Northrop Grumman validates new ULA rocket motor GEM 63XL rocket motors will help launch United Launch Alliance’s Vulcan Centaur rocket. United Launch Alliance (ULA) to provide additional lift capability to the Vulcan Centaur rocket. Charlie Precourt, vice president, propulsion systems, Northrop Grumman, said, “Evolving the original GEM 63 design utilizes our decades of GEM strap-on booster expertise while enhancing capabilities for heavy-lift missions.” During the static test, the motor fired for approximately 90 seconds, producing nearly 449,000 lb of thrust to validate the performance capability of the motor design. Additionally, this firing verified the motor’s internal insulation, propellant grain, ballistics, and nozzle in a hot-conditioned environment.