Benefits and risks of using electrodynamic tethers to de-orbit spacecraft

Paper number

IAC-06-B6.2.10

Author

Dr. Carmen Pardini, ISTI-CNR, Italy

Coauthor

Prof. Toshiya Hanada, Kyushu University, Japan

Coauthor

Dr. Paula H. Krisko, ESCG/Jacobs Sverdrup, United States

Year

2006

Abstract

Space tethers represent an exciting and innovative technique offering immense technological and scientific opportunities. Propellantless propulsion and momentum-exchange transportation have been considered among the most promising applications of tethers in space since early studies in the field over 35 years ago. Despite a small number of full-scale experiments made so far using space tethers, the possibility of de-orbiting spacecraft by means of electrodynamic tethers has been on the drawing board of theorists for almost a decade. By using electrodynamic drag to greatly increase the orbital decay rate, an electrodynamic space tether can remove spent or dysfunctional spacecraft from low Earth orbit rapidly and safely. Moreover, the low mass requirements of such tether devices make them highly advantageous compared to conventional rocket-based de-orbit systems. However, tethers are usually very long and thin, providing increased opportunities for something to go wrong. In particular, a tether system is much more vulnerable to space debris impacts than a typical spacecraft and its design must prove to be safe to a certain confidence level before being adopted for potential applications. 

To assess the space debris related concerns, a new task (Action Item 19.1) on the “Benefits and Risks of using Electrodynamic Tethers to De-orbit Spacecraft” was defined by the Inter-Agency Space Debris Coordination Committee (IADC), in March 2001. The task was assigned to the IADC Working Group 2, on “Environment and Data Base”, and a study plan was successively formulated  with the main objective of investigating the potential risk to the tether system integrity due to impacts with space debris. Two tests were proposed to compute the fatal impact rate of meteoroids and orbital debris on space tethers in circular orbit, at different altitudes and inclinations, as a function of the tether diameter, and to assess the survival probability of an electrodynamic tether system during typical de-orbiting missions. IADC members of three agencies (ASI, JAXA and NASA) volunteered to participate in the study and different computational approaches were specifically developed in the framework of this IADC task. 

This paper summarizes the content of the IADC AI 19.1 final report. In particular, it introduces the potential benefits and risks of using tethers in space, it describes the assumptions made in the study plan, it compares and discusses the results obtained by ASI, JAXA and NASA for the two tests proposed. Some general conclusions and recommendations are eventually highlighted as a result of a massive and intensive study.         

Abstract document

IAC-06-B6.2.10.pdf

Manuscript document

IAC-06-B6.2.10.pdf (🔒 authorized access only).

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