Northrop Grumman’s first ground test of its GEM 63 rocket motor. Photo: Northrop Grumman

Northrop Grumman conducted its first ground test of a 63-inch diameter Graphite Epoxy Motor (GEM 63) yesterday in Promontory, Utah. Utilizing advanced technologies, the company developed this new rocket motor for use on the United Launch Alliance (ULA) Atlas V launch vehicle.

Northrop Grumman began developing the motor three years ago. The GEM 63 motor will be used as a direct replacement of the previous strap-on boosters on ULA’s Atlas V rocket beginning in July 2019 with the Space Test Program (STP)-3 mission that will use five boosters. Additional missions will follow, each of which may include up to five solid rocket motors.

Northrop Grumman is also developing a GEM 63XL motor using internal funding for use on ULA’s Vulcan Centaur rocket, which will fly with up to six GEM 63XLs per flight. The first GEM 63XL case, which is the longest non-segmented, monolithic case ever manufactured, has already been wound at a new facility in Clearfield, Utah. The next GEM 63 motor test, scheduled for November, will satisfy additional requirements for certification by the U.S. Air Force.