// PROPULSION SYSTEMS AND ENGINE TECHNOLOGY TERM
Tether Propulsion
Tether propulsion uses a long cable, or tether, to change a spacecraft's orbit without using traditional rocket fuel. It works by either pushing against a planetary magnetic field to create thrust or by exchanging momentum with another object, like a spinning yo-yo.
TECHNICAL DEFINITION
Tether propulsion is a form of propellantless spacecraft propulsion that utilizes long, conductive cables to generate thrust via the Lorentz force by interacting with a planetary magnetic field (electrodynamic tether) or to transfer orbital energy via momentum exchange or gravity gradient forces. This technology enables maneuvers like orbit raising, deorbiting, and station-keeping without consuming on-board propellant.
BACKGROUND
Field propulsion refers to spacecraft propulsion concepts in which thrust arises from interactions with external fields or ambient media, rather than primarily from onboard chemical propellant. Early ideas grew from studies of radiation pressure and electrically driven motion; later contractor and agency surveys organized advanced concepts under thermal, field, and photon headings. Several related propulsion systems discussed alongside field propulsion in the broader historical literature surveyed here have since been demonstrated in practice, including electrodynamic tethers in orbit, and applications such as EHD thrust devices. In narrower modern literature, related propellant-less propulsion discussions often focus on environment-coupled systems, while the historical contractor and survey literature treated field propulsion more broadly and sometimes grouped related terrestrial electromagnetic propulsion and some beamed-energy concepts within the same analytical framework.
READ MORE ON WIKIPEDIASYNONYMS & ALIASES
- electrodynamic tether
- momentum exchange tether
- space tether propulsion
- Lorentz force propulsion
- propellantless propulsion
- gravity gradient tether
USAGE NOTE
This technology is primarily experimental and often discussed for de-orbiting space debris or providing long-term, low-thrust propulsion for satellites.
DEVELOPERS
Organizations developing technology related to Tether Propulsion.
A company dedicated to the development of space tether transportation systems. They are known for designing the Momentum-Exchange/Electrodynamic-Reboost (MXER) tether system for boosting spacecraft to higher orbits without propellant.
The U.S. space agency has conducted extensive research and flight experiments on tether propulsion for decades, primarily through centers like the Marshall Space Flight Center (MSFC). The NASA Innovative Advanced Concepts (NIAC) program often funds studies on advanced tether applications.
JAXA has actively developed and tested electrodynamic tether technology. A notable example is the Kounotori Integrated Tether Experiments (KITE) on the HTV-6 cargo vehicle, aimed at demonstrating electrodynamic tether propulsion for space debris removal.
As a federally funded research and development center (FFRDC), The Aerospace Corporation conducts analysis, simulation, and concept development for advanced space systems, including various forms of tether propulsion and their applications for national security and civil space missions.
A company affiliated with the University of Illinois at Urbana-Champaign, CU Aerospace develops compact propulsion systems and satellite deorbit devices. They have worked on electrodynamic tethers for deorbiting CubeSats and other small satellites.
The NRL has a history of developing and flying tether experiments to study dynamics and survivability in space. Their research includes missions like the Tether Physics and Survivability (TiPS) experiment, which provided long-term data on tether dynamics.
Acquired by Voyager Space, Altius developed robotics for on-orbit services. They have engineered and proposed concepts using tethers for momentum exchange, satellite servicing, and payload capture, such as their STEM-based extendable grappling arms that can be used in tether-like operations.