Long cables or tethers operated in various modes (gradient stabilized, vibrating, rotating, or pumped) have often been proposed for space propulsion. The tether is a mechanism that transfers energy and momentum to or from a space vehicle from the tether, planetoid, or some other space vehicle. A number of experiments will be conducted to demonstrate this advanced space propulsion technique using single-strand tethers. Damage estimates to the tether by space debris, however, indicate that the average lifetime of a long single-strand tether is only about one month. The goal of this project is to design and analytically and experimentally analyze a failsafe, multistrand tether structure for space propulsion that will maintain its overall structured integrity and mission capability under multiple severings by space debris, while still being capable of deployment and retrieval using relatively simple reeling apparatus. The availability of a long-life, reliable tether structure will allow NASA to seriously consider this advanced space propulsion system, which, when properly designed, can repeatedly move payloads between LEO and GEO, into deep space, and to the surface of the moon and Mars, without requiring refueling. Compared to chemical rockets, tethers are inexpensive, lightweight, reusable, and easy for small businesses to develop, test, and deploy. They are of simple construction and use no hazardous or exotic materials. Early commercial applications will be for the transfer of payloads between LEO to GEO. Later applications will include transfer of payloads from LEO to the surfaces of the Moon and Mars.tethers, cables, space debris, space propulsionSTATUS: Phase I Only
