# Transit 4A
**Wikidata**: [Q9361178](https://www.wikidata.org/wiki/Q9361178)  
**Source**: https://4ort.xyz/entity/transit-4a

## Summary
Transit 4A is an artificial satellite utilized for both geodetic research and military purposes. Launched on June 29, 1961, it was deployed into orbit using a Thor-Ablestar rocket from Cape Canaveral. The spacecraft is identified by the COSPAR ID 1961-015A and the Harvard designation 1961 Omicron 1.

## Key Facts
- **COSPAR ID:** 1961-015A
- **Satellite Catalog Number (SCN):** 00116
- **Launch Date:** June 29, 1961
- **Launch Vehicle:** Thor-Ablestar (American expendable launch system)
- **Launch Site:** Cape Canaveral Space Launch Complex 17
- **Classifications:** Geodetic satellite and Military satellite
- **Harvard Designation:** 1961 Omicron 1
- **Significant Event:** Rocket launch on June 29, 1961
- **Wolfram Language Entity Code:** Entity["Satellite", "00116"]

## FAQs
### Q: What was the primary purpose of Transit 4A?
A: Transit 4A served a dual role as both a military satellite and a geodetic satellite. This means it was used for military applications as well as for the research and application of geodesy (measuring Earth's shape and size).

### Q: When and how was Transit 4A launched?
A: Transit 4A was launched on June 29, 1961. It was delivered to orbit by a Thor-Ablestar rocket launched from Cape Canaveral Space Launch Complex 17.

### Q: What are the unique identifiers for Transit 4A?
A: The satellite is identified internationally by the COSPAR ID 1961-015A and the Satellite Catalog Number 00116. It also holds the Harvard designation 1961 Omicron 1.

## Why It Matters
Transit 4A represents a notable entry in early space history, specifically illustrating the dual-use nature of satellite technology during the Cold War era. As a geodetic satellite, it played a role in the scientific research and application of geodesy, contributing to the precise measurement of the Earth's geometric shape, orientation in space, and gravitational field. Simultaneously, its classification as a military satellite underscores the strategic importance of space-based assets for national defense purposes during the early 1960s.

The mission is also significant for its use of the Thor-Ablestar launch vehicle, an American expendable launch system that was a critical component of early U.S. space infrastructure. The successful deployment of Transit 4A from Cape Canaveral on June 29, 1961, added to the operational capabilities of the Transit program. Furthermore, the assignment of the Harvard designation 1961 Omicron 1 highlights its formal recognition in astronomical and orbital catalogs.

## Notable For
- Being a dual-purpose **geodetic and military satellite**.
- Utilizing the **Thor-Ablestar** launch system.
- Being tracked under the unique Harvard designation **1961 Omicron 1**.
- Launching from the historic **Cape Canaveral Space Launch Complex 17**.

## Body
### Mission Profile and Launch
Transit 4A was successfully launched on **June 29, 1961**. The launch took place at **Cape Canaveral Space Launch Complex 17**. The vehicle used to propel the satellite into orbit was the **Thor-Ablestar**, an American expendable launch system. This event is cataloged as a significant rocket launch event in the satellite's history.

### Satellite Classification and Function
The spacecraft is defined by two primary classifications:
*   **Geodetic Satellite:** Used in the research and application of geodesy.
*   **Military Satellite:** An artificial satellite used for military purposes.

### Identification and Tracking
Transit 4A is cataloged in multiple scientific and tracking databases:
*   **Satellite Catalog Number (SCN):** 00116
*   **COSPAR International Designator:** 1961-015A
*   **Harvard Designation:** 1961 Omicron 1
*   **Wolfram Language Entity:** Entity["Satellite", "00116"]

## References

1. [Transit 4A. NASA Space Science Data Coordinated Archive](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1961-015A)
2. Jonathan's Space Report