IADC Action Item 19.1: Potential Benefits and Risks of using Electrodynamic Tethers for End-of-life De-orbit of LEO Spacecraft

Pardini C., Hanada T., Krisko H. P.

Space Debris  Mitigation Strategies  Spacecraft de-orbiting  Electrodynamic Tethers 

Over nine thousand satellites and other trackable objects are currently in orbit around the Earth, along with many smaller particles. As the low Earth orbit is not a limitless resource, some sort of debris mitigation measures are needed to solve the problem of unusable satellites and spent upper stages. De-orbiting devices based on the use of conducting tethers have been recently proposed as innovative solutions to mitigate the growth of orbital debris. However, tethers in space introduce unusual problems when viewed from the space debris perspective. They present a much greater risk to operating spacecraft due to their considerably large collision cross-sectional area. Because of their small diameter, tethers of normal design may have a high probability of being severed by impacts with relatively small meteoroids and orbital debris, while the resulting tether fragments may pose additional risks to operating spacecraft. Such space debris related concerns prompted the Inter-Agency Space Debris Coordination Committee (IADC) to recognize this demanding task and to open, at the 19th IADC meeting held in Cologne, Germany, from 22 to 23 March 2001, a new Action Item (AI 19.1) with the purpose of investigating the potential benefits and risks of using tethers in space. The task was assigned to Working Group 2 (Environment and Data Base) and a WG 2 member, Gerhard Drolshagen of the European Space Agency, volunteered to collect information on the existing and under development tools to analyse the dynamics of tethers in space and to estimate the collision risk of tethers with space debris and operative spacecraft. The preliminary status of the task was presented by G. Drolshagen at the 20th IADC meeting held in Guilford, Surrey, England, from 9 to 12 April 2002. Afterwards, another WG 2 member, Carmen Pardini for the Italian Space Agency, volunteered to coordinate this study and, at the 21st IADC meeting held in Bangalore, India, from 10 to 13 March 2003, C. Pardini informed the IADC WG 2 members on the advanced status of the Action Item giving three presentations: 1. Overview of space tether applications: state-of-the-art knowledge and tools; 2. De-orbiting spacecraft with electrodynamic tether devices; 3. Potential benefits and risks of using electrodynamic tethers for end-of-life de-orbit of LEO spacecraft. At the same meeting, following thought-provoking discussions, the specifics of the task were formulated and a proposal to address the Electrodynamic Tether (EDT) systems survivability concern was advanced inside WG 2. The original AI designation, i.e.

Source: Project report, IADC, 2006