ensure the engines can operate at a higher power level needed for SLS and complete the mission with margin."