# ORFEUS-SPAS II

> free-flying observatory carried on Space Shuttle mission STS-80

**Wikidata**: [Q2007875](https://www.wikidata.org/wiki/Q2007875)  
**Source**: https://4ort.xyz/entity/orfeus-spas-ii

## Summary  
ORFEUS-SPAS II was a free-flying space observatory launched aboard NASA's Space Shuttle Columbia during mission STS-80 on November 19, 1996. It was designed to conduct astronomical observations in the far- and extreme-ultraviolet spectrum using the ORFEUS telescope. The mission marked the second flight of the ORFEUS-SPAS program, following ORFEUS-SPAS I.

## Key Facts  
- Launched on November 19, 1996 at 19:55:47 UTC from Kennedy Space Center Launch Complex 39B aboard Space Shuttle Columbia (mission STS-80)  
- Mass: 3,500 kg; Length: 2.5 m; Width: 4.5 m  
- Operated by the German Space Agency (DLR) and National Aeronautics and Space Administration (NASA)  
- Built by DASA (now Airbus Defence and Space) in Germany  
- COSPAR ID: 1996-065B; NSSDCA ID: 1996-065B  
- Carried the scientific instrument ORFEUS, a far- and extreme-ultraviolet spectrometer  
- Based on the Shuttle Pallet Satellite (SPAS) bus  
- Succeeded ORFEUS-SPAS I, which flew on STS-51  

## FAQs  
### Q: What was ORFEUS-SPAS II used for?  
A: ORFEUS-SPAS II was used to observe celestial objects in the far- and extreme-ultraviolet wavelengths, providing valuable data on stellar atmospheres and interstellar matter. It carried the ORFEUS telescope, specifically designed for high-resolution spectroscopy in this spectral range.

### Q: When was ORFEUS-SPAS II launched?  
A: ORFEUS-SPAS II was launched on November 19, 1996, at 19:55:47 UTC as part of Space Shuttle mission STS-80.

### Q: Who built and operated ORFEUS-SPAS II?  
A: The satellite was built by DASA in Germany and jointly operated by the German Space Agency (DLR) and NASA.

## Why It Matters  
ORFEUS-SPAS II played a critical role in advancing ultraviolet astronomy by enabling detailed spectroscopic observations of hot stars and the interstellar medium. Its deployment via the Space Shuttle allowed for retrieval and potential reuse, combining the benefits of both free-flyer and retrievable satellite missions. The mission contributed significantly to understanding astrophysical processes in the galaxy through its unique observational capabilities in the poorly explored extreme-ultraviolet regime. As part of the broader ORFEUS project, it also demonstrated international cooperation between European and American space agencies.

## Notable For  
- First free-flying payload dedicated entirely to far- and extreme-ultraviolet astronomy with high spectral resolution  
- Second mission in the ORFEUS-SPAS series, improving upon earlier instrumentation and techniques  
- Successful deployment and retrieval using the Space Shuttle system  
- Collaboration between German and U.S. space programs under the Shuttle pallet satellite framework  
- Enabled precise measurements of stellar winds and circumstellar environments previously inaccessible from ground-based telescopes  

## Body  
### Mission Overview  
ORFEUS-SPAS II was deployed during NASA’s STS-80 mission, flown by Space Shuttle Columbia. The mission lasted over 17 days, making it one of the longest Shuttle flights at that time. During the mission, the satellite conducted autonomous astronomical observations before being retrieved by the Shuttle crew.

### Design and Construction  
The spacecraft was based on the Shuttle Pallet Satellite (SPAS) platform, allowing it to be carried in the Shuttle cargo bay and released into orbit. It had a mass of approximately 3,500 kilograms and measured 2.5 meters in length and 4.5 meters in width. The primary instrument onboard was the ORFEUS telescope, optimized for far- and extreme-ultraviolet spectroscopy.

### Operators and Developers  
Developed by DASA (Deutsche Aerospace AG), now part of Airbus Defence and Space, the satellite was a product of German engineering expertise. Operations were shared between the German Space Agency (DLR) and NASA, reflecting strong transatlantic collaboration in space science.

### Scientific Payload  
The core payload, ORFEUS, consisted of three telescopes equipped with spectrographs operating in the wavelength range of 500–1200 Ångströms. These instruments enabled researchers to study hot stellar atmospheres, white dwarfs, and diffuse interstellar gas with unprecedented sensitivity in the extreme-ultraviolet band.

### Legacy and Impact  
Data collected during the ORFEUS-SPAS II mission contributed to numerous peer-reviewed studies in astrophysics. By extending observational capabilities beyond Earth’s atmosphere and atmospheric absorption limits, the mission helped refine models of stellar evolution and cosmic element production. It also paved the way for future UV space missions such as FUSE and GALEX.

## References

1. [Source](https://space.skyrocket.de/doc_sdat/orfeus-spas.htm)
2. Jonathan's Space Report
3. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1996-065B)