# Chandra X-ray Observatory

> NASA space observatory

**Wikidata**: [Q49002](https://www.wikidata.org/wiki/Q49002)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Chandra_X-ray_Observatory)  
**Source**: https://4ort.xyz/entity/chandra-x-ray-observatory

## Summary
The Chandra X-ray Observatory is a NASA space telescope named after astrophysicist Subrahmanyan Chandrasekhar that observes distant celestial objects from orbit, specifically detecting X-ray emissions from astronomical phenomena.

## Key Facts
- Launched on July 23, 1999, aboard Space Shuttle Columbia (STS-93) from Kennedy Space Center Launch Complex 39B
- Operated by the Smithsonian Astrophysical Observatory and managed by the Marshall Space Flight Center
- Part of NASA's Great Observatories program
- Follows the Compton Gamma Ray Observatory and is followed by the Spitzer Space Telescope
- Mass: 5864.9 kg (launch weight), 4789.9 kg (dry weight), 976.6 kg (propellant)
- Dimensions: length 13.8 meters, width 4.3 meters (overall), 19.5 meters (with solar arrays extended)
- Focal length: 10 meters
- Carries scientific instruments including High Resolution Camera, Advanced CCD Imaging Spectrometer, and transmission gratings
- In a highly elliptical orbit around Earth with an orbital period of approximately 3808.7 minutes

## FAQs
### Q: When was the Chandra X-ray Observatory launched?
A: It was launched on July 23, 1999, aboard the Space Shuttle Columbia.

### Q: Who operates the Chandra X-ray Observatory?
A: It is operated by the Smithsonian Astrophysical Observatory and managed by the Marshall Space Flight Center.

### Q: What is the Chandra X-ray Observatory used for?
A: It observes distant celestial objects by detecting X-ray emissions from astronomical phenomena.

### Q: What is the orbit of the Chandra X-ray Observatory?
A: It follows a highly elliptical orbit around Earth with an orbital period of about 3808.7 minutes.

## Why It Matters
The Chandra X-ray Observatory has revolutionized our understanding of the universe by providing unprecedented high-resolution X-ray images of cosmic phenomena. Its ability to detect X-rays from distant objects has allowed astronomers to study black holes, neutron stars, galaxy clusters, and other extreme environments. The observatory has made thousands of important discoveries, including detailed observations of supernova remnants, active galactic nuclei, and the behavior of matter under extreme conditions. By providing insights into the most energetic processes in the universe, Chandra has contributed significantly to our understanding of cosmology and astrophysics.

## Notable For
- One of NASA's Great Observatories program, alongside Hubble Space Telescope and others
- Achieved the highest angular resolution of any X-ray telescope in orbit
- Operates in a highly elliptical orbit that allows it to reach temperatures near absolute zero for optimal detector performance
- Named after Nobel laureate Subrahmanyan Chandrasekhar, who predicted the existence of white dwarf stars
- Carries advanced scientific instruments including the High Resolution Camera and transmission gratings for spectroscopy

## Body
### Technical Specifications
The Chandra X-ray Observatory has several key technical specifications:
- **Mass**: 5864.9 kg at launch (including propellant), 4789.9 kg dry weight, 976.6 kg propellant
- **Dimensions**: Length 13.8 meters, width 4.3 meters (overall), 19.5 meters with solar arrays extended
- **Focal length**: 10 meters
- **Power**: Provided by a spacecraft solar array (2 units) and nickel-hydrogen batteries (3 units)
- **Scientific instruments**: High Resolution Camera, Advanced CCD Imaging Spectrometer, High Energy and Low Energy Transmission Gratings

### Orbit and Operations
The observatory follows a highly elliptical orbit around Earth with:
- **Periapsis**: 1487.8 km from Earth
- **Apoapsis**: 147331.6 km from Earth
- **Orbital period**: Approximately 3808.7 minutes (about 63 hours)
- **Inclination**: 38.6737 degrees
- **Eccentricity**: 0.9026344

### Launch and Deployment
Chandra was launched on July 23, 1999, from Kennedy Space Center Launch Complex 39B aboard Space Shuttle Columbia (STS-93). The Inertial Upper Stage (IUS-27) placed it into its operational orbit. The spacecraft was deployed at an altitude of approximately 10,000 km and then maneuvered to its final orbit.

### Scientific Impact
Since its launch, Chandra has made numerous groundbreaking discoveries:
- Detailed observations of supernova remnants and their interaction with surrounding interstellar medium
- Studies of black holes and neutron stars in binary systems
- Analysis of galaxy clusters and their hot intergalactic medium
- Investigations of active galactic nuclei and supermassive black holes
- Observations of cosmic X-ray background and dark matter

The observatory continues to operate as of March 21, 2023, providing valuable data to astronomers worldwide.

```json
{
  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "Chandra X-ray Observatory",
  "description": "NASA space telescope named after Subrahmanyan Chandrasekhar that observes X-ray emissions from distant celestial objects",
  "url": "https://chandra.harvard.edu/",
  "sameAs": ["https://www.wikidata.org/wiki/Q48183", "https://en.wikipedia.org/wiki/Chandra_X-ray_Observatory"],
  "additionalType": "space telescope"
}

## References

1. [Source](https://chandra.harvard.edu/about/axaf_mission.html)
2. [Source](http://chandra.harvard.edu/contest/co_winners.html)
3. Virtual International Authority File
4. Jonathan's Space Report
5. [Source](https://chandra.harvard.edu/graphics/press/fact7-print.pdf)
6. [Source](http://chandra.harvard.edu/about/specs.html)
7. Freebase Data Dumps. 2013
8. [Source](https://heavens-above.com/orbit.aspx?satid=25867)
9. [Source](https://space.skyrocket.de/doc_stage/ius.htm)
10. [Source](https://chandra.harvard.edu/about/specs.html)
11. [Source](https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/naif_ids.html)