# SECOR 4

> American military geodetic satellite

**Wikidata**: [Q9326067](https://www.wikidata.org/wiki/Q9326067)  
**Source**: https://4ort.xyz/entity/secor-4

## Summary
SECOR 4 is an American military geodetic satellite launched on April 3, 1965, as part of the SECOR (Sequential Collation of Range) program. It was designed to support precise geodetic measurements and was operated by the United States Army Corps of Engineers. The satellite had a mass of 17.6 kilograms and dimensions of 34.9 cm (length) × 29.8 cm (width) × 25.2 cm (height).

## Key Facts
- **Launch Date**: April 3, 1965, at 21:25 UTC from Vandenberg Space Launch Complex 4 East.
- **Mass**: 17.6 kilograms.
- **Dimensions**: 34.9 cm (length) × 29.8 cm (width) × 25.2 cm (height).
- **Launch Vehicle**: Atlas SLV-3 Agena-D.
- **Manufacturer**: Cubic Corporation.
- **Orbit**: Low Earth orbit.
- **Sponsors**: United States Army and United States Air Force.
- **Operator**: United States Army Corps of Engineers.
- **Aliases**: Sequential Collation of Range 4, EGRS 4.
- **Part of**: SECOR program.

## FAQs
### Q: What was the purpose of SECOR 4?
A: SECOR 4 was a military geodetic satellite designed to support precise geodetic measurements, likely for military applications such as navigation and positioning.

### Q: Who launched SECOR 4?
A: SECOR 4 was launched by the United States Army and United States Air Force, with the United States Army Corps of Engineers operating the satellite.

### Q: What were the dimensions of SECOR 4?
A: SECOR 4 had dimensions of 34.9 cm (length) × 29.8 cm (width) × 25.2 cm (height).

### Q: What was the launch vehicle for SECOR 4?
A: SECOR 4 was launched using the Atlas SLV-3 Agena-D launch vehicle.

### Q: Where was SECOR 4 launched from?
A: SECOR 4 was launched from Vandenberg Space Launch Complex 4 East on April 3, 1965.

## Why It Matters
SECOR 4 was part of the SECOR program, which aimed to provide a global satellite-based navigation system for military use. Geodetic satellites like SECOR 4 were crucial for precise positioning and mapping, supporting operations such as missile tracking and strategic defense. The program contributed to the development of early satellite navigation technologies, laying the groundwork for future military and civilian satellite-based positioning systems. SECOR 4's successful deployment demonstrated the feasibility of using satellites for geodetic measurements, paving the way for more advanced systems in the future.

## Notable For
- **Military Geodesy**: SECOR 4 was one of the first satellites dedicated to military geodetic measurements, supporting precise positioning for defense applications.
- **Atlas SLV-3 Agena-D Launch**: The satellite was launched using the Atlas SLV-3 Agena-D, a reliable and versatile launch vehicle for military satellites.
- **Low Earth Orbit Operations**: SECOR 4 operated in low Earth orbit, providing critical data for geodetic research and military navigation.
- **Cubic Corporation Manufacturing**: The satellite was manufactured by Cubic Corporation, which played a key role in producing early military satellites.
- **Vandenberg Launch Site**: The launch from Vandenberg Space Launch Complex 4 East was significant for the U.S. military's space operations.

## Body
### Overview
SECOR 4 was a military geodetic satellite launched on April 3, 1965, as part of the SECOR program. The satellite was designed to support precise geodetic measurements, likely for military applications such as navigation and positioning. It had a mass of 17.6 kilograms and dimensions of 34.9 cm (length) × 29.8 cm (width) × 25.2 cm (height).

### Launch and Deployment
SECOR 4 was launched from Vandenberg Space Launch Complex 4 East using the Atlas SLV-3 Agena-D launch vehicle. The launch occurred at 21:25 UTC on April 3, 1965. The satellite was operated by the United States Army Corps of Engineers, with sponsorship from the United States Army and United States Air Force.

### Technical Specifications
- **Mass**: 17.6 kilograms.
- **Dimensions**: 34.9 cm (length) × 29.8 cm (width) × 25.2 cm (height).
- **Orbit**: Low Earth orbit.
- **Manufacturer**: Cubic Corporation.

### Significance
SECOR 4 was part of the SECOR program, which aimed to provide a global satellite-based navigation system for military use. The program contributed to the development of early satellite navigation technologies, supporting operations such as missile tracking and strategic defense. SECOR 4's successful deployment demonstrated the feasibility of using satellites for geodetic measurements, paving the way for more advanced systems in the future.

## References

1. [Source](https://space.skyrocket.de/doc_sdat/secor-1.htm)
2. Jonathan's Space Report