# orbiter

> spacecraft which orbits a planet or other celestial body

**Wikidata**: [Q928667](https://www.wikidata.org/wiki/Q928667)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Orbiter)  
**Source**: https://4ort.xyz/entity/orbiter

## Summary  
An **orbiter** is a spacecraft designed to enter and remain in orbit around a planet, moon, or other celestial body. It is a subclass of an artificial satellite— a human‑made object placed into orbit for scientific, communication, or exploration purposes.

## Key Facts  
- **Definition:** A spacecraft that orbits a planet or other celestial body (Wikidata description).  
- **Classification:** Subclass of *artificial satellite* (Wikidata `subclass_of`).  
- **Aliases:** Includes orbiteur, Mondorbiter, المسبار المداري, مسابير مدارية, الدائر, عربة مدارية, etc.  
- **Wikipedia entry:** Title *Orbiter* with 23 language sitelinks (be, bg, ca, de, en, eo, fa, fr, he, hu).  
- **Commons category:** *Orbiters (spacecraft)* (Wikidata `commons_category`).  
- **Identifiers:** Freebase ID `/m/04j9w3k`; Google Knowledge Graph ID `/g/121srfbh`; Unified Astronomy Thesaurus ID 1183.  
- **Related classes:** *Lunar orbiter* (orbits the Moon) and *orbital module* (spacecraft section used only in space).  

## FAQs  
### Q: What exactly is an orbiter?  
**A:** An orbiter is a type of spacecraft that is placed into and remains in orbit around a planetary body or other celestial object, allowing it to conduct long‑term observations, communications, or scientific experiments.  

### Q: How does an orbiter differ from a regular satellite?  
**A:** All orbiters are artificial satellites, but the term “orbiter” is typically used for missions whose primary purpose is to stay in orbit around a specific target (e.g., a planet or moon) for exploration, whereas “satellite” can also refer to any object—commercial, navigation, or communication—placed in orbit.  

### Q: Can you give examples of famous orbiters?  
**A:** Yes. Notable examples include the *Mars Reconnaissance Orbiter*, *Venus Express*, *Pioneer Venus Orbiter*, *Mars Global Surveyor*, and the *Jupiter Europa Orbiter* concept.  

## Why It Matters  
Orbiters are essential tools for planetary science and space exploration. By staying in a stable orbit, they can continuously monitor atmospheric conditions, surface geology, magnetic fields, and radiation environments over months or years—data that would be impossible to gather from brief fly‑by missions. This sustained presence enables high‑resolution mapping, climate monitoring, and the relay of communications for landers and rovers on the surface. Orbiters also serve practical roles, such as providing navigation aids, supporting interplanetary internet concepts (e.g., the cancelled *Mars Telecommunications Orbiter*), and testing technologies for future deep‑space missions. Their contributions have reshaped our understanding of the Solar System, informed mission planning, and fostered international collaboration across agencies like NASA, ESA, and ISRO.

## Notable For  
- Being the primary vehicle class for long‑duration planetary observation missions.  
- Enabling the first detailed global maps of Mars (*Mars Global Surveyor*) and Venus (*Venus Express*).  
- Acting as communication relays for surface assets, exemplified by the *Mars Reconnaissance Orbiter*.  
- Serving as testbeds for advanced technologies, such as interplanetary internet concepts.  
- Forming the basis for numerous mission concepts targeting outer planets (e.g., *Neptune Odyssey*, *Uranus Orbiter and Probe*).

## Body  

### Definition and Scope  
- An **orbiter** is a spacecraft whose mission profile requires it to enter and maintain an orbit around a celestial body.  
- It is a human‑made object, thus falling under the broader class of **artificial satellites**.  

### Classification  
- **Subclass of:** Artificial satellite (Wikidata).  
- **Related subclasses:**  
  - *Lunar orbiter* – orbits the Moon.  
  - *Orbital module* – a spacecraft section used only while in space, not for re‑entry.  

### Naming and Identifiers  
- **Aliases:** orbiteur, Mondorbiter, المسبار المداري, مسابير مدارية, الدائر, عربة مدارية, العربات المدارية, etc.  
- **Freebase ID:** `/m/04j9w3k`.  
- **Google Knowledge Graph ID:** `/g/121srfbh`.  
- **Unified Astronomy Thesaurus ID:** 1183.  
- **Art & Architecture Thesaurus ID:** 300233907.  
- **Wikipedia title:** *Orbiter* (23 language sitelinks).  

### Representative Missions (Examples)  
| Mission | Target Body | Agency | Status |
|---------|-------------|--------|--------|
| **Mars Reconnaissance Orbiter** | Mars | NASA | Operating |
| **Venus Express** | Venus | ESA | Completed (2006‑2014) |
| **Pioneer Venus Orbiter** | Venus | NASA | Completed (1978‑1992) |
| **Mars Global Surveyor** | Mars | NASA/JPL | Completed (1996‑2006) |
| **Jupiter Europa Orbiter** | Europa (Jupiter) | NASA (concept) | Cancelled |
| **Neptune Odyssey** | Neptune | NASA (concept) | Proposed |
| **Uranus Orbiter and Probe** | Uranus | ESA/JAXA (concept) | Proposed |

These missions illustrate the breadth of scientific goals—atmospheric studies, surface mapping, magnetic field measurements, and technology demonstrations—achieved by orbiters.

### Technical Characteristics (Typical)  
- **Propulsion:** Chemical or electric thrusters for orbit insertion and maintenance.  
- **Power:** Solar arrays (inner‑planet missions) or radioisotope thermoelectric generators (outer‑planet missions).  
- **Communication:** High‑gain antennas for data relay to Earth and, when applicable, to surface assets.  
- **Payloads:** Cameras, spectrometers, magnetometers, radar, and particle detectors tailored to mission objectives.  

### Role in Mission Architecture  
- **Science Platform:** Provides long‑term, repeated observations of a target body.  
- **Relay Node:** Serves as a communications hub for landers/rovers (e.g., *Mars Reconnaissance Orbiter* for the *Curiosity* rover).  
- **Technology Demonstrator:** Tests new instruments, navigation techniques, and autonomous operations for future deep‑space missions.  

### Future Outlook  
Concept studies such as *Neptune Odyssey*, *Uranus Orbiter and Probe*, and *Jupiter Ganymede Orbiter* indicate continued reliance on orbiters for exploring the outer Solar System. Emerging ideas like interplanetary internet rely on a network of orbiters to provide continuous data links between Earth and distant planetary assets.

## Schema Markup
```json
{
  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "Orbiter",
  "description": "Spacecraft which orbits a planet or other celestial body.",
  "url": "https://en.wikipedia.org/wiki/Orbiter",
  "sameAs": [
    "https://en.wikipedia.org/wiki/Orbiter"
  ],
  "additionalType": "ArtificialSatellite"
}

## References

1. Freebase Data Dumps. 2013