# Agena D

> American rocket upper stage

**Wikidata**: [Q9142003](https://www.wikidata.org/wiki/Q9142003)  
**Source**: https://4ort.xyz/entity/agena-d

## Summary
The Agena D is an American rocket upper stage manufactured by the Lockheed Corporation. It functions as a space tug, designed to move payloads from a reference orbit to a target orbit or direct them toward an interplanetary trajectory. It is a specific model within the RM-81 Agena family and is powered by the Bell Model 8096 engine.

## Key Facts
- **Classification:** The Agena D is a rocket model and a subclass of the RM-81 Agena.
- **Function:** It serves as a space tug, a vehicle designed to move payloads to target orbits or interplanetary trajectories.
- **Manufacturer:** It was produced by the Lockheed Corporation.
- **Country of Origin:** United States.
- **Power Source:** The vehicle is powered by the Bell Model 8096 engine.
- **Related Entity:** It is the basis for the Agena Target Vehicle, a modified version used as a test target in Project Gemini missions.
- **Google Knowledge Graph ID:** /g/120phtjm.

## FAQs
### Q: What was the primary function of the Agena D?
A: The Agena D functioned as a rocket upper stage and a space tug. It was designed to transport payloads from a reference orbit to a specific target orbit or to set them on an interplanetary trajectory.

### Q: Who manufactured the Agena D?
A: The Agena D was manufactured by the American aerospace company Lockheed Corporation.

### Q: How is the Agena D related to Project Gemini?
A: The Agena D platform was modified to create the Agena Target Vehicle. This modified rocket was used by NASA as a test and training target during the Project Gemini missions.

### Q: What engine powered the Agena D?
A: The Agena D was powered by the Bell Model 8096 engine.

## Why It Matters
The Agena D represents a critical component of early American space infrastructure, serving as a versatile and reliable upper stage rocket. Its primary significance lies in its role as a "space tug," a specialized vehicle capable of maneuvering payloads once they have reached space. Unlike static upper stages that merely provide initial thrust, the Agena D was designed to move payloads from a reference orbit to a precise target orbit or redirect them toward interplanetary trajectories. This capability was essential for complex mission profiles requiring orbital adjustment and deep-space insertion.

Furthermore, the Agena D design proved adaptable for high-profile human spaceflight programs. It served as the technological foundation for the Agena Target Vehicle, which was utilized in Project Gemini. This modification allowed the Agena D to play a pivotal role in testing and training for orbital rendezvous and docking procedures. Manufactured by the Lockheed Corporation and powered by the Bell Model 8096 engine, the Agena D exemplifies the modular and reusable engineering approaches of the RM-81 Agena family.

## Notable For
- **Role as a Space Tug:** Distinguished by its specific capability to maneuver payloads between orbits or toward interplanetary paths.
- **Project Gemini Integration:** Serving as the platform for the Agena Target Vehicle, facilitating critical docking tests.
- **Bell Model 8096 Propulsion:** Utilization of this specific engine model to drive its upper stage operations.
- **RM-81 Agena Lineage:** Being a standardized model within the wider RM-81 Agena rocket family.

## Body
### Classification and Manufacture
The Agena D is an American rocket upper stage classified as a specific model of the broader RM-81 Agena family. It is also categorized functionally as a space tug. The vehicle was manufactured by the Lockheed Corporation in the United States. Its design and production contributed significantly to the United States' space capabilities during its operational era.

### Technical Specifications
The Agena D is an instance of a rocket model. A key technical component of the vehicle is its propulsion system. The Agena D is powered by the Bell Model 8096 engine. This engine enabled the vehicle to perform the precise maneuvers required for its role as an orbital transfer vehicle.

### Operational Role
As a space tug, the Agena D was designed to fulfill a specific logistical role in spaceflight. Its primary objective was to interact with payloads after an initial launch phase. The vehicle was engineered to move a payload from a reference orbit to a designated target orbit. Additionally, it had the capability to direct payloads onto an interplanetary trajectory, extending its utility beyond Earth's immediate orbit.

### Variants and Relations
A notable variant derived from the Agena D is the Agena Target Vehicle. This entity is described as a modified Agena-D rocket. It was utilized specifically as a test and training target during NASA's Project Gemini missions. This relationship highlights the adaptability of the Agena D design for both unmanned orbital transfer and manned spaceflight training support.