# US Orbital Segment

> international components of the International Space Station

**Wikidata**: [Q2025902](https://www.wikidata.org/wiki/Q2025902)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/US_Orbital_Segment)  
**Source**: https://4ort.xyz/entity/us-orbital-segment

## Summary
The US Orbital Segment (USOS) is the collection of international components of the International Space Station (ISS). It is primarily operated by the National Aeronautics and Space Administration (NASA) and includes major hardware contributions from the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), and the Canadian Space Agency (CSA).

## Key Facts
- **Definition:** Classified as a space station segment comprising the international components of the International Space Station.
- **Parent Structure:** The segment is a part of the International Space Station.
- **Primary Operator:** National Aeronautics and Space Administration (NASA).
- **International Operators:**
    - Japan Aerospace Exploration Agency (JAXA) operates the **Kibo** module.
    - European Space Agency (ESA) operates the **Columbus** laboratory and **Cupola**.
    - Canadian Space Agency (CSA) operates the **Mobile Servicing System**.
- **Key Component:** Includes the Bigelow Expandable Activity Module (BEAM), an experimental expandable space station module.
- **Also Known As:** USOS, U.S. National Laboratory, ISS National Laboratory, ISSNL.
- **Visual Record:** Image available via Wikimedia Commons (File: US_Orbital_Segment_-_May_2011.jpg).

## FAQs
### Q: Who owns and operates the US Orbital Segment?
A: While the segment is primarily operated by NASA, it is a collaborative effort. The European Space Agency, Japan Aerospace Exploration Agency, and Canadian Space Agency operate specific modules and systems within the segment, such as Columbus, Kibo, and the Mobile Servicing System.

### Q: What is the US Orbital Segment?
A: The US Orbital Segment is the designation for the collection of components on the International Space Station that are contributed by the United States and its international partners in Europe, Japan, and Canada.

### Q: What specific modules are part of this segment?
A: The segment includes the Kibo module (Japan), the Columbus module and Cupola (Europe), and the Mobile Servicing System (Canada). It also includes experimental modules such as the Bigelow Expandable Activity Module.

## Why It Matters
The US Orbital Segment serves as a critical infrastructure hub for microgravity research and space exploration. Functioning as a "National Laboratory in space," it provides a unique platform for scientific discovery that is distinct from the Russian Segment of the ISS. The segment represents a monumental achievement in international engineering, integrating distinct technologies from NASA, ESA, JAXA, and CSA into a single, cohesive orbital outpost. By facilitating experiments in biology, physics, astronomy, and materials science, the USOS plays a pivotal role in advancing human knowledge and preparing for future deep-space missions. Its designation as the U.S. National Laboratory underscores its importance in leveraging space for both scientific and commercial advancement.

## Notable For
- **International Collaboration:** Unifying hardware and operations from the US, Europe, Japan, and Canada under one orbital segment.
- **National Laboratory Status:** Being officially designated as the U.S. National Laboratory (ISSNL).
- **Expandable Technology:** Hosting the Bigelow Expandable Activity Module (BEAM), a pioneer in expandable habitat technology.
- **Major Scientific Hubs:** Housing critical research facilities like the Columbus laboratory and the Kibo module.
- **Robotic Capability:** Featuring the Mobile Servicing System, essential for station maintenance and capture operations.

## Body
### Structural Definition
The US Orbital Segment (USOS) is defined as a **space station segment** and serves as the grouping of international components attached to the International Space Station. It distinguishes itself from the Russian Orbital Segment both physically and operationally.

### Operational Control
The segment is a multinational operation led by the United States.
*   **NASA (National Aeronautics and Space Administration):** Acts as the primary operator.
*   **ESA (European Space Agency):** Applies to the **Columbus** laboratory and the **Cupola**.
*   **JAXA (Japan Aerospace Exploration Agency):** Applies to the **Kibo** module.
*   **CSA (Canadian Space Agency):** Applies to the **Mobile Servicing System**.

### Key Hardware Components
The USOS is composed of various pressurized modules and external structures:
*   **Kibo:** The Japanese Experiment Module.
*   **Columbus:** The primary research laboratory for the European Space Agency.
*   **Cupola:** An ESA-built observatory module with seven windows.
*   **Mobile Servicing System:** The robotic system provided by Canada.
*   **Bigelow Expandable Activity Module (BEAM):** An experimental expandable module attached to the station to test expandable habitat technology.

### Nomenclature and Identification
The segment is identified in various databases and languages by multiple names and codes:
*   **Acronyms:** USOS, ISSNL.
*   **Titles:** U.S. National Laboratory, ISS National Laboratory.
*   **International Names:** アメリカ軌道セグメント, 米国軌道セグメント, 미국 궤도 세그먼트 (Korean).
*   **Identifiers:** It holds a Microsoft Academic ID of 130217813 and a Freebase ID of /m/09g6v0j.

## References

1. Freebase Data Dumps. 2013