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.
The core stage for the first flight of NASA’s Space Launch System rocket is seen in the B-2 Test Stand during a scheduled eight minute duration hot fire test, Saturday, Jan. 16, 2021, at NASA’s Stennis Space Center near Bay St. Louis, Mississippi.
Credits: NASA/Robert Markowitz
In November of 2021, NASA will embark on a new era of space exploration as they make the inaugural launch of the Space Launch System (SLS). When it enters service, this booster will be the most powerful rocket since the Saturn V, which took the Apollo astronauts to the Moon. This is fitting since the SLS will be the rocket returning astronauts to the Moon by 2024 (as part of Project Artemis).
To get the SLS ready for its first launch, NASA has been running the Core Stage through a series of tests designed to test all the systems and components of the heavy-launch system – collectively known as a “Green Run.” The next step in this process will be a second Green Run Hot Fire Test, where all four RS-25 engines on the SLS Core Stage will fire at once to show they can operate as part of a single integrated system.
Today, at close to 04:30 PM local time (CST), NASA achieved a major milestone with the development of the Space Launch System (SLS) – the heavy launch system they will use to send astronauts back to the Moon and crewed missions to Mars. As part of a Green Run Hot Fire Test, all four RS-25 engines on the SLS Core Stage were fired at once as part of the first top-to-bottom integrated test of the stage’s systems.
This test is the last hurdle in an eight-step validation process before the Core Stage can be mated with its Solid Rocket Boosters (SRBs) and sent on its maiden voyage around the Moon (Artemis I) – which is currently scheduled to happen sometime in November of 2021.
With the passage of the NASA Authorization Act of 2010, work began on a launch vehicle that would carry cargo and crews back to the Moon and beyond. This vehicle is known as the Space Launch System (SLS), a heavy-launch system that (once fully operational) will be the most powerful rocket in the world since the Saturn V– the venerable vehicle that took the Apollo astronauts to the Moon.
Unfortunately, the development of the SLS has suffered from multiple delays over the past few years, causing no shortage of complications. However, engineering teams at NASA’s Stennis Space Center near St. Louis, Mississippi, recently completed a Green Run of the SLS’s Core Stage, which involved testing the rocket’s critical systems in preparation for its inaugural launch by November of 2021.
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
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.
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 Story/imagery updated
See video below of full duration hot-fire test[/caption]
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
“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
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
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
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.
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
The RS-25 engine fires up for a 500-second test Jan. 9, 2015 at NASA's Stennis Space Center near Bay St. Louis, Mississippi. Credit: NASA
NASA’s goal of sending astronauts to deep space took a major step forward when the first engine of the type destined to power the mighty Space Launch System (SLS) exploration rocket blazed to life during a successful test firing at the agency’s Stennis Space Center near Bay St. Louis, Mississippi.
The milestone hot fire test conducted on Jan. 9, involved igniting a shuttle-era RS-25 space shuttle main engine for 500 seconds on the A-1 test stand at Stennis.
A quartet of RS-25s, formerly used to power the space shuttle orbiters, will now power the core stage of the SLS which will be the most powerful rocket the world has ever seen.
“The RS-25 is the most efficient engine of its type in the world,” said Steve Wofford, manager of the SLS Liquid Engines Office at NASA’s Marshall Space Flight Center, in Huntsville, Alabama, where the SLS Program is managed. “It’s got a remarkable history of success and a great experience base that make it a great choice for NASA’s next era of exploration.”
The SLS is NASA’s mammoth heavy lift rocket now under development. It is intended to launch the Orion deep space crew capsule and propel astronauts aboard to destinations far beyond Earth and farther into space than ever before possible – beyond the Moon, to Asteroids and Mars.
The over eight minute RS-25 engine test firing provided NASA engineers with critical data on the engine controller unit, which is the “brain” of the engine providing communications between the engine and the vehice, and inlet pressure conditions.
“The controller also provides closed-loop management of the engine by regulating the thrust and fuel mixture ratio while monitoring the engine’s health and status. The new controller will use updated hardware and software configured to operate with the new SLS avionics architecture,” according to NASA.
This also marked the first test of a shuttle-era RS-25 since the conclusion of space shuttle main engine testing in 2009.
For the SLS, the RS-25 will be configured and operated differently from their use when attached as a trio to the base of the orbiters during NASA’s four decade long Space Shuttle era that ended with the STS-135 mission in July 2011.
“We’ve made modifications to the RS-25 to meet SLS specifications and will analyze and test a variety of conditions during the hot fire series,” said Wofford
“The engines for SLS will encounter colder liquid oxygen temperatures than shuttle; greater inlet pressure due to the taller core stage liquid oxygen tank and higher vehicle acceleration; and more nozzle heating due to the four-engine configuration and their position in-plane with the SLS booster exhaust nozzles.”
Watch this video of the RS-25 engine test:
Video Caption: The RS-25 engine that will drive NASA’s new rocket, the Space Launch System, to deep space blazed through its first successful test Jan. 9 at the agency’s Stennis Space Center near Bay St. Louis, Mississippi. Credit: NASA TV
The SLS core stage stores the cryogenic liquid hydrogen and liquid oxygen that fuel the RS-25 first stage engines.
“This first hot-fire test of the RS-25 engine represents a significant effort on behalf of Stennis Space Center’s A-1 test team,” said Ronald Rigney, RS-25 project manager at Stennis.
“Our technicians and engineers have been working diligently to design, modify and activate an extremely complex and capable facility in support of RS-25 engine testing.”
The Jan. 9 engine test was just the first of an extensive series planned. After an upgrade to the high pressure cooling system, an initial series of eight development tests will begin in April 2015 totaling 3,500 seconds of firing time.
A close-up view of the RS-25 engine from the test stand. Credit: NASA
The SLS core stage is being built at NASA’s Michoud Assembly Facility in New Orleans.
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.
“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.
The core stage towers over 212 feet (64.6 meters) tall and sports a diameter of 27.6 feet (8.4 m).
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/AmericaSpace
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.
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
