# ESSA-4

> former American weather satellite

**Wikidata**: [Q16325199](https://www.wikidata.org/wiki/Q16325199)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/ESSA-4)  
**Source**: https://4ort.xyz/entity/essa-4

## Summary
ESSA-4 was a former American weather satellite launched on January 26, 1967, as part of the TIROS Operational System. It was designed to monitor weather and climate, operating in a sun-synchronous orbit before being decommissioned in May 1968.

## Key Facts
- **Type**: Weather satellite (decommissioned)
- **Launch Date**: January 26, 1967, at 17:31 UTC
- **Launch Site**: Vandenberg Space Launch Complex 2 East
- **Launch Vehicle**: Delta E (Thor 472/D-045)
- **Operator**: Environmental Science Services Administration (ESSA)
- **Mass**: 286 kilograms
- **Dimensions**: 56 cm height, 107 cm diameter
- **Orbit**: Sun-synchronous orbit
- **Power Source**: Spacecraft solar array (solar cells) and nickel–cadmium battery (21 units)
- **Manufacturer**: RCA Corporation
- **Country of Origin**: United States
- **Predecessor**: ESSA-3
- **Successor**: ESSA-5
- **Significant Events**: Hibernation in December 1967, service retirement in May 1968

## FAQs
### Q: What was ESSA-4's primary purpose?
A: ESSA-4 was a weather satellite designed to monitor weather and climate, operating in a sun-synchronous orbit to provide continuous data for forecasting and research.

### Q: Who operated ESSA-4?
A: The satellite was operated by the Environmental Science Services Administration (ESSA), a U.S. government agency.

### Q: How long did ESSA-4 remain operational?
A: ESSA-4 was decommissioned in May 1968, having been launched in January 1967.

### Q: What was unique about ESSA-4's power system?
A: ESSA-4 was powered by a spacecraft solar array with solar cells and a nickel–cadmium battery, totaling 21 units.

### Q: What was ESSA-4's relationship to other satellites in the TIROS Operational System?
A: ESSA-4 followed ESSA-3 and preceded ESSA-5 within the TIROS Operational System, a series of American meteorological satellites.

## Why It Matters
ESSA-4 played a crucial role in the early development of weather satellite technology, contributing to the TIROS Operational System. As part of the U.S. weather monitoring network, it provided essential data for climate research and forecasting. Its launch and operation marked a significant step in the evolution of satellite-based meteorology, helping to establish a reliable system for tracking weather patterns and environmental conditions. The satellite's decommissioning in 1968 reflected the ongoing advancements in space technology, paving the way for more advanced weather satellites in subsequent decades.

## Notable For
- **Part of the TIROS Operational System**: ESSA-4 was a key component of the TIROS Operational System, a model of American meteorological satellites.
- **Sun-Synchronous Orbit**: Its orbit allowed for consistent data collection, aiding in long-term climate monitoring.
- **Decommissioned in 1968**: ESSA-4 was retired shortly after launch, marking an early phase in the lifecycle of weather satellites.
- **Powered by Solar and Battery**: Its hybrid power system was innovative for its time, ensuring reliable operation in space.
- **Preceded and Succeeded by Other Satellites**: ESSA-4 was part of a series, with ESSA-3 and ESSA-5 as its immediate predecessors and successors.

## Body
### Overview
ESSA-4 was a weather satellite launched by the United States on January 26, 1967, as part of the TIROS Operational System. It was designed to monitor weather and climate, operating in a sun-synchronous orbit to ensure continuous data collection. The satellite was operated by the Environmental Science Services Administration (ESSA) and was manufactured by RCA Corporation.

### Technical Specifications
- **Mass**: 286 kilograms
- **Dimensions**: 56 cm in height and 107 cm in diameter
- **Power System**: Equipped with a spacecraft solar array using solar cells and a nickel–cadmium battery, totaling 21 units
- **Orbit**: Sun-synchronous orbit

### Launch and Operation
- **Launch Date**: January 26, 1967, at 17:31 UTC
- **Launch Site**: Vandenberg Space Launch Complex 2 East
- **Launch Vehicle**: Delta E (Thor 472/D-045)
- **Significant Events**: Entered hibernation on December 6, 1967, and was decommissioned on May 5, 1968

### Relationship to Other Satellites
- **Predecessor**: ESSA-3
- **Successor**: ESSA-5
- **Part of**: TIROS Operational System

### Identifiers
- **COSPAR ID**: 1967-006A
- **NSSDCA ID**: 1967-006A
- **SCN**: 02657

## Schema Markup
```json
{
  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "ESSA-4",
  "description": "Former American weather satellite launched in 1967 as part of the TIROS Operational System.",
  "sameAs": [
    "https://www.wikidata.org/wiki/Q6272367",
    "https://en.wikipedia.org/wiki/ESSA-4"
  ],
  "additionalType": "WeatherSatellite"
}

## References

1. [Source](https://space.skyrocket.de/doc_sdat/essa.htm)
2. Jonathan's Space Report
3. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1967-006A)
4. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1966-016A)