Bring the Heat! Watch NASA’s Full-Scale Space Launch System Rocket Booster Test

A livestream of the FSB-2 test is being made available at the NASA Marshall Space Flight Center YouTube page, which we’ve added above for your convenience. The test is also being broadcast as a Facebook Live on the SLS rocket’s Facebook page. Viewers are encouraged to submit questions on Twitter, Facebook, and YouTube using the hashtag #AskNASA. Experts from Northrop Grumman and Marshall Space Flight Center will be answering these questions.


It’s hard to believe, but the yet-to-be-launched SLS is indeed already in need of an upgrade. This is the result of several factors, including NASA’s chosen strategy of upgrading pre-existing technologies, ongoing delays, and budgetary constraints. Said Bruce Tiller, SLS Booster Program manager, in a NASA statement: “The current SLS boosters for the first eight Artemis missions are using a robust mix of new avionics and substantial heritage hardware from the Space Shuttle Program.” FSB-2 will “demonstrate some new materials, a completely new steering system, and a new way to ignite the motor,” he said, adding that the data derived from this test will “improve our booster design for future missions that take us farther into deep space than ever before.”

Image for article titled Watch Live as NASA Fires Up a New-and-Improved SLS Rocket Booster [Updated]
Graphic: NASA

During the test, the upgraded Flight Support Booster won’t be upright but will instead be placed horizontally onto a test stand. Controllers will fire the booster for approximately two minutes; it will blast for the same amount of time and with the same level of power that would be required during an actual liftoff of an SLS rocket.

That said, FSB-2 won’t mimic an exact flight configuration. SLS is also equipped with a pair of solid rocket boosters affixed to each side of the giant booster. The side boosters, also developed by Northrop Grumman, provide SLS with three-quarters of the total thrust during the first two minutes of flight.


The SLS booster consists of five 300,000-pound (136,000-kilogram) segments filled with fuel. The Space Shuttle’s booster was similar, though it had four segments. NASA says SLS solid rocket boosters “are the largest, most powerful boosters ever built for flight.” offers some background info on the booster:

These boosters were designed and built at the former Thiokol facility in Promontory. Via several name changes, splits, and merges, Northrop Grumman now owns the SRB [solid rocket booster] system. Thiokol won the contract to build the Space Shuttle’s solid rocket boosters on November 20, 1973, and the Promontory facility has been designing, building, and testing some version of the SRB design ever since.

During the Space Shuttle program, Thiokol and its successors routinely conducted static test firings of its solid rockets to test manufacturing process quality, changes, and booster modifications. This was part of ensuring the continued safety of flight for the Shuttles. Overall, 52 full-scale static firings of the Shuttle solid rocket boosters took place between July 1977 and February 2010.


Northrop Grumman continued these tests as part of the SLS program, running qualification tests of the five-segment booster in 2015 and 2015, according to

FSB-2 will add to the Flight Support Booster-1 (FSB-1) test performed in September 2020. Should all go well, today’s test will “demonstrate a newly qualified motor initiation system and qualify a new ablative lining to protect the booster nozzle,” according to NASA. What’s more, the test will help NASA in its plan to phase out the old (seems weird to write that) SLS booster and provision for the Artemis 9 mission and beyond.


The latest on Artemis 1—the inaugural launch of SLS—is that the rocket could finally fly as early as August 29. Windows for this historic launch are also available on September 2 and September 5.