NASA Successfully Test Fires Mars Mega Rocket Engine with Modernized ‘Brain’ Controller

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. The RS-25 will help power the core stage of the agency’s new Space Launch System (SLS) rocket for the journey to Mars.  Credit: Ken Kremer/kenkremer.com
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. The RS-25 will help power the core stage of the agency’s new Space Launch System (SLS) rocket for the journey to Mars. Credit: Ken Kremer/kenkremer.com

NASA STENNIS SPACE CENTER, MISS – NASA engineers successfully carried out a key developmental test firing of an RS-25 rocket engine along with its modernized ‘brain’ controller at the Stennis Space Center on Thursday, Aug. 18, as part of the ongoing huge development effort coordinating the agency’s SLS Mars mega rocket slated for its maiden blastoff by late 2018.

“Today’s test was very successful,” Steve Wofford, manager of the SLS Liquid Engines Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, told Universe Today in an exclusive interview at the conclusion of the exciting RS-25 engine test gushing a huge miles long plume of steam at NASA Stennis on Aug. 18 under sweltering Gulf Coast heat.

“It was absolutely great!”

Thursday’s full thrust RS-25 engine hot fire test, using engine No. 0528, ran for its planned full duration of 7.5 minutes and met a host of critical test objectives required to confirm and scope out the capabilities and operating margins of the upgraded engines ,which are recycled from the shuttle era.

“We ran a full program duration of 420 seconds . And we had no failure identifications pop up.”

“It looks like we achieved all of our data objectives,” Wofford elaborated to Universe Today, after we witnessed the test from a viewing area just a few hundred meters away, with our ears protected by ear plugs.

A cluster of four RS-25 engines will power the Space Launch System (SLS) at the base of the first stage, also known as the core stage.

Huge plume of steam gushes as 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., in this panoramic view.  The RS-25 will help power the core stage of the agency’s new Space Launch System (SLS) rocket for the journey to Mars.  Credit: Ken Kremer/kenkremer.com
Huge plume of steam gushes as 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., in this panoramic view. The RS-25 will help power the core stage of the agency’s new Space Launch System (SLS) rocket for the journey to Mars. Credit: Ken Kremer/kenkremer.com

SLS is the most powerful booster the world has even seen and one day soon will propel NASA astronauts in the agency’s Orion crew capsule on exciting missions of exploration to deep space destinations including the Moon, Asteroids and Mars – venturing further out than humans ever have before!

NASA’s goal is to send humans to Mars by the 2030s with SLS and Orion.

Ignition of the RS-25 engine creates a huge plume of steam gushing out the test stand during successful  hot fire development test on Thursday, Aug. 18 at NASA’s Stennis Space Center near Bay St. Louis, Miss., in this panoramic view.  The RS-25 will help power the core stage of the agency’s new Space Launch System (SLS) rocket for the journey to Mars.  Credit: Ken Kremer/kenkremer.com
Ignition of the RS-25 engine creates a huge plume of steam gushing out the test stand during successful hot fire development test on Thursday, Aug. 18 at NASA’s Stennis Space Center near Bay St. Louis, Miss., in this panoramic view. The RS-25 will help power the core stage of the agency’s new Space Launch System (SLS) rocket for the journey to Mars. Credit: Ken Kremer/kenkremer.com

The primary goal of the development tests is to validate the capabilities of a new controller – or, “brain” – for the engine and to verify the different operating conditions needed for the SLS vehicle.

The test was part of a long continuing and new series aimed at certifying the engines for flight.

“We continue this test series in the fall. Which is a continuing part of our certification series to fly these engines on NASA’s SLS vehicle,” Wofford told me.

What was the primary objective of today’s test?

“Today’s test was mostly about wringing out the new control system. We have a new engine controller on this engine. And we have to certify that new controller for flight.”

“So to certify it we run it through its paces in ground tests. And we put it through a more stringent set of test conditions than it will ever see in flight.”

“The objectives we tested today required 420 seconds of testing to complete.”

Watch this NASA video of the full test:

Video Caption: RS-25 Rocket Engine Test Firing on 18 Aug. 2016: The 7.5-minute test conducted at NASA’s Stennis Space Center is part of a series of tests designed to put the upgraded former space shuttle engines through the rigorous temperature and pressure conditions they will experience during a launch of NASA’s Space Launch System mega rocket. Credit: NASA

What are the additional objectives from today’s test?

“Well you can’t do all of your objectives in one test. So the certification series are all about technical objectives and total accumulated time. So one thing we did was we accumulated time toward the time we need to certify this control system for the SLS engine,” Wofford explained.

“The other thing we did was you pick some technical objectives you want to put the controller through its paces for. And again you can’t do all of those in one test. So you spread them over a series. And we did some of those on this test.”

Aerojet Rocketdyne is the prime contractor for the RS-25 engine work and originally built them during the shuttle era.

The remaining cache of 16 heritage RS-25 engines are being recycled from their previous use as reusable space shuttle main engines (SSMEs). They are now being refurbished, upgraded and tested by NASA and Aerojet Rocketdyne to power the core stage of the Space Launch System rocket now under full development.

During launch they will fire at 109 percent thrust level for some eight and a half minutes while generating a combined two million pounds of thrust.

The SLS core stage is augmented with a pair of five segment solid rocket boosters (SRBs) generating about 3.3 million pounds of thrust each. NASA and Orbital just completed the QM-2 SRB qualification test on June 28.

Each of the RS-25’s engines generates some 500,000 pounds of thrust. They are fueled by cryogenic liquid hydrogen (LH2) and liquid oxygen (LOX).

The first liquid hydrogen (LH2) qualification fuel tank for the core stage was just welded together at NASA’s Michoud Assembly Facility in New Orleans – as I witnessed exclusively and reported here.

The first liquid hydrogen tank, also called the qualification test article, for NASA's new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine on July 22, 2016 after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans.  Credit: Ken Kremer/kenkremer.com
The first liquid hydrogen tank, also called the qualification test article, for NASA’s new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine on July 22, 2016 after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com

The RS-25 engines measure 14 feet tall and 8 feet in diameter.

For SLS they will be operating at 109% of power – a higher power level compared to a routine usage of 104.5% during the shuttle era.

They have to withstand and survive temperature extremes ranging from -423 degrees F to more than 6000 degrees F.

Why was about five seconds of Thursday’s test run at the 111% power level? Will that continue in future tests?

“We did that because we plan to fly this engine on SLS at 109% of power level. So it’s to demonstrate the feasibility of doing that. On shuttle we were certified to fly these engines at 109%,” Wofford confirmed to Universe Today.

“So to demonstrate the feasibility of doing 109% power level on SLS we ‘overtest’ . So we ran [today’s test] at 2 % above where we are going to fly in flight.”

“We will do more in the future.”

The fully assembled core stage intergrated with all 4 RS-25 flight engines will be tested at the B-2 test stand in Stennis during the first quarter of 2018 – some 6 months or more before the launch in late 2018.

How many more engines tests will be conducted prior to the core stage test?

“After today we will run 7 more tests before the core stage test and the first flight.”

“I’m thrilled. I’ve see a lot of these and it never gets old!” Wofford gushed.

The hardware for SLS and Orion is really coming together now and its becoming more and more real every day.

Orion crew module pressure vessel for NASA’s Exploration Mission-1 (EM-1) is unveiled for the first time on Feb. 3, 2016 after arrival at the agency’s Kennedy Space Center (KSC) in Florida. It is secured for processing in a test stand called the birdcage in the high bay inside the Neil Armstrong Operations and Checkout (O&C) Building at KSC. Launch to the Moon is slated in 2018 atop the SLS rocket.  Credit: Ken Kremer/kenkremer.com
Orion crew module pressure vessel for NASA’s Exploration Mission-1 (EM-1) is unveiled for the first time on Feb. 3, 2016 after arrival at the agency’s Kennedy Space Center (KSC) in Florida. It is secured for processing in a test stand called the birdcage in the high bay inside the Neil Armstrong Operations and Checkout (O&C) Building at KSC. Launch to the Moon is slated in 2018 atop the SLS rocket. Credit: Ken Kremer/kenkremer.com

These are exciting times for NASA’s human deep space exploration strategy.

The maiden test flight of the SLS/Orion is targeted for no later than November 2018 and will be configured in its initial 70-metric-ton (77-ton) Block 1 configuration with a liftoff thrust of 8.4 million pounds – more powerful than NASA’s Saturn V moon landing rocket.

Although the SLS-1 flight in 2018 will be uncrewed, NASA plans to launch astronauts on the SLS-2/EM-2 mission slated for the 2021 to 2023 timeframe.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

Steve Wofford, manager of the SLS Liquid Engines Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, interviewed by Ken Kremer, Universe Today about the RS-25 hot fire engine test on Aug. 18 at NASA’s Stennis Space Center near Bay St. Louis, Miss.  The RS-25 will help power NASA’s Space Launch System (SLS) rocket.  Credit: Ken Kremer/kenkremer.com
Steve Wofford, manager of the SLS Liquid Engines Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, interviewed by Ken Kremer, Universe Today about the RS-25 hot fire engine test on Aug. 18 at NASA’s Stennis Space Center near Bay St. Louis, Miss. The RS-25 will help power NASA’s Space Launch System (SLS) rocket. Credit: Ken Kremer/kenkremer.com

NASA Welds Together 1st SLS Hydrogen Test Tank for America’s Moon/Mars Rocket – Flight Unit in Progress

The first liquid hydrogen tank, also called the qualification test article, on NASA's new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine on July 22, 2016 after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans.  Credit: Ken Kremer/kenkremer.com
The first liquid hydrogen tank, also called the qualification test article, for NASA’s new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine on July 22, 2016 after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com

MICHOUD ASSEMBLY FACILITY, NEW ORLEANS, LA – NASA has just finished welding together the very first fuel tank for America’s humongous Space Launch System (SLS) deep space rocket currently under development – and Universe Today had an exclusive up close look at the liquid hydrogen (LH2) test tank shortly after its birth as well as the first flight tank, during a tour of NASA’s New Orleans rocket manufacturing facility on Friday, July 22, shortly after completion of the milestone assembly operation.

“We have just finished welding the first liquid hydrogen qualification tank article …. and are in the middle of production welding of the first liquid hydrogen flight hardware tank [for SLS-1] in the big Vertical Assembly Center welder!” explained Patrick Whipps, NASA SLS Stages Element Manager, in an exclusive hardware tour and interview with Universe Today on July 22, 2016 at NASA’s Michoud Assembly Facility (MAF) in New Orleans.

“We are literally putting the SLS rocket hardware together here at last. All five elements to put the SLS stages together [at Michoud].”

This first fully welded SLS liquid hydrogen tank is known as a ‘qualification test article’ and it was assembled using basically the same components and processing procedures as an actual flight tank, says Whipps.

“We just completed the liquid hydrogen qualification tank article and lifted it out of the welding machine and put it into some cradles. We will put it into a newly designed straddle carrier article next week to transport it around safely and reliably for further work.”

And welding of the liquid hydrogen flight tank is moving along well.

“We will be complete with all SLS core stage flight tank welding in the VAC by the end of September,” added Jackie Nesselroad, SLS Boeing manager at Michoud. “It’s coming up very quickly!”

“The welding of the forward dome to barrel 1 on the liquid hydrogen flight tank is complete. And we are doing phased array ultrasonic testing right now!”

SLS is the most powerful booster the world has even seen and one day soon will propel NASA astronauts in the agency’s Orion crew capsule on exciting missions of exploration to deep space destinations including the Moon, Asteroids and Mars – venturing further out than humans ever have before!

The LH2 ‘qualification test article’ was welded together using the world’s largest welder – known as the Vertical Assembly Center, or VAC, at Michoud.

And it’s a giant! – measuring approximately 130-feet in length and 27.6 feet (8.4 m) in diameter.

See my exclusive up close photos herein documenting the newly completed tank as the first media to visit the first SLS tank. I saw the big tank shortly after it was carefully lifted out of the welder and placed horizontally on a storage cradle on Michoud’s factory floor.

The newly assembled first liquid hydrogen tank, also called the qualification test article, for NASA's new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine (blue) on July 22, 2016. It was lifted out of the welder (top) after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans.  Credit: Ken Kremer/kenkremer.com
The newly assembled first liquid hydrogen tank, also called the qualification test article, for NASA’s new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine (blue) on July 22, 2016. It was lifted out of the welder (top) after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com

Finishing its assembly after years of meticulous planning and hard work paves the path to enabling the maiden test launch of the SLS heavy lifter in the fall of 2018 from the Kennedy Space Center (KSC) in Florida.

The qual test article is the immediate precursor to the actual first LH2 flight tank now being welded.

“We will finish welding the liquid hydrogen and liquid oxygen flight tanks by September,” Whipps told Universe Today.

Up close view of the dome of the newly assembled first ever liquid hydrogen test tank for NASA's new Space Launch System (SLS) heavy lift rocket on July 22, 2016  after it was welded together at NASA’s Michoud Assembly Facility in New Orleans.  Sensors will be attached to both ends for upcoming structural loads and proof testing.  Credit: Ken Kremer/kenkremer.com
Up close view of the dome of the newly assembled first ever liquid hydrogen test tank for NASA’s new Space Launch System (SLS) heavy lift rocket on July 22, 2016 after it was welded together at NASA’s Michoud Assembly Facility in New Orleans. Sensors will be attached to both ends for upcoming structural loads and proof testing. Credit: Ken Kremer/kenkremer.com

Technicians assembled the LH2 tank by feeding the individual metallic components into NASA’s gigantic “Welding Wonder” machine – as its affectionately known – at Michoud, thus creating a rigid 13 story tall structure.

The welding work was just completed this past week on the massive silver colored structure. It was removed from the VAC welder and placed horizontally on a cradle.

I watched along as the team was also already hard at work fabricating SLS’s first liquid hydrogen flight article tank in the VAC, right beside the qualification tank resting on the floor.

Welding of the other big fuel tank, the liquid oxygen (LOX) qualification and flight article tanks will follow quickly inside the impressive ‘Welding Wonder’ machine, Nesselroad explained.

The LH2 and LOX tanks sit on top of one another inside the SLS outer skin.

The SLS core stage – or first stage – is mostly comprised of the liquid hydrogen and liquid oxygen cryogenic fuel storage tanks which store the rocket propellants at super chilled temperatures. Boeing is the prime contractor for the SLS core stage.

To prove that the new welding machines would work as designed, NASA opted “for a 3 stage assembly philosophy,” Whipps explained.

Engineers first “welded confidence articles for each of the tank sections” to prove out the welding techniques “and establish a learning curve for the team and test out the software and new weld tools. We learned a lot from the weld confidence articles!”

“On the heels of that followed the qualification weld articles” for tank loads testing.

“The qualification articles are as ‘flight-like’ as we can get them! With the expectation that there are still some tweaks coming.”

“And finally that leads into our flight hardware production welding and manufacturing the actual flight unit tanks for launches.”

“All the confidence articles and the LH2 qualification article are complete!”

What’s the next step for the LH2 tank?

The test article tank will be outfitted with special sensors and simulators attached to each end to record reams of important engineering data, thereby extending it to about 185 feet in length.

Thereafter it will loaded onto the Pegasus barge and shipped to NASA’s Marshall Space Flight Center in Huntsville, Alabama, for structural loads testing on one of two new test stands currently under construction for the tanks. The tests are done to prove that the tanks can withstand the extreme stresses of spaceflight and safely carry our astronauts to space.

“We are manufacturing the simulators for each of the SLS elements now for destructive tests – for shipment to Marshall. It will test all the stress modes, and finally to failure to see the process margins.”

NASA’s Space Launch System (SLS) blasts off from launch pad 39B at the Kennedy Space Center in this artist rendering showing a view of the liftoff of the Block 1 70-metric-ton (77-ton) crew vehicle configuration.   Credit: NASA/MSFC
NASA’s Space Launch System (SLS) blasts off from launch pad 39B at the Kennedy Space Center in this artist rendering showing a view of the liftoff of the Block 1 70-metric-ton (77-ton) crew vehicle configuration. Credit: NASA/MSFC

The SLS core stage builds on heritage from NASA’s Space Shuttle Program and is based on the shuttle’s External Tank (ET). All 135 ET flight units were built at Michoud during the thirty year long shuttle program by Lockheed Martin.

“We saved billions of dollars and years of development effort vs. starting from a clean sheet of paper design, by taking aspects of the shuttle … and created an External Tank type generic structure – with the forward avionics on top and the complex engine section with 4 engines (vs. 3 for shuttle) on the bottom,” Whipps elaborated.

“This is truly an engineering marvel like the External Tank was – with its strength that it had and carrying the weight that it did. If you made our ET the equivalent of a Coke can, our thickness was about 1/5 of a coke can.”

“It’s a tremendous engineering job. But the ullage pressures in the LOX and LH2 tanks are significantly more and the systems running down the side of the SLS tank are much more sophisticated. Its all significantly more complex with the feed lines than what we did for the ET. But we brought forward the aspects and designs that let us save time and money and we knew were effective and reliable.”

The Vertical Weld Center tool used to fabricate barrel segments for the SLS liquid hydrogen and oxygen core stage tanks via vertical friction stir welding operations at NASA’s Michoud Assembly Facility in New Orleans.  Credit: Ken Kremer/kenkremer.com
The Vertical Weld Center tool used to fabricate barrel segments for the SLS liquid hydrogen and oxygen core stage tanks via vertical friction stir welding operations at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com

The SLS core stage is comprised of five major structures: the forward skirt, the liquid oxygen tank (LOX), the intertank, the liquid hydrogen tank (LH2) and the engine section.

The LH2 and LOX tanks feed the cryogenic propellants into the first stage engine propulsion section which is powered by a quartet of RS-25 engines – modified space shuttle main engines (SSMEs) – and a pair of enhanced five segment solid rocket boosters (SRBs) also derived from the shuttles four segment boosters.

The tanks are assembled by joining previously manufactured dome, ring and barrel components together in the Vertical Assembly Center by a process known as friction stir welding. The rings connect and provide stiffness between the domes and barrels.

The LH2 tank is the largest major part of the SLS core stage. It holds 537,000 gallons of super chilled liquid hydrogen. It is comprised of 5 barrels, 2 domes, and 2 rings.

The LOX tank holds 196,000 pounds of liquid oxygen. It is assembled from 2 barrels, 2 domes, and 2 rings and measures over 50 feet long.

The material of construction of the tanks has changed compared to the ET.

“The tanks are constructed of a material called the Aluminum 2219 alloy,” said Whipps. “It’s a ubiquosly used aerospace alloy with some copper but no lithium, unlike the shuttle superlightweight ET tanks that used Aluminum 2195. The 2219 has been a success story for the welding. This alloy is heavier but does not affect our payload potential.”

“The intertanks are the only non welded structure. They are bolted together and we are manufacturing them also. It’s much heavier and thicker.”

Overall, the SLS core stage towers over 212 feet (64.6 meters) tall and sports a diameter of 27.6 feet (8.4 m).

NASA’s Vehicle Assembly Center is the world’s largest robotic weld tool. The domes and barrels are assembled from smaller panels and piece parts using other dedicated robotic welding machines at Michoud.

The total weight of the whole core stage empty is 188,000 pounds and 2.3 million pounds when fully loaded with propellant. The empty ET weighed some 55,000 pounds.

Considering that the entire Shuttle ET was 154-feet long, the 130-foot long LH2 tank alone isn’t much smaller and gives perspective on just how big it really is as the largest rocket fuel tank ever built.

“So far all the parts of the SLS rocket are coming along well.”

“The Michoud SLS workforce totals about 1000 to 1500 people between NASA and the contractors.”

Every fuel tank welded together from now on after this series of confidence and qualification LOX and LH2 tanks will be actual flight article tanks for SLS launches.

“There are no plans to weld another qualification tank after this,” Nesselroad confirmed to me.

What’s ahead for the SLS-2 core stage?

“We start building the second SLS flight tanks in October of this year – 2016!” Nesselroad stated.

The world’s largest welder was specifically designed to manufacture the core stage of the world’s most powerful rocket – NASA’s SLS.

The Vertical Assembly Center welder was officially opened for business at NASA’s Michoud Assembly Facility in New Orleans on Friday, Sept. 12, 2014.

NASA Administrator Charles Bolden was personally on hand for the ribbon-cutting ceremony at the base of the huge VAC welder.

The state-of-the-art welding giant stands 170 feet tall and 78 feet wide. It complements the world-class welding toolkit being used to assemble various pieces of the SLS core stage including the domes, rings and barrels that have been previously manufactured.

The Gore Weld Tool (foreground) and  Circumferential Dome Weld Tool (background) Center tool used to fabricate dome segments for the SLS liquid hydrogen and oxygen core stage tanks via vertical friction stir welding operations at NASA’s Michoud Assembly Facility in New Orleans.  Credit: Ken Kremer/kenkremer.com
The Gore Weld Tool (foreground) and Circumferential Dome Weld Tool (background) used to fabricate dome segments for the SLS liquid hydrogen and oxygen core stage tanks via vertical friction stir welding operations at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com

The maiden test flight of the SLS/Orion is targeted for no later than November 2018 and will be configured in its initial 70-metric-ton (77-ton) Block 1 configuration with a liftoff thrust of 8.4 million pounds – more powerful than NASA’s Saturn V moon landing rocket.

Although the SLS-1 flight in 2018 will be uncrewed, NASA plans to launch astronauts on the SLS-2/EM-2 mission slated for the 2021 to 2023 timeframe.

The exact launch dates fully depend on the budget NASA receives from Congress and who is elected President in the November 2016 election – and whether they maintain or modify NASA’s objectives.

“If we can keep our focus and keep delivering, and deliver to the schedules, the budgets and the promise of what we’ve got, I think we’ve got a very capable vision that actually moves the nation very far forward in moving human presence into space,” said William Gerstenmaier, associate administrator for the Human Exploration and Operations Mission Directorate at NASA Headquarters in Washington, during the post QM-2 SRB test media briefing in Utah last month.

“This is a very capable system. It’s not built for just one or two flights. It is actually built for multiple decades of use that will enable us to eventually allow humans to go to Mars in the 2030s.”

Orion crew module pressure vessel for NASA’s Exploration Mission-1 (EM-1) is unveiled for the first time on Feb. 3, 2016 after arrival at the agency’s Kennedy Space Center (KSC) in Florida. It is secured for processing in a test stand called the birdcage in the high bay inside the Neil Armstrong Operations and Checkout (O&C) Building at KSC. Launch to the Moon is slated in 2018 atop the SLS rocket.  Credit: Ken Kremer/kenkremer.com
Orion crew module pressure vessel for NASA’s Exploration Mission-1 (EM-1) is unveiled for the first time on Feb. 3, 2016 after arrival at the agency’s Kennedy Space Center (KSC) in Florida. It is secured for processing in a test stand called the birdcage in the high bay inside the Neil Armstrong Operations and Checkout (O&C) Building at KSC. Launch to the Moon is slated in 2018 atop the SLS rocket. Credit: Ken Kremer/kenkremer.com

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

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Learn more about SLS and Orion crew vehicle, SpaceX CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Juno at Jupiter, Orbital ATK Antares & Cygnus, Boeing, Space Taxis, Mars rovers, NASA missions and more at Ken’s upcoming outreach events:

July 27-28: “ULA Atlas V NRO Spysat launch July 28, SpaceX launch to ISS on CRS-9, SLS, Orion, Juno at Jupiter, ULA Delta 4 Heavy NRO spy satellite, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

Graphic shows all the dome, barrel, ring and engine components used to assemble the five major structures of the core stage of NASA’s Space Launch System (SLS) in Block 1 configuration. Credits: NASA/MSFC
Graphic shows all the dome, barrel, ring and engine components used to assemble the five major structures of the core stage of NASA’s Space Launch System (SLS) in Block 1 configuration. Credits: NASA/MSFC
At NASA’s Michoud Assembly Facility in New Orleans, Patrick Whipps/NASA SLS Stages Element Manager and Ken Kremer/Universe Today discuss details of SLS manufacture by the Circumferential Dome Weld Tool used to fabricate dome segments for the SLS liquid hydrogen and oxygen core stage tanks.   Credit: Ken Kremer/kenkremer.com
At NASA’s Michoud Assembly Facility in New Orleans, Patrick Whipps/NASA SLS Stages Element Manager and Ken Kremer/Universe Today discuss details of SLS manufacture by the Circumferential Dome Weld Tool used to fabricate dome segments for the SLS liquid hydrogen and oxygen core stage tanks. Credit: Ken Kremer/kenkremer.com
Graphic shows Block I configuration of NASA’s Space Launch System (SLS). Credits: NASA/MSFC
Graphic shows Block I configuration of NASA’s Space Launch System (SLS). Credits: NASA/MSFC

NASA Test Fires SLS Flight Engine Destined to Launch Astronauts Back to the Moon

NASA engineers conduct a successfully test firing of RS-25 rocket engine No. 2059 on the A-1 Test Stand at NASA’s Stennis Space Center in Bay St. Louis, Mississippi. The hot fire marks the first test of an RS-25 flight engine for NASA’s new Space Launch System vehicle.  Credits: NASA/SSC
NASA engineers conduct a successful test firing of RS-25 rocket engine No. 2059 on the A-1 Test Stand at NASA’s Stennis Space Center in Bay St. Louis, Mississippi. The hot fire marks the first test of an RS-25 flight engine for NASA’s new Space Launch System vehicle. Credits: NASA/SSC

NASA engineers have successfully test fired the first flight engine destined to power the agency’s mammoth new SLS rocket that will launch American astronauts back to the Moon and deep space for the first time in nearly five decades.

The flight proven RS-25 powerplant engine previously flew as one of three main engines that successfully rocketed NASA’s space shuttle orbiters to space during the three decade long Space Shuttle era that ended in 2011. Continue reading “NASA Test Fires SLS Flight Engine Destined to Launch Astronauts Back to the Moon”

NASA Awards Contract to Aerojet Rocketdyne to Restart RS-25 Engine Production for SLS Mars Rocket

NASA took another big step on the path to propel our astronauts back to deep space and ultimately on to Mars with the long awaited decision to formally restart production of the venerable RS-25 engine that will power the first stage of the agency’s mammoth Space Launch System (SLS) heavy lift rocket, currently under development.

Aerojet Rocketdyne was awarded a NASA contract to reopen the production lines for the RS-25 powerplant and develop and manufacture a certified engine for use in NASA’s SLS rocket. The contract spans from November 2015 through Sept. 30, 2024.

The SLS is the most powerful rocket the world has ever seen and will loft astronauts in the Orion capsule on missions back to the Moon by around 2021, to an asteroid around 2025 and then beyond on a ‘Journey to Mars’ in the 2030s – NASA’s overriding and agency wide goal. The first unmanned SLS test flight is slated for late 2018.

The core stage (first stage) of the SLS will initially be powered by four existing RS-25 engines, recycled and upgraded from the shuttle era, and a pair of five-segment solid rocket boosters that will generate a combined 8.4 million pounds of liftoff thrust, making it the world’s most powerful rocket ever.

The newly awarded RS-25 engine contract to Sacramento, California based Aerojet Rocketdyne is valued at 1.16 Billion and aims to “modernize the space shuttle heritage engine to make it more affordable and expendable for SLS,” NASA announced on Nov. 23. NASA can also procure up to six new flight worthy engines for later launches.

“SLS is America’s next generation heavy lift system,” said Julie Van Kleeck, vice president of Advanced Space & Launch Programs at Aerojet Rocketdyne, in a statement.

“This is the rocket that will enable humans to leave low Earth orbit and travel deeper into the solar system, eventually taking humans to Mars.”

The lead time is approximately 5 or 6 years to build and certify the first new RS-25 engine, Van Kleek told Universe Today in an interview. Therefore NASA needed to award the contract to Aerojet Rocketdyne now so that its ready when needed.

NASA’s Space Launch System (SLS) blasts off from launch pad 39B at the Kennedy Space Center in this artist rendering showing a view of the liftoff of the Block 1 70-metric-ton (77-ton) crew vehicle configuration.   Credit: NASA/MSFC
NASA’s Space Launch System (SLS) blasts off from launch pad 39B at the Kennedy Space Center in this artist rendering showing a view of the liftoff of the Block 1 70-metric-ton (77-ton) crew vehicle configuration. Credit: NASA/MSFC

The RS-25 is actually an upgraded version of former space shuttle main engines (SSMEs) originally built by Aerojet Rocketdyne.

The reusable engines were used with a 100% success rate during NASA’s three decade-long Space Shuttle program to propel the now retired shuttle orbiters to low Earth orbit.

Atlantis rolls over  from the Orbiter Processing Facility (OPF-1, at right)  processing hanger to the Vehicle Assembly Building (VAB, at left) at KSC for the STS-135 mission.  Credit: Ken Kremer
Space Shuttles were powered by a trio of Space Shuttle Main Engines (SSMEs) now recycled and upgraded as RS-25 engines for SLS. Atlantis rolls over from the Orbiter Processing Facility (OPF-1, at right) processing hanger to the Vehicle Assembly Building (VAB, at left) at KSC for the STS-135 mission. Credit: Ken Kremer

Those same engines are now being modified for use by the SLS on missions to deep space starting in 2018.

But NASA only has an inventory of 16 of the RS-25 engines, which is sufficient for a maximum of the first four SLS launches only. Although they were reused numerous times during the shuttle era, they will be discarded after each SLS launch.

During a 535-second test on August 13, 2015, operators ran the Space Launch System (SLS) RS-25 rocket engine through a series of tests at different power levels to collect engine performance data on the A-1 test stand at NASA's Stennis Space Center near Bay St. Louis, Mississippi.  Credit: NASA
During a 535-second test on August 13, 2015, operators ran the Space Launch System (SLS) RS-25 rocket engine through a series of tests at different power levels to collect engine performance data on the A-1 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. Credit: NASA

And since the engines cannot be recovered and reused as during the shuttle era, a brand new set of RS-25s will have to be manufactured from scratch.

Therefore, the engine manufacturing process can and will be modernized and significantly streamlined – using fewer part and welds – to cut costs and improve performance.

“The RS-25 engines designed under this new contract will be expendable with significant affordability improvements over previous versions,” added Jim Paulsen, vice president, Program Execution, Advanced Space & Launch Programs at Aerojet Rocketdyne. “This is due to the incorporation of new technologies, such as the introduction of simplified designs; 3-D printing technology called additive manufacturing; and streamlined manufacturing in a modern, state-of-the-art fabrication facility.”

“The new engines will incorporate simplified, yet highly reliable, designs to reduce manufacturing time and cost. For example, the overall engine is expected to simplify key components with dramatically reduced part count and number of welds. At the same time, the engine is being certified to a higher operational thrust level,” says Aerojet Rocketdyne.

The existing stock of 16 RS-25s are being upgraded for use in SLS and also being run through a grueling series of full duration hot fire test firings to certify them for flight, as I reported previously here at Universe Today.

Among the RS-25 upgrades is a new engine controller specific to SLS. The engine controller functions as the “brain” of the engine, which checks engine status, maintains communication between the vehicle and the engine and relays commands back and forth.

RS-25 test firing in progress on the A-1 test stand at NASA's Stennis Space Center near Bay St. Louis, Mississippi, on Aug. 13, 2015.  Credit: NASA
RS-25 test firing in progress on the A-1 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi, on Aug. 13, 2015. Credit: NASA

Each of the RS-25’s engines generates some 500,000 pounds of thrust. They are fueled by cryogenic liquid hydrogen and liquid oxygen. For SLS they will be operating at 109% of power, compared to a routine usage of 104.5% during the shuttle era. They measure 14 feet tall and 8 feet in diameter.

They have to withstand and survive temperature extremes ranging from -423 degrees F to more than 6000 degrees F.

The maiden test flight of the SLS is targeted for no later than November 2018 and will be configured in its initial 70-metric-ton (77-ton) version with a liftoff thrust of 8.4 million pounds. It will boost an unmanned Orion on an approximately three week long test flight beyond the Moon and back.

NASA plans to gradually upgrade the SLS to achieve an unprecedented lift capability of 130 metric tons (143 tons), enabling the more distant missions even farther into our solar system.

The first SLS test flight with the uncrewed Orion is called Exploration Mission-1 (EM-1) and will launch from Launch Complex 39-B at the Kennedy Space Center.

Orion’s inaugural mission dubbed Exploration Flight Test-1 (EFT) was successfully launched on a flawless flight on Dec. 5, 2014 atop a United Launch Alliance Delta IV Heavy rocket Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

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Learn more about SLS, Orion, SpaceX, Orbital ATK Cygnus, ISS, ULA Atlas rocket, Boeing, Space Taxis, Mars rovers, Antares, NASA missions and more at Ken’s upcoming outreach events:

Dec 1 to 3: “Orbital ATK Atlas/Cygnus launch to the ISS, ULA, SpaceX, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

Dec 8: “America’s Human Path Back to Space and Mars with Orion, Starliner and Dragon.” Amateur Astronomers Assoc of Princeton, AAAP, Princeton University, Ivy Lane, Astrophysics Dept, Princeton, NJ; 7:30 PM.

Milestone Test Firing of NASA’s SLS Monster Rocket Engine Advances Human Path to Deep Space

During a 535-second test on August 13, 2015, operators ran the Space Launch System (SLS) RS-25 rocket engine through a series of tests at different power levels to collect engine performance data on the A-1 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. Credit: NASA
Story/imagery updated
See video below of full duration hot-fire test
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With today’s (Aug. 13) successful test firing of an RS-25 main stage engine for NASA’s Space Launch System (SLS) monster rocket currently under development, the program passed a key milestone advancing the agency on the path to propel astronauts back to deep space at the turn of the decade.

The 535 second long test firing of the RS-25 development engine was conducted on the A-1 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi – and ran for the planned full duration of nearly 9 minutes, matching the time they will fire during an actual SLS launch.

All indications are that the hot fire test apparently went off without a hitch, on first look.

“We ran the full duration and met all test objectives,” said Steve Wofford, SLS engine manager, on NASA TV following today’s’ test firing.

“There were no anomalies.” – based on the initial look.

The RS-25 is actually an upgraded version of former space shuttle main engines that were used with a 100% success rate during NASA’s three decade-long Space Shuttle program to propel the now retired shuttle orbiters to low Earth orbit. Those same engines are now being modified for use by the SLS.

Spectators enjoy the view during the Aug. 13, 2015 test firing of the RS-25 engine for NASA’s Space Launch System (SLS) on the A-1 test stand at NASA's Stennis Space Center near Bay St. Louis, Mississippi.  Credit: NASA
Spectators enjoy the view during the Aug. 13, 2015 test firing of the RS-25 engine for NASA’s Space Launch System (SLS) on the A-1 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. Credit: NASA

“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,” according to NASA officials .

The engine controller functions as the “brain” of the engine, which checks engine status, maintains communication between the vehicle and the engine and relays commands back and forth.

The core stage (first stage) of the SLS will be powered by four RS-25 engines and a pair of the five-segment solid rocket boosters that will generate a combined 8.4 million pounds of liftoff thrust, making it the most powerful rocket the world has ever seen.

Since shuttle orbiters were equipped with three space shuttle main engines, the use of four RS-25s on the SLS represents another significant change that also required many modifications being thoroughly evaluated as well.

RS-25 test firing in progress on the A-1 test stand at NASA's Stennis Space Center near Bay St. Louis, Mississippi, on Aug. 13, 2015.  Credit: NASA
RS-25 test firing in progress on the A-1 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi, on Aug. 13, 2015. Credit: NASA

The SLS will be some 10 percent more powerful than the Saturn V rockets that propelled astronauts to the Moon, including Neil Armstrong, the human to walk on the Moon during Apollo 11 in July 1969.

SLS will loft astronauts in the Orion capsule on missions back to the Moon by around 2021, to an asteroid around 2025 and then beyond on a ‘Journey to Mars’ in the 2030s – NASA’s overriding and agency wide goal.

Each of the RS-25’s engines generates some 500,000 pounds of thrust. They are fueled by cryogenic liquid hydrogen and liquid oxygen. For SLS they will be operating at 109% of power, compared to a routine usage of 104.5% during the shuttle era. They measure 14 feet tall and 8 feet in diameter.

They have to withstand and survive temperature extremes ranging from -423 degrees F to more than 6000 degrees F.

This video shows the full duration hot-fire test:

NASA has 16 of the RS-25s leftover from the shuttle era and they are all being modified and upgraded for use by the SLS rocket.

Today’s test was the sixth in a series of seven to qualify the modified engines to flight status. The engine ignited at 5:01 p.m. EDT and reached the full thrust level of 512,000 pounds within about 5 seconds.

The hot gas was exhausted out of the nozzle at 13 times the speed of sound.

Since the shuttle engines were designed and built over three decades ago, they are being modified where possible with state of the art components to enhance performance, functionality and ease of operation, by prime contractor Aerojet-Rocketdyne of Sacramento, California.

One of the key objectives of today’s engine firing and the entire hot fire series was to test the performance of a brand new engine controller assembled with modern manufacturing techniques.

“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,” says NASA.

“The new controller, or “brain,” for the engine, which monitors engine status and communicates 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.’

Video caption: RS-25 – The Ferrari of Rocket Engines explained. Credit: NASA

“The RS-25 is the most complicated rocket engine out there on the market, but that’s because it’s the Ferrari of rocket engines,” says Kathryn Crowe, RS-25 propulsion engineer.

“When you’re looking at designing a rocket engine, there are several different ways you can optimize it. You can optimize it through increasing its thrust, increasing the weight to thrust ratio, or increasing its overall efficiency and how it consumes your propellant. With this engine, they maximized all three.”

Engineers will now pour over the data collected from hundreds of data channels in great detail to thoroughly analyze the test results. They will incorporate any findings into future test firings of the RS-25s.

NASA says that testing of RS-25 flight engines is set to start later this fall.

“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.”

NASA plans to buy completely new sets of RS-25 engines from Aerojet-Rocketdyne taking full advantage of technological advances and modern manufacturing techniques as well as lessons learned from this hot fire series of engine tests.

The maiden test flight of the SLS is targeted for no later than November 2018 and will be configured in its initial 70-metric-ton (77-ton) version with a liftoff thrust of 8.4 million pounds. It will boost an unmanned Orion on an approximately three week long test flight beyond the Moon and back.

Artist concept of the SLS Block 1 configuration.  Credit: NASA
Artist concept of the SLS Block 1 configuration. Credit: NASA

NASA plans to gradually upgrade the SLS to achieve an unprecedented lift capability of 130 metric tons (143 tons), enabling the more distant missions even farther into our solar system.

The first SLS test flight with the uncrewed Orion is called Exploration Mission-1 (EM-1) and will launch from Launch Complex 39-B at the Kennedy Space Center.

NASA’s first Orion spacecraft blasts off at 7:05 a.m. atop United Launch Alliance Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida on Dec. 5, 2014.   Credit: Ken Kremer - kenkremer.com
NASA’s first Orion spacecraft blasts off at 7:05 a.m. atop United Launch Alliance Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida on Dec. 5, 2014. Credit: Ken Kremer – kenkremer.com

Orion’s inaugural mission dubbed Exploration Flight Test-1 (EFT) was successfully launched on a flawless flight on Dec. 5, 2014 atop a United Launch Alliance Delta IV Heavy rocket Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

NASA Administrator Charles Bolden officially unveils world’s largest welder to start construction of core stage of NASA's Space Launch System (SLS) rocket at NASA Michoud Assembly Facility, New Orleans, on Sept. 12, 2014. SLS will be the world’s most powerful rocket ever built.  Credit: Ken Kremer - kenkremer.com
NASA Administrator Charles Bolden officially unveils world’s largest welder to start construction of core stage of NASA’s Space Launch System (SLS) rocket at NASA Michoud Assembly Facility, New Orleans, on Sept. 12, 2014. SLS will be the world’s most powerful rocket ever built. Credit: Ken Kremer – kenkremer.com
STS-135: Last launch using RS-25 engines that will now power NASA’s SLS deep space exploration rocket. NASA’s 135th and final shuttle mission takes flight on July 8, 2011 at 11:29 a.m. from the Kennedy Space Center in Florida bound for the ISS and the high frontier with Chris Ferguson as Space Shuttle Commander. Credit: Ken Kremer/kenkremer.com
STS-135: Last launch using RS-25 engines that will now power NASA’s SLS deep space exploration rocket. NASA’s 135th and final shuttle mission takes flight on July 8, 2011 at 11:29 a.m. from the Kennedy Space Center in Florida bound for the ISS and the high frontier with Chris Ferguson as Space Shuttle Commander. Credit: Ken Kremer/kenkremer.com

All Together Now!

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That’s a lot of power under one roof! For the first time in… well, ever… all fifteen Space Shuttle Main Engines (SSMEs) are together inside NASA’s Engine Shop at Kennedy Space Center. They will be prepped for shipment to Stennis Space Center in Mississippi where they’ll become part of the propulsion used on NASA’s next generation heavy-lift rocket: the Space Launch System.

The engines, built by Pratt & Whitney Rocketdyne, are each 14 feet (4.2 meters) long & 7.5 feet (2.3 meters) in diameter at the end of its nozzle, and weighs approximately 7,000 lbs (3175 kg).

Photo from a test firing of an SSME at the Stennis Space Center in 1981. Credit: NASA.

Each engine is capable of generating a force of nearly 400,000 pounds (lbf) of thrust at liftoff, and consumes 350 gallons (1,340 liters) of fuel per second. They are engineered to burn liquid hydrogen and liquid oxygen, creating exhaust composed primarily of water vapor.

The engines will be incorporated into the Space Launch System (SLS), which is designed to carry the Orion Multi-Purpose Crew Vehicle – also currently in development – as well as serve as backup for commercial and international transportation to the ISS. By utilizing current technology and adapting it for future needs, NASA will be able to make the next leap in human spaceflight and space exploration – while getting the most “bang” out of the taxpayers’ bucks.

“NASA has been making steady progress toward realizing the president’s goal of deep space exploration, while doing so in a more affordable way. We have been driving down the costs on the Space Launch System and Orion contracts by adopting new ways of doing business and project hundreds of millions of dollars of savings each year.” 

–  NASA Deputy Administrator Lori Garver

Nine of the 15 SSMEs await shipment inside NASA's Engine Shop. Each weighs approximately 7,000 lbs. Credit: NASA.

While it’s sad to see these amazing machines removed from the shuttles, it’s good to know that they still have plenty of life left in them and will soon once again be able to take people into orbit and beyond!

Read more about the Space Launch System here.