Graphite-Epoxy Motor
A GEM 40 solid rocket motor being prepared for integration with a Delta II launch vehicle | |
| Manufacturer |
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|---|---|
| Country of origin | United States |
| Used on | |
| Associated stages | |
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| Launch history | |
| Status | Active |
| First flight | 26 November 1990 |
The Graphite-Epoxy Motor (GEM) is a family of solid rocket boosters developed in the late 1980s and used since 1990. GEM motors are manufactured with carbon-fibre-reinforced polymer casings and a fuel consisting of HTPB-bound ammonium perchlorate composite propellant. GEM is produced by Northrop Grumman Space Systems. GEM boosters are used on the Atlas V and were previously used on the Delta II, Delta III, and Delta IV launch vehicles. A new variant, the GEM 63XL, flew as part of the Vulcan Centaur launch vehicle on 8 January 2024.