Northrop Grumman Launches GEM 63XL - Longest Single-Segment Solid Rocket Boosters in Maiden Flight

In a development signaling advancements in the space launch industry, Northrop Grumman's GraphiteEpoxy Motor  (GEM) 63XL solid rocket boosters (SRBs) are set to make history as the longest single-segment motors ever flown.

The 72-foot monolithic SRB is slated to support the inaugural flight of United Launch Alliance's (ULA) Vulcan Centaur rocket on January 8th, boasting a length that surpasses its predecessor, the 66-foot GEM 63.

The manufacturing approach adopted by Northrop Grumman involves casting the GEM 63XL as a single piece, a technique aimed at enhancing reliability and efficiency by minimizing joints, hardware, and overall mass. With the capacity to deliver over 463,000 pounds of thrust, this becomes crucial for boosting the capabilities of rockets responsible for launching critical national payloads.

Utilizing digital engineering and virtual reality, the design and engineering teams immersed themselves into 360-degree virtual environments to examine life-size boosters.

The virtual reality approach allowed engineers to identify potential issues and make necessary design adjustments before entering the production phase. According to Kevin Foster, Chief Engineer of GEM 63/63XL at Northrop Grumman, this method enables the identification of issues that may not be apparent in a two-dimensional design, leading to time and cost savings.

Manufacturing the GEM 63XL monolithically provides several efficiency benefits, such as reducing hardware and overall mass, streamlining booster mating to the core vehicle, and enabling rapid launch cadence scheduling. The monolithic approach supports customer goals and provides benefits including a lighter, more cost-effective, and powerful booster.

Northrop Grumman has invested in increasing the depth of existing casting pits, incorporating dual casting, and modifying infrastructure to accommodate the larger GEM motors. Awarded a new ULA contract in 2022, Northrop Grumman plans to significantly increase GEM motor production rates, necessitating further expansion of solid rocket motor manufacturing facilities.