NASA conducts an RS-25 hot fire on the Fred Haise Test Stand at Stennis Space Center in south Mississippi on Dec. 14. Credit: NASA/SSC
On November 16th, NASA launched the first mission of the Artemis Program (Artemis I), which splashed down three and a half weeks later. This uncrewed mission saw the Space Launch System (SLS) send an Orion spacecraft far beyond the orbit of the Moon, establishing a new record for distance traveled by a mission and the amount of time spent beyond Low Earth Orbit (LEO). Powering the core stage of the SLS were four Aerojet Rocketdyne RS-25s, the same engines used by the Space Shuttle – known as the Space Shuttle Main Engine (SSME).
By the end of the decade, NASA plans to mount a total of six Artemis launches that will include crewed missions to the surface, the creation of the Artemis Basecamp, and the deployment of the Lunar Gateway. NASA also plans to upgrade key components in the mission architecture along the way, which include replacing the Space Shuttle Era engines with the newly-designed RS-25E. On December 14th, NASA tested this engine for the first time at the Stennis Space Center in Mississippi, completing a hot fire test that lasted for just under three and a half minutes (209.5 seconds).
The core stage for the first flight of NASA’s Space Launch System rocket is seen in the B-2 Test Stand during a second hot fire test, Thursday, March 18, 2021, at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. The four RS-25 engines fired for the full-duration of 8 minutes during the test and generated 1.6 million pounds of thrust. The hot fire test is the final stage of the Green Run test series, a comprehensive assessment of the Space Launch System’s core stage prior to launching the Artemis I mission to the Moon. Photo Credit: (NASA/Robert Markowitz)
When NASA’s Space Launch System (SLS) is fully integrated, assembled, and finished with testing, it will be the most powerful rocket since the Saturn V that carried the Apollo astronauts to the Moon. To get it there, NASA has been conducting a testing campaign known as the Green Run, an 8-step assessment that culminates in a test-firing of all four of the Core’s RS-25 engines (aka. a “Hot Fire” test).
On January 16th, NASA made its first attempt at a Green Run Hot Fire test at the Stennis Space Center’s B-2 Test Stand in Mississippi, which only lasted for about one minute. Another attempt was made on Thursday, March 18th, where all four engines fired for 8 minutes and 19 seconds. This successful fire test is a crucial milestone for the SLS and brings it one step closer to sending astronauts back to the Moon.
NASA engineers conduct 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, 2017. The RS-25 engine, with the flight controller, was test fired for a full-duration 500 seconds. Credits: NASA/SSC
NASA engineers conduct 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, 2017. The RS-25 engine, with the flight controller, was test fired for a full-duration 500 seconds. Credits: NASA/SSC
Engineers carried out a critical hot fire engine test firing with the first new engine controlling ‘brain’ that will command the shuttle-era liquid fueled engines powering the inaugural mission of NASA’s new Space Launch System (SLS) megarocket.
The first integrated SLS launch combining the SLS-1 rocket and Orion EM-1 deep space crew capsule could liftoff as soon as late 2018 on a mission around the Moon and back.
The full duration static fire test involved an RS-25 engine integrated with the first engine controller flight unit that will actually fly on the maiden SLS launch and took place on Thursday, March 23 at the agency’s Stennis Space Center in Bay St. Louis, Mississippi.
The 500 second-long test firing was conducted with the engine controller flight unit installed on RS-25 development engine no. 0528 on the A-2 Test Stand at Stennis.
The RS-25 engine controller is the ‘brain’ that commands the RS-25 engine and communicates between the engine and the SLS rocket. It is about the size of a dorm refrigerator.
RS-25 new engine controller. Credit: NASA/SSC
The newly developed engine controller is a modern version from the RS-25 controller that helped propel all 135 space shuttle missions to space.
“This an important – and exciting – step in our return to deep space missions,” Stennis Director Rick Gilbrech said. “With every test of flight hardware, we get closer and closer to launching humans deeper into space than we ever have traveled before.”
The modernized RS-25 engine controller was funded by NASA and created in a collaborative effort of engineers from NASA, RS-25 prime contractor Aerojet Rocketdyne of Sacramento, California, and subcontractor Honeywell of Clearwater, Florida.
“The controller manages the engine by regulating the thrust and fuel mixture ratio and monitors the engine’s health and status – much like the computer in your car,” say NASA officials.
“The controller then communicates the performance specifications programmed into the controller and monitors engine conditions to ensure they are being met, controlling such factors as propellant mixture ratio and thrust level.”
A quartet of RS-25 engines, leftover from the space shuttle era and repeatedly reused, will be installed at the base of the core stage to power the SLS at liftoff, along with a pair of extended solid rocket boosters.
The four RS-25 core stage engine will provide a combined 2 million pounds of thrust at liftoff.
In addition to being commanded by the new engine controller, the engines are being upgraded in multiple ways for SLS. For example they will operate at a higher thrust level and under different operating conditions compared to shuttle times.
To achieve the higher thrust level required, the RS-25 engines must fire at 109 percent of capability for SLS compared to operating at 104.5 percent of power level capability for shuttle flights.
The RS-25 engines “also will operate with colder liquid oxygen and engine compartment temperatures, higher propellant pressure and greater exhaust nozzle heating.”
SLS will be the world’s most powerful rocket and send astronauts on journeys into deep space, further than human have ever travelled before.
For SLS-1 the mammoth booster will launch 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.
NASA engineers conduct 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, 2017. The RS-25 engine, with the flight controller, was test fired for a full-duration 500 seconds. Credits: NASA/SSC
The next step is evaluating the engine firing test results, confirming that all test objectives were met and certifying that the engine controller can be removed from the RS-25 development engine and then be installed on one of four flight engines that will help power SLS-1.
During 2017, two additional engine controllers for SLS-1 will be tested on the same development engine at Stennis and then be installed on flight engines after certification.
Finally, “the fourth controller will be tested when NASA tests the entire core stage during a “green run” on the B-2 Test Stand at Stennis. That testing will involve installing the core stage on the stand and firing its four RS-25 flight engines simultaneously, as during a mission launch,” says NASA.
Numerous RS-25 engine tests have been conducted at Stennis over more than 4 decades to certify them as flight worthy for the human rated shuttle and SLS rockets.
NASA engineers successfully conducted a development test of the RS-25 rocket engine Thursday, Aug. 18, 2016 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
Although NASA is still targeting SLS-1 for launch in Fall 2018 on an uncrewed mission, the agency is currently conducting a high level evaluation to determine whether the Orion EM-1 capsule can be upgraded in time to instead fly a human crewed mission with two astronauts before the end of 2019 – as I reported here.
The Orion EM-1 capsule is currently being manufactured at the Neil Armstrong Operations and Checkout Building at the Kennedy Space Center by prime contractor Lockheed Martin.
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.
Aerojet Rocketdyne technicians inspect the engine controller that will be used for the first integrated flight of NASA’s Space Launch System and Orion in late 2018. The engine controller was installed on RS-25 development engine no. 0528 for testing at Stennis Space Center on the A-2 Test Stand on March 23, 2017. The RS-25 engine, with the flight controller, was test fired for a full-duration 500 seconds. Credits: NASA/SSC
NASA engineers successfully conducted a development test of the RS-25 rocket engine Thursday, Aug. 18, 2016 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
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
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 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
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.
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
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
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
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
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
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 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) 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
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
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
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
Space Launch System (SLS) core stage engine section finishes welding at the Vertical Assembly Center at NASA's Michoud Assembly Facility in New Orleans for maiden flight of SLS rocket. Credit: NASA
Space Launch System (SLS) core stage engine section finishes welding at the Vertical Assembly Center at NASA’s Michoud Assembly Facility in New Orleans for maiden flight of SLS rocket. Credit: NASA
One weld at a time, the flight hardware for NASA’s mammoth new Space Launch System (SLS) booster has at last started taking shape, promising to turn years of planning and engineering discussions into reality and a rocket that will one day propel our astronauts on a ‘Journey to Mars.’
The first actual SLS flight hardware has been assembled, leaping from engineering blueprints on computer screens to individual metallic components that technicians are feeding into NASA’s gigantic “Welding Wonder” machine at the agency’s Michoud Assembly Facility in New Orleans.
Technicians are bending metal and have now finished welding together the pieces of flight hardware forming the first major SLS flight component – namely the engine section that sits at the base of the SLS core stage.
The core stage towers over 212 feet (64.6 meters) tall, sports a diameter of 27.6 feet (8.4 m) and stores the cryogenic liquid hydrogen and liquid oxygen that feeds and fuels the boosters RS-25 engines.
A liquid oxygen tank confidence article for NASA’s new rocket, the Space Launch System, completes final welding on the Vertical Assembly Center at Michoud Assembly Facility in New Orleans. Credit: NASA/Michoud/Steven Seipel
SLS will be the most powerful rocket the world has ever seen. It will propel astronauts in the Orion capsule on deep space missions, first back to the Moon by around 2021, then to an asteroid around 2025 and then beyond to the Red Planet in the 2030s – NASA’s overriding and agency wide goal.
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 welding work is carried out in the massive 170-foot-tall Vertical Assembly Center (VAC) at Michoud. Boeing is the prime contractor for the SLS core stage.
On Sept. 12, 2014, NASA Administrator Charles Bolden officially unveiled VAC as the world’s largest welder at Michoud.
“This rocket is a game changer in terms of deep space exploration and will launch NASA astronauts to investigate asteroids and explore the surface of Mars while opening new possibilities for science missions, as well,” said NASA Administrator Charles Bolden during the ribbon-cutting ceremony at Michoud.
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
Each of the RS-25’s engines generates some 500,000 pounds of thrust, fueled by cryogenic liquid hydrogen and liquid oxygen. They are recycled for their original use as space shuttle main engines
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.
The SLS weld team has been busy. Technicians have already assembled a qualification version of the engine section on the Vertical Assembly Center at Michoud. Later this year it will be shipped to NASA’s Marshall Space Flight Center in Huntsville, Alabama, to undergo structural loads testing.
In March, they also completed welding of a liquid oxygen tank confidence article on the Vertical Assembly Center. And in February they welded the liquid hydrogen tank confidence article.
SLS core stage will be welded together from barrels and domes using the Vertical Assembly Center (VAC) at NASA’s Michoud Assembly Facility. Credit: Ken Kremer/ kenkremer.com
The SLS core stage is comprised of five major structures: the forward skirt, the liquid oxygen tank, the intertank, the liquid hydrogen tank and the engine section.
The tanks are assembled by joining previously manufactured domes, rings and barrels 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 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.
According to the current schedule, NASA plans to finish all welding for the core stage — including confidence, qualification and flight hardware — of the SLS-1 rocket sometime this summer.
Engineers are constructing the confidence and qualification hardware units to verify that the welding equipment and procedures work exactly as planned.
“The confidence will also be used in developing the application process for the thermal protection system, which is the insulation foam that gives the tank its orange color,” say NASA officials.
Altogether , the SLS first stage propulsion comprises the four RS-25 space shuttle main engines and a pair of enhanced five segment solid rocket boosters (SRBs) also derived from the shuttles four segment boosters.
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) version with a liftoff thrust of 8.4 million pounds.
Meanwhile the welded skeletal backbone for the Orion EM-1 mission recently arrived at the Kennedy Space Center on Feb. 1 for outfitting with all the systems and subsystems necessary for flight.
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.
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 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 first RS-25 flight engine, No. 2059, is placed on the A-1 Test Stand at Stennis Space Center, Miss. The engines were built by Aerojet Rocketdyne and are being tested in 2015 and 2016 to certify them to fly on NASA’s new Space Launch System (SLS) rocket. SLS-1 will launch on its first uncrewed mission in 2018. Credit: NASA
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
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.
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
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
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.
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.
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
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The SLS, America’s first human-rated heavy lift rocket intended to carry astronautsto deep space destinations since NASA’s Apollomoon landing era Saturn V, has passed a key design milestone known as the critical design review (CDR) thereby clearing the path to full scale fabrication.
NASA also confirmed they have dropped the Saturn V white color motif of the mammoth rocket in favor of burnt orange to reflect the natural color of the SLS boosters first stage cryogenic core. The agency also decided to add stripes to the huge solid rocket boosters.
NASA announced that the Space Launch System (SLS) has “completed all steps needed to clear a critical design review (CDR)” – meaning that the design of all the rockets components are technically acceptable and the agency can continue with full scale production towards achieving a maiden liftoff from the Kennedy Space Center in Florida in 2018.
“We’ve nailed down the design of SLS,” said Bill Hill, deputy associate administrator of NASA’s Exploration Systems Development Division, in a NASA statement.
Artist concept of the SLS Block 1 configuration on the Mobile Launcher at KSC. Credit: NASA/MSFC
Blastoff of the NASA’s first SLS heavy lift booster (SLS-1) carrying an unmanned test version of NASA’s Orioncrew capsule is targeted for no later than November 2018.
Indeed the SLS will be the most powerful rocket the world has ever seen starting with its first liftoff. It will propel our astronauts on journey’s further into space than ever before.
SLS is “the first vehicle designed to meet the challenges of the journey to Mars and the first exploration class rocket since the Saturn V.”
Crews seated inside NASA’s Orion crew module bolted atop the SLS will rocket to deep space destinations including the Moon, asteroids and eventually the Red Planet.
“There have been challenges, and there will be more ahead, but this review gives us confidence that we are on the right track for the first flight of SLS and using it to extend permanent human presence into deep space,” Hill stated.
The core stage (first stage) of the SLS will be powered by four RS-25 engines and a pair of five-segment solid rocket boosters (SRBs) that will generate a combined 8.4 million pounds of liftoff thrust in its inaugural Block 1 configuration, with a minimum 70-metric-ton (77-ton) lift capability.
Overall the SLS Block 1 configuration will be some 10 percent more powerful than the Saturn V rockets that propelled astronauts to the Moon, including Neil Armstrong, the first human to walk on the Moon during Apollo 11 in July 1969.
Graphic shows Block I configuration of NASA’s Space Launch System (SLS). Credits: NASA/MSFC
The SLS core stage is derived from the huge External Tank (ET) that fueled NASA Space Shuttle’s for three decades. It is a longer version of the Shuttle ET.
NASA initially planned to paint the SLS core stage white, thereby making it resemble the Saturn V.
But since the natural manufacturing color of its insulation during fabrication is burnt orange, managers decided to keep it so and delete the white paint job.
“As part of the CDR, the program concluded the core stage of the rocket and Launch Vehicle Stage Adapter will remain orange, the natural color of the insulation that will cover those elements, instead of painted white,” said NASA.
There is good reason to scrap the white color motif because roughly 1000 pounds of paint can be saved by leaving the tank with its natural orange pigment.
This translates directly into another 1000 pounds of payload carrying capability to orbit.
“Not applying the paint will reduce the vehicle mass by potentially as much as 1,000 pounds, resulting in an increase in payload capacity, and additionally streamlines production processes,” Shannon Ridinger, NASA Public Affairs spokeswomen told Universe Today.
After the first two shuttle launches back in 1981, the ETs were also not painted white for the same reason – in order to carry more cargo to orbit.
“This is similar to what was done for the external tank for the space shuttle. The space shuttle was originally painted white for the first two flights and later a technical study found painting to be unnecessary,” Ridinger explained.
Artist concept of the Block I configuration of NASA’s Space Launch System (SLS). The SLS Program has completed its critical design review, and the program has concluded that the core stage of the rocket will remain orange along with the Launch Vehicle Stage Adapter, which is the natural color of the insulation that will cover those elements. Credits: NASA
NASA said that the CDR was completed by the SLS team in July and the results were also further reviewed over several more months by a panel of outside experts and additionally by top NASA managers.
“The SLS Program completed the review in July, in conjunction with a separate review by the Standing Review Board, which is composed of seasoned experts from NASA and industry who are independent of the program. Throughout the course of 11 weeks, 13 teams – made up of senior engineers and aerospace experts across the agency and industry – reviewed more than 1,000 SLS documents and more than 150 GB of data as part of the comprehensive assessment process at NASA’s Marshall Space Flight Center in Huntsville, Alabama, where SLS is managed for the agency.”
“The Standing Review Board reviewed and assessed the program’s readiness and confirmed the technical effort is on track to complete system development and meet performance requirements on budget and on schedule.”
The final step of the SLS CDR was completed this month with another extremely thorough assessment by NASA’s Agency Program Management Council, led by NASA Associate Administrator Robert Lightfoot.
“This is a major step in the design and readiness of SLS,” said John Honeycutt, SLS program manager.
The CDR was the last of four reviews that examine SLS concepts and designs.
NASA says the next step “is design certification, which will take place in 2017 after manufacturing, integration and testing is complete. The design certification will compare the actual final product to the rocket’s design. The final review, the flight readiness review, will take place just prior to the 2018 flight readiness date.”
“Our team has worked extremely hard, and we are moving forward with building this rocket. We are qualifying hardware, building structural test articles, and making real progress,” Honeycutt elaborated.
Numerous individual components of the SLS core stage have already been built and their manufacture was part of the CDR assessment.
The SLS core stage is being built at NASA’s Michoud Assembly Facility in New Orleans. It stretches over 200 feet tall and is 27.6 feet in diameter and will carry cryogenic liquid hydrogen and liquid oxygen fuel for the rocket’s four RS-25 engines.
On Sept. 12, 2014, NASA Administrator Charles Bolden officially unveiled the world’s largest welder at Michoud, that will be used to construct the core stage, as I reported earlier during my on-site visit – here.
NASA decided that the SRBs will be painted with something like racing stripes.
“Stripes will be painted on the SRBs and we are still identifying the best process for putting them on the boosters; we have multiple options that have minimal impact to cost and payload capability, ” Ridinger stated.
With the successful completion of the CDR, the components of the first core stage can now proceed to assembly of the finished product and testing of the RS-25 engines and boosters can continue.
“We’ve successfully completed the first round of testing of the rocket’s engines and boosters, and all the major components for the first flight are now in production,” Hill explained.
View of NASA’s future SLS/Orion launch pad at Space Launch Complex 39B from atop Mobile Launcher at the Kennedy Space Center in Florida. Former Space Shuttle launch pad 39B is now undergoing renovations and upgrades to prepare for SLS/Orion flights starting in 2018. Credit: Ken Kremer/kenkremer.com
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 (KSC).
The SLS/Orion stack will roll out to pad 39B atop the Mobile Launcher now under construction – as detailed in my recent story and during visit around and to the top of the ML at KSC.
Looking up from beneath the enlarged exhaust hole of the Mobile Launcher to the 380 foot-tall tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars. The ML will support NASA’s Space Launch System (SLS) and Orion spacecraft during Exploration Mission-1 at NASA’s Kennedy Space Center in Florida. 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.
Wide view of the new welding tool at the Vertical Assembly Center at NASA’s Michoud Assembly Facility in New Orleans at a ribbon-cutting ceremony Sept. 12, 2014. Credit: Ken Kremer – kenkremer.com
Looking up from beneath the enlarged exhaust hole of the Mobile Launcher to the 380 foot-tall tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars. The ML will support NASA's Space Launch System (SLS) and Orion spacecraft during Exploration Mission-1 at NASA's Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com
Looking up from beneath the enlarged exhaust hole of the Mobile Launcher to the 380 foot-tall tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars. The ML will support NASA’s Space Launch System (SLS) and Orion spacecraft during Exploration Mission-1 at NASA’s Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com
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KENNEDY SPACE CENTER, FL – NASA’s Mobile Launcher (ML) is undergoing major upgrades and modifications at the Kennedy Space Center in Florida enabling the massive structure to launch the agency’s mammoth Space Launch System (SLS) rocket and Orion crew capsule on a grand ‘Journey to Mars.’
“We just finished up major structural steel modifications to the ML, including work to increase the size of the rocket exhaust hole,” Eric Ernst, NASA Mobile Launch project manager, told Universe Today during an exclusive interview and inspection tour up and down the Mobile Launcher.
Construction workers are hard at work upgrading and transforming the 380-foot-tall, 10.5-million-pound steel structure into the launcher for SLS and Orion – currently slated for a maiden blastoff no later than November 2018 on Exploration Mission-1 (EM-1).
“And now we have just started the next big effort to get ready for SLS.”
SLS and Orion are NASA’s next generation human spaceflight vehicles currently under development and aimed at propelling astronauts to deep space destinations, including the Moon and an asteroid in the 2020s and eventually a ‘Journey to Mars’ in the 2030s.
Floor level view of the Mobile Launcher and enlarged exhaust hole with 380 foot-tall launch tower astronauts will ascend as their gateway for missions to the Moon, Asteroids and Mars. The ML will support NASA’s Space Launch System (SLS) and Orion spacecraft for launches from Space Launch Complex 39B at the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com
The mobile launcher was originally built several years ago to accommodate NASA’s less powerful, lighter and now cancelled Ares-1 rocket. It therefore requires extensive alterations to accommodate the vastly more powerful and heavier SLS rocket.
“The ML was initially developed for Ares 1, a much smaller rocket,” Ernst explained to Universe Today.
“So the exhaust hole was much smaller.”
Whereas the Ares-1 first stage booster was based on using a single, more powerful version of the Space Shuttle Solid Rocket Boosters, the SLS first stage is gargantuan and will be the most powerful rocket the world has ever seen.
The SLS first stage comprises two shuttle derived solid rocket boosters and four RS-25 power plants recycled from their earlier life as space shuttle main engines (SSMEs). They generate a combined 8.4 million pounds of thrust – exceeding that of NASA’s Apollo Saturn V moon landing rocket.
Therefore the original ML exhaust hole had to be gutted and nearly tripled in width.
“The exhaust hole used to be about 22 x 22 feet,” Ernst stated.
“Since the exhaust hole was much smaller, we had to deconstruct part of the tower at the base, in place. The exhaust hole had to be made much bigger to accommodate the SLS.”
Construction crews extensively reworked the exhaust hole and made it far wider to accommodate SLS compared to the smaller one engineered and already built for the much narrower Ares-1, which was planned to generate some 3.6 million pounds of thrust.
“So we had to rip out a lot of steel,” Mike Canicatti, ML Construction Manager told Universe Today.
“For the exhaust hole [at the base of the tower], lots of pieces of [existing] steel were taken out and other new pieces were added, using entirely new steel.”
“The compartment for the exhaust hole used to be about 22 x 22 feet, now it’s about 34 x 64 feet.”
Looking down to the enlarged 64 foot wide exhaust hole from the top of NASA’s 380 foot-tall Mobile Launch tower. Astronauts will board the Orion capsule atop the Space Launch System (SLS) rocket for launches from Space Launch Complex 39B the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com
In fact this involved the demolition of over 750 tons of old steel following by fabrication and installation of more than 1,000 tons of new steel. It was also reinforced due to the much heavier weight of SLS.
“It was a huge effort and structural engineers did their job. The base was disassembled and reassembled in place” – to enlarge the exhaust hole.
“So basically we gutted major portions of the base out, put in new walls and big structural girders,” Ernst elaborated.
“And we just finished up that major structural steel modification on the exhaust hole.”
Top view across the massive 34 foot-wide, 64 foot-long exhaust hole excavated out of NASA’s Mobile Launcher that will support launches of the Space Launch System (SLS) rocket from Space Launch Complex 39B at the Kennedy Space Center in Florida. Credit: Ken Kremer/kenkremer.com
Meanwhile the 380 foot-tall tower that future Orion astronauts will ascend was left in place.
“The tower portion itself did not need to be disassembled.”
The Ares rockets originally belonged to NASA’s Constellation program, whose intended goal was returning American astronauts to the surface of the Moon by 2020.
Ares-1 was slated as the booster for the Orion crew capsule. However, President Obama cancelled Constellation and NASA’s Return to the Moon soon after entering office.
Since then the Obama Administration and Congress worked together in a bipartisan manner together to fashion a new space hardware architecture and granted approval for development of the SLS heavy lift rocket to replace the Ares-1 and heavy lift Ares-5.
Sending astronauts on a ‘Journey to Mars’ is now NASA’s agency wide and overarching goal for the next few decades of human spaceflight.
But before SLS can be transported to its launch pad at Kennedy’s Space Launch Complex 39-B for the EM-1 test flight the next big construction step has to begin.
“So now we have just started the next big effort to get ready for SLS.”
This involves installation of Ground Support Equipment (GSE) and a wide range of launch support services and systems to the ML.
“The next big effort is the GSE installation contract,” Ernst told me.
“We have about 40+ ground support and facility systems to be installed on the ML. There are about 800 items to be installed, including about 300,000-plus feet of cable and several miles of piping and tubing.”
“So that’s the next big effort to get ready for SLS. It’s about a 1.5 year contract and it was just awarded to J.P. Donovan Construction Inc. of Rockledge, Florida.”
“The work just started at the end of August.”
NASA currently plans to roll the ML into the Vehicle Assembly Building in early 2017 for stacking of SLS and Orion for the EM-1 test flight.
View of NASA’s future SLS/Orion launch pad at Space Launch Complex 39B from atop Mobile Launcher at the Kennedy Space Center in Florida. Former Space Shuttle launch pad 39B is now undergoing renovations and upgrades to prepare for SLS/Orion flights starting in 2018. Credit: Ken Kremer/kenkremer.com
The SLS/Orion mounted stack atop the ML will then roll out to Space Launch Complex 39B for the 2018 launch from the Kennedy Space Center.
Pad 39B is also undergoing radical renovations and upgrades, transforming it from its use for NASA’s now retired Space Shuttle program into a modernized 21st century launch pad. Watch for my upcoming story.
Artist concept of the SLS Block 1 configuration mounted on the Mobile Launcher. Credit: NASA
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
View from atop NASA’s SLS mobile launcher at the Kennedy Space Center, looking out to United Launch Alliance Atlas V rocket with MUOS-4 US Navy communications satellite poised at pad 41 at Cape Canaveral Air Force Station, FL, ‘prior to launch on Sept. 2, 2015. EDT. Credit: Ken Kremer/kenkremer.com
