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Stabilization of Electrodynamic Space Tethers

Award Information

National Aeronautics and Space Administration
Award ID:
Program Year/Program:
2001 / SBIR
Agency Tracking Number:
Solicitation Year:
Solicitation Topic Code:
Solicitation Number:
Small Business Information
Tethers Unlimited, Inc.
11711 N. Creek Pkwy S., Suite D113 Bothell, WA 98011-8804
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Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No
Phase 1
Fiscal Year: 2001
Title: Stabilization of Electrodynamic Space Tethers
Agency: NASA
Contract: N/A
Award Amount: $70,000.00


Electrodynamic tether propulsion can provide propellantless propulsion capability for a number of important missions in LEO, including stationkeeping for small satellites, boosting of the International Space Station, deorbit of malfunctioning satellites, and orbit raising of payloads. Theoretical analyses, however, indicate that electro-dynamic tethers will experience dynamical instabilities in which the electro-dynamic forces continually pump energy into the tether librations and oscillations. Unless these dynamics are controlled, these instabilities will lead to reduced thrust efficiency and, at worst, loss of control of the tether system. The proposed SBIR effort will develop methods for reliably monitoring the dynamics of both conducting and nonconducting tether structures, and develop control algorithms for stabilizing the dynamical behavior of electro-dynamic tethers. The effort will evaluate several different methods for accomplishing the dynamics monitoring and control, and select for further development the method that provides the optimum balance between reliable control and low hardware and computational costs. The SBIR effort will result in a tether dynamics control package, composed of both dynamics-sensing hardware and feedback control software algorithms, that will enable electro-dynamic tether systems such as propellantless orbital transfer, ISS tether reboost, momentum-exchange/electro-dynamic-reboost tether facilities, and microsatellite stationkeeping to operate safely and effectively.

Principal Investigator:

Robert Hoyt

Business Contact:

Robert L. Forward
Vice President
Small Business Information at Submission:

Tethers Unlimited, Inc.
8114 Pebble Ct. Clinton, WA 98236

Number of Employees:
Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No