The Elastic Tether Dynamics suite of tools describes the dynamic behaviour of tethers under various forcing scenarios. Developed as part of a GSP project within the ESA Clean Space Initiative, the suite covers the full life cycle of an active debris removal mission, including pre-tension, single or multiple re-entry burn, post burn orbit dynamics, target vehicle motion and tether behaviour during re-entry. It is designed to permit the selection of tether properties, such that undesirable dynamic behaviours, including chaser / target collision can be designed out of the active debris removal mission.

  • Tether Models - Tethers are modelled as mass / spring / damper bead systems with one or more sections with uniform properties. The dynamic properties of these systems under forcing are solved analytically giving very high performance and permitting the use of very high fidelity representations.
  • Orbital Dynamics - Free body motion post burn is modelled using the Hill-Clohessy-Wiltshire equation with multiple re-tensioning and damping events.
  • Target Rotational Dynamics - The behaviour of the target is independently modelled as a simple pendulum with numerous forcing models including continuous, pulsed, pulsed sinusoidal and user defined functions.
  • Configurable - All aspects of ETD can be configured using JavaScript. This enables the tuning of fidelity versus execution time to be performed.
  • Portable - Written in a combination of Java and JavaScript, ETD is fully supported on Windows, Unix / Linux and OS X.