Self balanced electrodynamic tethers for space debris mitigatation
- Paper number
IAC-06-B6.4.03
- Author
Dr. Jesus Pelaez, Technical University of Madrid (UPM), Spain
- Coauthor
Mr. M. Sanjurjo, Technical University of Madrid (UPM), Spain
- Year
2006
- Abstract
The space debris is a danger for the space operations on Earth. The basic hazard in space caused by debris is damage or even destruction by collision. Current risk levels are small, but are steadily increasing, and will become unacceptable in the future. Since most of the debris are inactive objects, its active removal is becoming a necessity. The 98% of the debris is concentrated in ≈ 1500 objects with masses above 100 kg. De-orbiting of some of these objects would markedly decrease the total mass of the debris population. Electrodynamic tethers can be used with clear advantages for remove active or inactive orbital debris from space. These devices are able to exert electrodynamic drag at heights where the aerodynamic drag is negligible (e.g., 2000 km). This production of drag is reliable, cheaper than other solutions and can be used to deorbit satellites at the end of their lifetime (and also other types of space debris). An electrodynamic tether does not use fuel to deorbit an object; quite the opposite, it can recover a significant part of the orbital energy of the object to be deorbited, if this option is considered advisable. These significant advantages of electrodynamic tethers means that they are soon likely to play a decisive role in deorbiting. Recently a new concept has been introduced in this field: the self-balanced electrodynamic tether (SBET) (see [1-3]). This concept takes advantage of the properties of the tether current profile in the case of bare tethers. In a SBET the Lorentz torque about the system center of mass becomes zero (or negligible) even for a large tether current. The balance condition is obtained by adjusting the system mass distribution, and it results (to a first approximation) in a Lorentz torque that is almost independent of the tether current. This is the key point of the concept: the successful combination of high tether currents with small values of the Lorentz torque. In this paper we present some results showing the performances of different SBETs designed for deorbiting objects from LEO. We focus on the bare tether concept since it provides higher tether current than other configurations. We explain the control scheme that leads to the smooth dynamics exhibited during the deorbiting of the space debris.
[1] J. Peláez, Self balanced electrodynamic tethers, Paper AIAA 2004-5309, The 2004 AAS/AIAA Astrodynamics Specialist Conference, Providence, RI, USA, 2004.
[2] J. Peláez, M. Sanjurjo & J. Fontdecaba, Satellite deorbiting using a self balanced electrodynamic tether, Paper IAC-04-A.5.08, The 55th IAC, Vancouver, Canada, 2004.
[3] J. Peláez & M. Sanjurjo, Generator regime of self balanced electrodynamic bare tethers, Advances in the Astronautical Sciences, Vol.120 (PART II), pp. 1651-1670, 2005.
- Abstract document
- Manuscript document
IAC-06-B6.4.03.pdf (🔒 authorized access only).
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