First SLS Engine Blazes to Life in Mississippi Test Firing Igniting NASA’s Path to Deep Space

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
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
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.

Ken Kremer

NASA’s 135th and final shuttle mission takes flight on July 8, 2011 at 11:29 a.m. from the Kennedy Space Center in Florida bound for the ISS and the high frontier with Chris Ferguson as Space Shuttle Commander. Credit: Ken Kremer/kenkremer.com

STS-135: Last launch using RS-25 engines that will now power NASA’s SLS deep space exploration rocket. NASA’s 135th and final shuttle mission takes flight on July 8, 2011 at 11:29 a.m. from the Kennedy Space Center in Florida bound for the ISS and the high frontier with Chris Ferguson as Space Shuttle Commander. Credit: Ken Kremer/kenkremer.com

US Heavy Lift Mars Rocket Passes Key Review and NASA Sets 2018 Maiden Launch Date

Artist concept of NASA’s Space Launch System (SLS) 70-metric-ton configuration launching to space. SLS will be the most powerful rocket ever built for deep space missions, including to an asteroid and ultimately to Mars. Credit: NASA/MSFC
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After a thorough review of cost and engineering issues, NASA managers formally approved the development of the agency’s mammoth heavy lift rocket – the Space Launch System or SLS – which will be the world’s most powerful rocket ever built and is intended to take astronauts farther beyond Earth into deep space than ever before possible – to Asteroids and Mars.

The maiden test launch of the SLS is targeted for November 2018 and will be configured in its initial 70-metric-ton (77-ton) version, top NASA officials announced at a briefing for reporters on Aug. 27.

On its first flight known as EM-1, the SLS will also loft an uncrewed Orion spacecraft on an approximately three week long test flight taking it beyond the Moon to a distant retrograde orbit, said William Gerstenmaier, associate administrator for the Human Explorations and Operations Mission Directorate at NASA Headquarters in Washington, at the briefing.

Previously NASA had been targeting Dec. 2017 for the inaugural launch from the Kennedy Space Center in Florida – a slip of nearly one year.

But the new Nov. 2018 target date is what resulted from the rigorous assessment of the technical, cost and scheduling issues.

This artist concept shows NASA’s Space Launch System, or SLS, rolling to a launch pad at Kennedy Space Center at night. SLS will be the most powerful rocket in history, and the flexible, evolvable design of this advanced, heavy-lift launch vehicle will meet a variety of crew and cargo mission needs.   Credit:  NASA/MSFC
This artist concept shows NASA’s Space Launch System, or SLS, rolling to a launch pad at Kennedy Space Center at night. SLS will be the most powerful rocket in history, and the flexible, evolvable design of this advanced, heavy-lift launch vehicle will meet a variety of crew and cargo mission needs. Credit: NASA/MSFC

The decision to move forward with the SLS comes after a wide ranging review of the technical risks, costs, schedules and timing known as Key Decision Point C (KDP-C), said Associate Administrator Robert Lightfoot, at the briefing. Lightfoot oversaw the review process.

“After rigorous review, we’re committing today to a funding level and readiness date that will keep us on track to sending humans to Mars in the 2030s – and we’re going to stand behind that commitment,” said Lightfoot. “Our nation is embarked on an ambitious space exploration program.”

“We are making excellent progress on SLS designed for missions beyond low Earth orbit,” Lightfoot said. “We owe it to the American taxpayers to get it right.”

He said that the development cost baseline for the 70-metric ton version of the SLS was $7.021 billion starting from February 2014 and continuing through the first launch set for no later than November 2018.

Lightfoot emphasized that NASA is also building an evolvable family of vehicles that will increase the lift to an unprecedented lift capability of 130 metric tons (143 tons), which will eventually enable the deep space human missions farther out than ever before into our solar system, leading one day to Mars.

“It’s also important to remember that we’re building a series of launch vehicles here, not just one,” Lightfoot said.

Blastoff of NASA’s Space Launch System (SLS) rocket and Orion crew vehicle from the Kennedy Space Center, Florida.   Credit: NASA/MSFC
Blastoff of NASA’s Space Launch System (SLS) rocket and Orion crew vehicle from the Kennedy Space Center, Florida. Credit: NASA/MSFC

Lightfoot and Gerstenmaier both indicated that NASA hopes to launch sooner, perhaps by early 2018.

“We will keep the teams working toward a more ambitious readiness date, but will be ready no later than November 2018,” said Lightfoot.

The next step is conduct the same type of formal KDP-C reviews for the Orion crew vehicle and Ground Systems Development and Operations programs.

The first piece of SLS flight hardware already built and to be tested in flight is the stage adapter that will fly on the maiden launch of Orion this December atop a ULA Delta IV Heavy booster during the EFT-1 mission.

The initial 70-metric-ton (77-ton) version of the SLS stands 322 feet tall and provides 8.4 million pounds of thrust. That’s already 10 percent more thrust at launch than the Saturn V rocket that launched NASA’s Apollo moon landing missions, including Apollo 11, and it can carry more than three times the payload of the now retired space shuttle orbiters.

The core stage towers over 212 feet (64.6 meters) tall with a diameter of 27.6 feet (8.4 m) and stores cryogenic liquid hydrogen and liquid oxygen. Boeing is the prime contractor for the SLS core stage.

The first stage propulsion is powered by 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 pressure vessels for the Orion crew capsule, including EM-1 and EFT-1, are also being manufactured at MAF. And all of the External Tanks for the space shuttles were also fabricated at MAF.

The airframe structure for the first Dream Chaser astronaut taxi to low Earth orbit is likewise under construction at MAF as part of NASA’s commercial crew program.

The first crewed flight of the SLS is set for the second launch on the EM-2 mission around the 2020/2021 time frame, which may visit a captured near Earth asteroid.

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

Ken Kremer