# Extreme Ultraviolet Explorer

> NASA space telescope for ultraviolet astronomy

**Wikidata**: [Q49904](https://www.wikidata.org/wiki/Q49904)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Extreme_Ultraviolet_Explorer)  
**Source**: https://4ort.xyz/entity/extreme-ultraviolet-explorer

## Summary
The **Extreme Ultraviolet Explorer (EUVE)** was a NASA space telescope launched in 1992 to study ultraviolet astronomy, specifically the extreme ultraviolet (EUV) spectrum. It was part of NASA's Explorers Program and operated until its decommissioning in 2001, contributing significantly to the understanding of celestial objects in the EUV range.

## Key Facts
- Launched on **June 7, 1992**, from **Cape Canaveral Space Launch Complex 17A** aboard a **Delta II** rocket.
- Operated as part of NASA's **Explorers Program** (Explorer 67).
- Decommissioned on **January 31, 2001**, and re-entered Earth's atmosphere on **January 30, 2002**.
- Also known by aliases **EUVE** and **Explorer 67**.
- Followed the **Cosmic Background Explorer (COBE)** and preceded the **Solar Anomalous and Magnetospheric Particle Explorer (SAMPEX)**.
- Used the **Multi-Mission Modular Spacecraft (MMS)** bus design.
- Official website: [http://www.ssl.berkeley.edu/euve/](http://www.ssl.berkeley.edu/euve/) (archived).

## FAQs
### Q: What was the purpose of the Extreme Ultraviolet Explorer?
A: The EUVE was designed to observe celestial objects in the extreme ultraviolet (EUV) spectrum, providing data on stars, galaxies, and other astronomical phenomena in this wavelength range.

### Q: When was the EUVE launched and decommissioned?
A: It was launched on **June 7, 1992**, and decommissioned on **January 31, 2001**, with atmospheric re-entry occurring on **January 30, 2002**.

### Q: What rocket launched the EUVE?
A: The EUVE was launched using a **Delta II** rocket (model D210) from **Cape Canaveral Space Launch Complex 17A**.

### Q: What program was the EUVE part of?
A: It was part of NASA's **Explorers Program**, specifically designated as **Explorer 67**.

### Q: What happened to the EUVE after decommissioning?
A: After decommissioning, the spacecraft remained in orbit until it re-entered Earth's atmosphere on **January 30, 2002**.

## Why It Matters
The Extreme Ultraviolet Explorer played a crucial role in advancing ultraviolet astronomy by providing the first comprehensive survey of the sky in the extreme ultraviolet (EUV) spectrum. Before EUVE, this wavelength range was poorly studied due to atmospheric absorption, which blocks EUV light from reaching ground-based telescopes. By operating in space, EUVE enabled astronomers to observe hot stellar objects, white dwarfs, active galaxies, and other high-energy phenomena. Its observations helped refine models of stellar evolution, interstellar medium composition, and the behavior of plasma in extreme environments. The mission also demonstrated the feasibility of long-duration EUV observations, paving the way for future ultraviolet and X-ray observatories.

## Notable For
- **First space telescope dedicated to extreme ultraviolet astronomy**, filling a critical gap in astronomical observations.
- **Conducted the first all-sky survey in the EUV spectrum**, cataloging hundreds of EUV sources.
- **Operated for nearly a decade**, from 1992 to 2001, exceeding its planned mission lifetime.
- **Part of NASA's Explorers Program**, a series of cost-effective, focused scientific missions.
- **Used the Multi-Mission Modular Spacecraft (MMS) bus**, a versatile platform for multiple NASA missions.

## Body
### Mission Overview
The **Extreme Ultraviolet Explorer (EUVE)** was a NASA space telescope designed to observe the universe in the extreme ultraviolet (EUV) wavelength range (approximately 7–76 nm). This spectrum is largely absorbed by Earth's atmosphere, making space-based observation essential.

### Launch and Orbit
- **Launch Date:** June 7, 1992, at 16:40 UTC.
- **Launch Vehicle:** Delta II (D210 variant).
- **Launch Site:** Cape Canaveral Space Launch Complex 17A.
- **Orbit:** Low Earth orbit (LEO), circular at ~500 km altitude.

### Spacecraft Design
- **Spacecraft Bus:** Multi-Mission Modular Spacecraft (MMS), developed by Fairchild Space.
- **Instruments:** Included EUV spectrometers and imagers to detect and analyze EUV emissions.
- **Mass:** ~3,200 kg (including fuel).

### Mission Timeline
- **1992–1993:** All-sky survey phase, mapping EUV sources.
- **1993–2001:** Pointed observations of specific targets, including stars, galaxies, and interstellar medium studies.
- **January 31, 2001:** Decommissioned after completing its scientific objectives.
- **January 30, 2002:** Re-entered Earth's atmosphere, ending its operational life.

### Scientific Contributions
- **Discovered new EUV sources**, including white dwarfs, active stars, and cataclysmic variables.
- **Studied the interstellar medium**, revealing how EUV light is absorbed and scattered.
- **Provided data on stellar coronas**, helping astronomers understand the outer atmospheres of stars.
- **Supported follow-up missions** by identifying targets for later UV and X-ray observatories.

### Legacy
The EUVE mission demonstrated the importance of EUV astronomy and influenced the design of subsequent space telescopes, such as the **Far Ultraviolet Spectroscopic Explorer (FUSE)** and **Galaxy Evolution Explorer (GALEX)**. Its data remains valuable for studying high-energy astrophysical processes.

## Schema Markup
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  "name": "Extreme Ultraviolet Explorer",
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## References

1. Virtual International Authority File
2. Jonathan's Space Report
3. Freebase Data Dumps. 2013
4. [Source](https://space.skyrocket.de/doc_sat/fairchild_mms.htm)
5. [Source](https://www.n2yo.com/satellite/?s=21987)