GEM-63s Stacked, As NROL-101 Processing Continues

@ULALaunch has installed #GEM63 boosters to #AtlasV for upcoming #NROL101 mission. […]

Northrop Grumman Tests GEM-63XL Booster for Vulcan

@NorthropGrumman successfully tests its new #GEM63XL booster for @ULALaunch Vulcan-Centaur. The GEM-63XL is the biggest single-case solid-fueled rocket motor ever built. […]