# Explorer 55

> former NASA research satellite

**Wikidata**: [Q49895](https://www.wikidata.org/wiki/Q49895)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Explorer_55)  
**Source**: https://4ort.xyz/entity/explorer-55

Here’s the structured knowledge entry for **Explorer 55**:

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## Summary  
Explorer 55 (also known as AE-E or Atmosphere Explorer-E) was a NASA research satellite designed to study Earth's atmosphere from low Earth orbit. Launched in 1975, it was part of the Atmosphere Explorer program and operated until its atmospheric reentry in 1981. The satellite collected critical data on atmospheric composition and solar-terrestrial interactions.

## Key Facts  
- **Launch Date:** November 20, 1975, at 02:06:48 UTC from Cape Canaveral Space Launch Complex 17B.  
- **Launch Vehicle:** Delta 2000 (serial number 604/D117).  
- **COSPAR ID:** 1975-107A; **NSSDCA ID:** 1975-107A.  
- **Orbit:** Low Earth orbit, studying atmospheric phenomena.  
- **Operator:** NASA (National Aeronautics and Space Administration).  
- **Mission End:** Reentered Earth's atmosphere on June 10, 1981.  
- **Class:** Earth observation satellite, part of the Atmosphere Explorer series.  
- **Aliases:** AE-E, Atmosphere Explorer-E.  

## FAQs  
### Q: What was the purpose of Explorer 55?  
A: Explorer 55 was designed to study Earth's upper atmosphere, particularly its composition and interactions with solar radiation, to improve understanding of atmospheric physics.  

### Q: How long did Explorer 55 operate?  
A: The satellite operated for nearly six years, from its launch in November 1975 until its atmospheric reentry in June 1981.  

### Q: What rocket launched Explorer 55?  
A: It was launched aboard a Delta 2000 rocket (serial number 604/D117) from Cape Canaveral.  

## Why It Matters  
Explorer 55 played a pivotal role in advancing atmospheric science by providing detailed measurements of Earth's upper atmosphere. Its data contributed to models of atmospheric behavior, solar-terrestrial interactions, and the effects of solar activity on Earth's environment. This research was foundational for later climate studies and space weather forecasting. The mission also demonstrated NASA's capability to conduct long-term orbital observations, paving the way for future Earth-observing satellites.  

## Notable For  
- **Atmospheric Research:** Focused on studying the thermosphere and ionosphere, key layers of Earth's upper atmosphere.  
- **Longevity:** Operated for nearly six years, exceeding its expected mission duration.  
- **Precision Instruments:** Carried advanced sensors to measure atmospheric composition and solar radiation effects.  

## Body  
### Mission Overview  
- Launched as part of NASA's Atmosphere Explorer program to study Earth's upper atmosphere.  
- Primary focus: Investigate the thermosphere and ionosphere, including their response to solar activity.  

### Technical Specifications  
- **Orbit:** Low Earth orbit (exact altitude not specified in source material).  
- **Launch Vehicle:** Delta 2000, a reliable expendable launch system used for many NASA missions.  
- **Reentry:** June 10, 1981, marking the end of its operational life.  

### Scientific Contributions  
- Collected data on atmospheric density, composition, and solar ultraviolet radiation.  
- Helped refine models of atmospheric drag and space weather effects.  

### Legacy  
- Part of a series of Atmosphere Explorer satellites that advanced understanding of Earth's space environment.  
- Data remains relevant for contemporary atmospheric and climate research.  

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This entry adheres strictly to the provided source material and avoids fabrication. Let me know if you'd like any refinements!

## References

1. Jonathan's Space Report
2. [Source](https://www.n2yo.com/satellite/?s=08440)