The GEM 63XL motor being prepared for static test firing in a Test Area test bay. Photo: Northrop Grumman

Northrop Grumman conducted its first ground test of an extended length 63-inch-diameter Graphite Epoxy Motor (GEM 63XL) in Promontory, Utah on Thursday. This variation of the company’s GEM 63 strap-on booster was developed in partnership with United Launch Alliance (ULA) to provide additional lift capability to the Vulcan Centaur vehicle.

The motor fired for approximately 90 seconds during the static test, producing nearly 449,000 lbs of thrust to qualify the motor’s internal insulation, propellant grain, ballistics, and nozzle in a cold-conditioned environment. This test demonstrated materials and technologies similar to the GEM 63 rocket motor that qualified for flight in October 2019.

“Our new GEM 63XL motors leverage its flight-proven heritage while utilizing state-of-the-art manufacturing technology to enhance launch vehicle heavy-lift capabilities,” said Charlie Precourt, vice president, propulsion systems, Northrop Grumman. “The GEM 63XL increases thrust and performance by 15-20 percent compared to a standard GEM 63.”