# Atlas SLV-3A Agena-D

> type of American expendable launch vehicle

**Wikidata**: [Q99672687](https://www.wikidata.org/wiki/Q99672687)  
**Source**: https://4ort.xyz/entity/atlas-slv-3a-agena-d

## Summary
Atlas SLV-3A Agena-D is an American expendable launch vehicle, specifically a rocket model within the Atlas-Agena D class. It combined an Atlas SLV-3 first stage with an Agena D upper stage to carry satellites into orbit from 1968 to 1978.

## Key Facts
- **Instance of**: Rocket model  
- **Subclass of**: Atlas-Agena D (expendable launch system)  
- **Has parts**: Atlas SLV-3 first stage and Agena D upper stage  
- **First flight**: March 4, 1968  
- **Service retirement**: April 8, 1978  
- **Manufacturer**: Convair  
- **Country of origin**: United States  
- **Launch class**: Expendable launch vehicle  
- **Service duration**: 10 years (1968–1978)  

## FAQs  
### Q: What payloads did Atlas SLV-3A Agena-D typically carry?  
A: It was designed for satellite deployments, supporting scientific and research missions. Notably, it launched OGO 5, an American geophysical research satellite.  

### Q: How does Atlas SLV-3A Agena-D differ from other Atlas-Agena models?  
A: It is a specific rocket model variant within the Atlas-Agena D class, distinct from other Atlas configurations by its use of the SLV-3 stage and Agena D components.  

### Q: Why was Atlas SLV-3A Agena-D retired in 1978?  
A: No explicit reason is provided in the source material, but its retirement marked the end of its operational service after a decade of use.  

## Why It Matters  
Atlas SLV-3A Agena-D represented a key component of the U.S. space program’s launch infrastructure during the late 20th century. As a standardized expendable vehicle, it enabled routine satellite deployments for scientific research, including the OGO 5 geophysical mission. Its 10-year operational span underscored its reliability in supporting space exploration efforts, though it was eventually phased out as newer launch technologies emerged.  

## Notable For  
- **Long operational service**: Active for 10 years (1968–1978), demonstrating sustained use in the U.S. launch fleet.  
- **Part of Atlas-Agena legacy**: A distinct model within the Atlas-Agena D family, which formed a cornerstone of American orbital launch capabilities.  
- **Scientific mission support**: Enabled satellite launches for research, as evidenced by its relation to the OGO 5 geophysical satellite.  

## Body  
### Overview  
Atlas SLV-3A Agena-D is a type of American expendable launch vehicle classified as a rocket model. It belongs to the Atlas-Agena D class, which encompasses expendable launch systems for orbital missions. The vehicle combined modular components to serve as a dedicated satellite deployment platform.  

### Components  
The launch system integrated two primary sections:  
- **Atlas SLV-3 first stage**: Provided initial thrust during ascent.  
- **Agena D upper stage**: Executed orbital insertion and payload deployment.  

### Service History  
- **First flight**: March 4, 1968.  
- **Service retirement**: April 8, 1978.  
- **Duration**: Operated continuously for 10 years, emphasizing its role in routine space missions.  

### Manufacturer and Origin  
- Built by Convair, a U.S. aerospace manufacturer.  
- Developed under the United States as its country of origin, aligning with Cold War-era space program priorities.