Spaceflight Insider

NASA / ATK prep five-segment SLS booster for March 11 test fire

QM-1 SRB ATK Promontory, UT. Photo Credit: ATK

QM-1 SRB in ATK test Stand - Promontory, Utah. Photo Credit: ATK

PROMONTORY, Utah — The next major milestone in the development of NASA’s new human-rated heavy-lift vehicle, the Space Launch System (SLS ), is scheduled to take place on March 11 — a planned test of the largest solid rocket booster (SRB) ever built for flight. It marks a distinct ramp up in the process toward having the massive booster send astronauts to destinations that potentially include an asteroid towed into lunar orbit – and the planet Mars.

The SRB, known as Qualification Motor – 1 (QM-1), was built by Alliant Techsystems (ATK ), and is an upgraded five-segment version of the four-segment boosters used to assist the Space Shuttle to orbit. Two of these five segment boosters, along with four shuttle heritage RS-25 liquid fueled engines, will be used to power the SLS.

QM-1 has been installed, horizontally, in a specially built stand, located at ATK’s Promontory, Utah, test facility. This test version of the booster is 154 feet in length and 12 feet in diameter. The flight versions will be approximately 177 feet in length.

“What’s impressive about this test is when ignited, the booster will be operating at about 3.6 million pounds of thrust, or 22 million horsepower,” said Alex Priskos, manager of the SLS Boosters Office at Marshall. “This test firing is critical to enable validation of our design.”

Both QM-1, and later flight versions, are expected to produce this same 3.6 million pounds of thrust.

SLS booster segment as seen on Spaceflight Insider

The final segment of the full-scale version of a five-segment solid rocket motor for NASA’s new rocket, the Space Launch System, completed preparations Dec. 15 at ATK’s facility in Promontory, Utah. Photo Credit: ATK

The test is currently scheduled to take place at 9:30 a.m. (MST) and, if everything goes to plan, it should last for two minutes. That’s a bit less than the time the SRB will fire when it assists the SLS in getting off of Kennedy Space Center’s Launch Complex 39B in Florida.

“With RS-25 engine testing underway, and this qualification booster firing coming up, we are taking big steps toward building this rocket and fulfilling NASA’s mission of Mars and beyond,” said SLS Program Manager Todd May. “This is the most advanced propulsion system ever built and will power this rocket to places we’ve never reached in the history of human spaceflight.”

During the test, 103 different design objectives will be measured across 534 booster instrumentation channels. To help ensure the booster will meet structural and ballistic requirements, the booster will be subjected to temperatures of 90 degrees Fahrenheit (32 degrees Celsius) to measure its performance at high temperatures.

“Testing before flight is critical to ensure reliability and safety when launching crew into space,” said Charlie Precourt, vice president and general manager of ATK’s Space Launch division. “The QM-1 static test is an important step in further qualifying this new five-segment solid rocket motor for the subsequent planned missions to send astronauts to deep space.”

SSME Space Shuttle Main Engine Stennis Space Center RS-25 NASA image posted on SpaceFlight Insider

An RS-25 SSME undergoing testing. Four RS-25 engines will power the SLS.  Photo Credit: Aerojet Rocketdyne

Data will be collected on key motor upgrades, including the new insulation and booster case liner, as well as the redesigned nozzle. These improvements will ensure the SLS boosters are will be safe, affordable, and eco-friendly.

“While we made modifications to our booster for NASA’s new SLS, during the 30 years of the Space Shuttle Program, we also constantly monitored and improved our design,” said Precourt, a four-time space shuttle astronaut.

Booster hardware and software is developed, built and tested by ATK. Together with NASA, ATK has already successfully completed three, full-scale development test firings of the five-segment booster ahead of the March 11 test.

Stay tuned to SpaceFlight Insider for continuing updates on SLS development.

Also, be sure to tune into SpaceFlight Insider on March 11 as we will be on-site, in Utah, and streaming the entire event live!


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Scott earned both a Bachelor's Degree in public administration, and a law degree, from Samford University in Birmingham, Alabama. He currently practices law in the Birmingham suburb of Homewood. Scott first remembers visiting Marshall Space Flight Center in 1978 to get an up-close look at the first orbiter, Enterprise, which had been transported to Huntsville for dynamic testing. More recently, in 2006, he participated in an effort at the United States Space and Rocket Center (USSRC) to restore the long-neglected Skylab 1-G Trainer. This led to a volunteer position, with the USSRC curator, where he worked for several years maintaining exhibits and archival material, including flown space hardware. Scott attended the STS - 110, 116 and 135 shuttle launches, along with Ares I-X, Atlas V MSL and Delta IV NROL-15 launches. More recently, he covered the Atlas V SBIRS GEO-2 and MAVEN launches, along with the Antares ORB-1, SpaceX CRS-3, and Orion EFT-1 launches.

Reader Comments

Daniel Wisehart

Do the SRBs have a steerable nozzle like the shuttle SRBs did? I know that in his book, Chris Kraft, said he was not too fond of them and he thought they were unnecessary.

Yes, the SLS SRB’s will have a thrust vector control (TVC) system that will steer the nozzle. The TVC is currently in development / qualification at Marshall Space Flight Center (MSFC).

Are there opportunities for the public to view the rocket test firing at the Promontory, UT facility? I have found press opportunities, but have not found any mention of designated public viewing areas where interested publics could view the event.

Wow! Would there be a place were we could come to observe? We are a nearby school and would love to witness such an event. If it’s possible let us know where would be a good place to park. We have about 70 students from grades 7 & 8.

I would also like to know if it is possible for students to attend.

Zeke Villarreal

There is a location for the public to view. Here’s the information:
Public Viewing Area info:

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