# Herschel Space Observatory

> former ESA space observatory

**Wikidata**: [Q209630](https://www.wikidata.org/wiki/Q209630)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Herschel_Space_Observatory)  
**Source**: https://4ort.xyz/entity/herschel-space-observatory

## Summary
The Herschel Space Observatory was a European Space Agency (ESA) space telescope launched in 2009 to study the universe in far-infrared and submillimeter wavelengths. It operated until 2013 when its liquid helium coolant was depleted, ending its scientific mission. The observatory was the largest infrared telescope ever launched into space at the time.

## Key Facts
- Launched on May 14, 2009, at 13:12:02 UTC from ELA-3 launch site
- Operated by the European Space Agency (ESA) with NASA participation
- Mass: 3,400 kilograms (launch weight)
- Dimensions: 4.0 meters wide × 7.5 meters tall
- Powered by 12 square meters of solar arrays and lithium-ion batteries
- Carried a 3.5-meter primary mirror, the largest infrared telescope in space at launch
- Operated in a Lissajous orbit around the L2 Earth-Sun Lagrangian point
- Mission ended on June 17, 2013, at 12:25 UTC when the spacecraft was retired
- Named after astronomers William and Caroline Herschel

## FAQs
### Q: What was the primary scientific goal of the Herschel Space Observatory?
A: Herschel was designed to observe the universe in far-infrared and submillimeter wavelengths, allowing it to study cold and dusty regions of space that are invisible to optical telescopes, including star formation, galaxy evolution, and the interstellar medium.

### Q: Why did the Herschel Space Observatory stop working?
A: The observatory's instruments required liquid helium cooling to operate at extremely low temperatures. When the helium supply was depleted on April 29, 2013, the instruments warmed up and could no longer make observations, leading to the mission's end.

### Q: Where was Herschel positioned in space?
A: Herschel operated in a Lissajous orbit around the L2 Lagrangian point, approximately 1.5 million kilometers from Earth in the direction away from the Sun, where it maintained a stable position relative to Earth and the Sun.

## Why It Matters
The Herschel Space Observatory represented a major leap forward in infrared astronomy, providing unprecedented sensitivity and resolution for studying the cold universe. Its 3.5-meter mirror made it the largest infrared telescope ever launched, allowing it to detect faint emissions from distant galaxies, star-forming regions, and planetary systems. The observatory's observations transformed our understanding of galaxy formation and evolution, revealing how stars and planets form within dusty clouds that block visible light. Herschel's data continues to be valuable for astronomers, with its vast archive enabling new discoveries years after the mission ended. The observatory demonstrated the importance of international collaboration in space science, with ESA leading the mission while NASA provided significant contributions to the instrumentation and data analysis.

## Notable For
- Largest infrared space telescope ever launched at the time, with a 3.5-meter primary mirror
- First space observatory to cover the full far-infrared and submillimeter wavelength range (55-672 microns)
- Discovered water in various cosmic environments, from comets to distant galaxies
- Provided the most detailed view of the cosmic infrared background, revealing hidden star formation in the early universe
- Operated for nearly four years beyond its planned mission duration, collecting over 35,000 scientific observations

## Body
### Technical Specifications
The Herschel Space Observatory featured a 3.5-meter primary mirror made of silicon carbide, the largest single mirror ever built for a space telescope at the time of launch. The telescope was cooled to approximately 80 Kelvin (-193°C) using superfluid liquid helium, while the focal plane units of its three scientific instruments were cooled to even lower temperatures of 0.3 Kelvin using helium-3 sorption coolers.

### Scientific Instruments
Herschel carried three main instruments: PACS (Photodetector Array Camera and Spectrometer) for imaging and spectroscopy, SPIRE (Spectral and Photometric Imaging Receiver) for photometry and spectroscopy, and HIFI (Heterodyne Instrument for the Far Infrared) for high-resolution spectroscopy. These instruments covered the wavelength range from 55 to 672 microns, allowing observations of cold gas and dust in the universe.

### Mission Operations
The observatory operated from July 21, 2009, when it began regular science operations, until April 29, 2013, when its helium coolant was depleted. During its mission, Herschel made over 35,000 scientific observations, producing more than 25,000 hours of science data. The spacecraft was launched together with the Planck satellite aboard an Ariane 5 ECA rocket (flight V188) from the Guiana Space Centre in French Guiana.

### Scientific Achievements
Herschel's observations revealed previously hidden aspects of the universe, including detailed views of star-forming regions in our galaxy, the discovery of water in various cosmic environments, and insights into galaxy formation and evolution in the early universe. The observatory detected thousands of distant galaxies and provided crucial data for understanding the cosmic infrared background radiation. Its observations of the interstellar medium helped astronomers understand the life cycle of matter in galaxies, from the formation of stars to the enrichment of the interstellar medium with heavy elements.

## References

1. [Source](https://science.nasa.gov/mission/herschel-space-observatory/)
2. [Source](https://sci.esa.int/web/planck/-/27524-esa-announces-signature-of-its-largest-ever-contract-awarded-to-build-astronomy-satellites)
3. Virtual International Authority File
4. Jonathan's Space Report
5. [Source](https://www.esa.int/Science_Exploration/Space_Science/Herschel/Vital_stats)
6. [Source](https://sci.esa.int/web/herschel/-/47356-fact-sheet)
7. Freebase Data Dumps. 2013
8. [Source](https://www.cosmos.esa.int/web/herschel/latest-news-archive#2009)
9. [Source](https://www.bbc.com/news/science-environment-22914076)
10. [Source](https://www.bbc.co.uk/news/science-environment-21934520)
11. [Source](https://sci.esa.int/web/herschel/-/51550-observation-gives-way-to-examination-as-herschel-coolant-runs-out)
12. BBC Things