# tethered satellite

> artificial satellite consisting of two parts connected by a cable

**Wikidata**: [Q3473930](https://www.wikidata.org/wiki/Q3473930)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Tether_satellite)  
**Source**: https://4ort.xyz/entity/tethered-satellite

## Summary  
A tethered satellite is an artificial satellite made up of two separate components that are linked together by a long cable, or tether. This configuration is used to study the physics of long‑length tethers in space and to test concepts such as momentum exchange, power generation, and orbital maneuvering.

## Key Facts  
- **Definition**: An artificial satellite consisting of two parts connected by a cable (tether).【wikidata_description】  
- **Classification**: Subclass of *artificial satellite* and instance of the spacecraft type.【instance_of】【subclass_of】  
- **Core component**: The tether itself is listed as a “has part” of the system.【has_part(s)】  
- **Aliases**: Also known as “tethered satellites” or “tethered spacecraft”.【aliases】  
- **Research programs**: The United States operated the *Tethers in Space Physics Satellite* (TiPS 1a and TiPS 1b) and the *Tethered Satellite System* (TSS‑1 on STS‑50 and TSS‑1R on STS‑75).【TiPS 1a】【TiPS 1b】【TSS‑1】【TSS‑1R】  
- **Japanese nanosatellites**: Multiple Japanese tethered nano‑satellites have been launched, including *Space Tethered Autonomous Robotic Satellite* (STARS) series—STARS‑I, STARS‑II, STARS‑Cube, STARS‑Miniature Elevator, and STARS‑Elevator CubeSat—re‑entering between 2014 and 2022.【Space Tethered Autonomous Robotic Satellite I】【Space Tethered Autonomous Robotic Satellite II】【Space Tethered Autonomous Robotic Satellite - Cube】【Space Tethered Autonomous Robotic Satellite - Miniature Elevator】【Space Tethered Autonomous Robotic Satellite - Elevator CubeSat】  
- **Identifiers**: Fast ID 1148310; Library of Congress authority ID sh86004283; Yale LUX concept ID 71ab1de4‑f30c‑4e61‑8cc3‑ef3195af7c3d; Google Knowledge Graph ID /g/1213hfnx.【fast_id】【library_of_congress_authority_id】【‎yale_lux_id】【google_knowledge_graph_id】  
- **Wikipedia**: Article titled “Tether satellite” with multilingual pages (English, Esperanto, French, Italian).【wikipedia_title】【wikipedia_languages】  

## FAQs  
### Q: What is the purpose of connecting two satellite parts with a tether?  
A: The tether allows scientists to study the dynamics of long cables in orbit, test concepts for propulsion, power generation, and momentum exchange, and evaluate how tethers affect orbital behavior.  

### Q: Which missions have demonstrated tethered satellite technology?  
A: Notable missions include the U.S. TiPS 1a/1b experiments, the Tethered Satellite System (TSS‑1 on STS‑50 and TSS‑1R on STS‑75), and Japan’s STARS series of nano‑satellites launched between 2014 and 2022.  

### Q: Are tethered satellites still being developed today?  
A: Yes. Recent Japanese STARS nano‑satellites (e.g., STARS‑Elevator CubeSat, re‑entered in 2022) show ongoing interest, and the concept continues to be explored for future propulsion and power‑generation applications.  

### Q: How does a tethered satellite differ from a conventional satellite?  
A: Conventional satellites are single, rigid bodies, whereas a tethered satellite comprises two separate masses linked by a cable, enabling unique physical interactions such as electrodynamic thrust and tether‑induced orbital changes.  

### Q: Can a tethered satellite generate electricity?  
A: In theory, a conductive tether moving through Earth’s magnetic field can induce an electric current (electrodynamic tether), a principle tested in several tethered‑satellite experiments.  

## Why It Matters  
Tethered satellites provide a low‑mass, low‑fuel means to manipulate spacecraft trajectories and generate power directly from orbital motion. By exploiting the interaction between a long conductive tether and Earth’s magnetic field, engineers can produce electrodynamic thrust without expending propellant, potentially extending mission lifetimes and reducing launch costs. The technology also offers a platform for fundamental physics research, such as measuring plasma density, studying tether dynamics, and validating models of orbital mechanics under non‑standard forces. Successful tether experiments have paved the way for concepts like space elevators, momentum‑exchange tethers for cargo transport, and tether‑based de‑orbiting solutions, all of which could reshape how we access and operate in space.  

## Notable For  
- **First large‑scale tether experiment**: The U.S. *Tethered Satellite System* (TSS‑1) flown on STS‑50 in 1992 was the inaugural attempt to deploy a multi‑kilometre tether from the Space Shuttle.  
- **Electrodynamic thrust demonstration**: TSS‑1R on STS‑75 (1996) successfully generated measurable current and thrust, confirming the electrodynamic tether concept.  
- **Miniaturized tether research**: Japan’s STARS nano‑satellite series demonstrated that tether experiments can be performed with CubeSat‑class platforms, dramatically lowering cost and entry barriers.  
- **Long‑duration tether deployment**: TiPS 1a/1b (1996) achieved a 20‑km tether deployment, one of the longest successful tether lengths in orbit at the time.  
- **Cross‑national collaboration**: The tethered‑satellite field includes contributions from the United States, Japan, and European researchers, highlighting its global scientific relevance.  

## Body  

### Definition and Classification  
- A tethered satellite is defined as an artificial satellite composed of two separate masses linked by a tether.  
- It is a subclass of *artificial satellite* and an instance of the broader *spacecraft* type.  
- The tether itself is formally recognized as a “has part” of the system.  

### Historical Milestones  

#### United States Programs  
- **TiPS 1a / TiPS 1b (1996)** – Part of the *Tethers in Space Physics Satellite* program; each satellite represented one half of a tether experiment, deploying a 20‑km conductive cable.  
- **Tethered Satellite System (TSS‑1)** – Flown on Space Shuttle *Columbia* during STS‑50 (1992); first attempt to release a 20‑km tether from orbit.  
- **Tethered Satellite System‑R (TSS‑1R)** – Flown on Space Shuttle *Columbia* during STS‑75 (1996); achieved a 19.7‑km tether deployment and measured electrodynamic currents.  

#### Japanese Nano‑Satellite Experiments  
- **Space Tethered Autonomous Robotic Satellite I (STARS‑I)** – Launched 2014, re‑entered 2014.  
- **Space Tethered Autonomous Robotic Satellite II (STARS‑II)** – Launched 2014, re‑entered 2014.  
- **Space Tethered Autonomous Robotic Satellite – Cube** – Launched 2018, re‑entered 2018.  
- **Space Tethered Autonomous Robotic Satellite – Miniature Elevator** – Launched 2021, re‑entered 2021.  
- **Space Tethered Autonomous Robotic Satellite – Elevator CubeSat** – Launched 2022, re‑entered 2022.  

These missions illustrate a trend toward using CubeSat platforms for tether research, reducing cost while still achieving scientific objectives.  

### Technical Principles  

- **Electrodynamic Tether**: A conductive tether moving through Earth’s magnetic field induces an electric current, which can produce thrust or drag depending on the circuit configuration.  
- **Momentum Exchange**: By reeling a tether in or out, a satellite can transfer momentum to a payload, altering its orbit without propellant.  
- **Power Generation**: The induced current can be harvested to generate electrical power for onboard systems.  

### Applications and Future Directions  

- **Space Debris Mitigation**: Tethers can be used to lower the perigee of defunct satellites, accelerating atmospheric re‑entry.  
- **Propulsion‑less Maneuvering**: Future missions may employ long tethers for station‑keeping or inter‑orbital transfers without conventional thrusters.  
- **Space Elevator Concepts**: Tether research underpins long‑term visions of tether‑based elevators extending from Earth’s surface to geostationary orbit.  

## Schema Markup  
```json
{
  "@context": "https://schema.org",
  "@type": "Thing",
  "name": "tethered satellite",
  "description": "An artificial satellite consisting of two parts connected by a cable (tether).",
  "url": "https://en.wikipedia.org/wiki/Tether_satellite",
  "sameAs": [
    "https://www.wikidata.org/wiki/Q1148310"
  ],
  "additionalType": "Spacecraft"
}

## References

1. Faceted Application of Subject Terminology
2. National Library of Israel Names and Subjects Authority File