NASA Set to "Hot Fire" Its Space Launch System Core Stage

NASA unveiled its plans for the final test in its Space Launch System's (SLS) Green Run series, the "hot fire," and the agency is looking for a January 17 test run.

Hot fire, according to the space agency, is the last in the eight-part Green Run test campaign that will bring the core stage of the SLS to life. Described as the Space Launch System is NASA's next deep-space rocket program that will power future space exploration plans, including the Artemis program.

Culminating the Green Run Series

The hot fire test follows the seventh part of the Green Run, the wet dress rehearsal.

Conducted last December 20 at the Stennis Space Center, located near Bay St. Louis in Mississippi, the rehearsal stage marks the first instance of the liquid propellant - 700,000 gallons of super cold, or cryogenic, fuel mixture - was fully loaded onto the dual tanks of the SLS core stage and was drained after without igniting the engine.

In the wet dress rehearsal, development teams assess the core stage's cryogenic storage capabilities through environmental and structural information, test software response with flight computers and avionics, and functional checks of all core stage systems. During the test, the rehearsal had to be stopped automatically, a few minutes earlier than projected because of a valve closure timing discrepancy. However, looking at the data showed that the valve was only off by a fraction of a second with all other parts of the core stage performing properly to stop the rehearsal. After correcting the timing, the SLS core stage is now greenlit for the hot fire.

The hot fire, like its predecessor, will be conducted at the NASA Stennis Space Center.

The Green Run series begins with the application of forces that simulate launch to an unpowered and suspended core stage before turning the systems on for an assessment of avionics in the SLS core stage. Next, potential issues are simulated to check the core stage response in shutting down related systems in the event of a problem.

At the fourth stage, the main propulsion systems connected to the engines are tested, followed by thrust vector tests for instrumentation and hydraulic systems compliance. Then, launch countdown simulation is conducted, to verify timeline projections and operation sequences - then the wet dress rehearsal is conducted.

The SLS Core Stage

Once the hot fire commences, it will mark the ignition of the most powerful rocket on the planet. Standing at about 322 feet high (98 meters), While it falls short of Saturn V's impressive 363-feet height, the SLS promises up to 15 percent more thrust during liftoff and ascent. But until the SLS is moved to operational status, Saturn V retains the records for being the tallest, heaviest, and most powerful rocket in space exploration history.

The core stage serves as the backbone of the SLS, containing the main propulsion system and fuelling the rocket engines at the base. It was fabricated at the Michoud Assembly Facility, a NASA location in New Orleans.