GEM 40
GEM 40 is a 40-inch composite-case booster for Delta II. Fixed-nozzle ground- and air-ignited configurations differ in nozzle expansion and insulation. A separate GEM 40VN configuration uses thrust-vector control. The fixed-nozzle catalogue burn time is 63.3 s.
Identity
- Domains
- spaceflight
- Identity Level
- variant
- Kind
- solid-rocket-motor
- Name
- GEM 40
- Status
- retired
Details
- Description
- GEM 40 is a 40-inch composite-case booster for Delta II. Fixed-nozzle ground- and air-ignited configurations differ in nozzle expansion and insulation. A separate GEM 40VN configuration uses thrust-vector control. The fixed-nozzle catalogue burn time is 63.3 s.
- Developers
- Family
- Manufacturers
- Propellants
- solid propellant
Links
Assets & Meta
- Creation Time
- August 1, 2026 at 10:28:50 UTC
- Updated Time
- October 29, 2026 at 15:55:46 UTC
Other
- Sources
- Accessed Date
- 2026-08-01
- Note
- Names ATK GEM-40 strap-on motors on Delta II.
- Publisher
- NASA
- Title
- Delta II Data Sheet
- Accessed Date
- 2026-08-01
- Note
- Describes up to nine 40-inch GEM solid rocket motors augmenting the Delta II first stage.
- Publisher
- NASA
- Title
- Routine Payloads Environmental Assessment
- Accessed Date
- 2026-08-01
- Note
- Identifies nine Alliant Techsystems strap-on solid rocket motors on Delta II 7925-10L.
- Publisher
- United Launch Alliance
- Title
- ULA Marks Delta II 20 Year Anniversary with Successful NASA Kepler Launch
- Accessed Date
- 2026-10-29
- Note
- GEM family overview and exact configuration pages distinguish ignition and nozzle alternatives; historical catalogue lifecycle checked against the 2025 sheet.
- Publisher
- Northrop Grumman
- Title
- GEM Motor Series — product catalogue