Low work-function tether Deorbit Kit Articles uri icon

authors

  • TARABINI CASTELLANI, LORENZO
  • TAJMAR, MARTIN
  • WATZIG, KATJA
  • POST, A.
  • PLAZA, J.F.
  • ORTEGA, A.
  • GIMENEZ, A.
  • URGOITI BOLUMBURU, EDUARDO
  • SANCHEZ ARRIAGA, GONZALO
  • BORDERES MOTTA, GABRIEL
  • LORENZINI, ENRICO C.

publication date

  • September 2020

start page

  • 332

end page

  • 339

issue

  • 3

volume

  • 7

International Standard Serial Number (ISSN)

  • 2468-8967

abstract

  • This works presents a system level analysis of a Deorbit Kit (DK) based on electrodynamic tether technology. The analysis is focused on two relevant scenarios for deorbiting space debris: (i) Earth Observation (EO) satellites with mass in the range of 700 kg -1000 kg and initial orbital altitude of 800 km and 98° inclination, and (ii) Mega Constellation (MC) spacecraft in the order of 200 kg and initial orbit at 1200 km of altitude and 90° of inclination. The scenarios have been selected considering the orbits that are already suffering from the space debris problem or will suffer in the next future. The DK implements a bare electrodynamic tether for capturing electrons passively from the ambient plasma while three different methods are considered for emitting the electrons back to the plasma to reach a steady electrical current on the tether. The three studied options to close the electrical circuit are: (a) a hollow cathode, which has a high technological maturity but needs expellant and a little of power, (b) a thermionic emitter, which does not involve expellant but needs power, and (c) a Low Work-function Tether (LWT) that does not need neither expellant nor power because it has a segment coated with a special material that emits electrons passively through the thermionic and photoelectric effects. In order to provide a fully autonomous operation even in case of critical failure of the mother spacecraft, the DK includes a deployment mechanism, a telemetry and telecommand system, a complete Attitude Determination and Control System with attitude sensors (GNSS, sun sensors, magnetometer) and actuators (magneto torquers), solar panels and batteries. Upon activation, the DK autonomously de-tumbles the satellite, deploys a tether and carries out the satellite's de-orbiting. The study presents DK architectures, mass budgets and simulation results for the two scenarios...

keywords

  • deorbit kit (dk); electrodynamic tether technology