ELKE (Extended long-term simulation and cost analysis of active debris removal for space debris)

Project Description

Active removal of space debris is a currently much discussed topic. To stabilize the current situation, especially in the low Earth orbit (LEO) regime, it might be necessary to remove certain objects with high mass and high collision risk from their orbit. As such missions are very expensive, it is necessary to assess their impact beforehand to both achieve an economic and scientific basis for political decisions.

In prior projects, the impact of active debris removal on the object population in Earth bound orbits was already investigated. For this, long-term projections of the space debris environment were performed, assuming different scenarios for the evolution of space flight. Among these a business-as-usual scenario (BAU) with different post-mission-disposal rates (PMD) and several active debris removal (ADR) scenarios. Furthermore, using cost models, the damage and avoidance costs of different scenarios were estimated.

The capabilities of the used tools for long-term projections, and with this the quality of the results, are continuously improved. In the direct predecessor “ELA – Extended long-term analysis of the future space debris population under consideration of active removal measures”, the structure of the used tool for long-term analysis LUCA (Long Term Utility for Collision Analysis) was extended, to allow GPU parallelization of object propagation to shorten the computational time for the simulation. Furthermore, extended scenarios of the long-term evolution were simulated.

Figure 1: General layout of LUCA2, [Müller, S., Radtke, J., Metz, M., Stoll, E., Langzeitsimulationen von Weltraummüll mit LUCA 2, Deutscher Luft- und Raumfahrtkongress (DLRK), Braunschweig, Germany, 2016, oral presentation 420143.]

In ELKE, two different aims are to be achieved: First of all, the used long-term simulation software will completely be redesigned and re-implemented. Main reasons for this are an increased flexibility in the simulations that can be performed, but also are the introduction of a highly modular structure to allow an easy exchange of models. Alongside with these functional changes, up-to-date software engineering standards will be applied during the implementation.

 

 

Figure 2: Collision rates in one Monte-Carlo run of a propagated space debris population using Orbit-Trace (OT) and CUBE for the collision rate determination [Radtke, J., Müller, S., Schaus, V., Stoll, E., LUCA2 - An Enhanced Long-Term Utility for Collision Analysis, 7th European Conference on Space Debris (ECSD), Darmstadt, Germany, 2017.].

Additionally the cost modelling will be improved. Based on a student’s thesis, it will be possible to analyse the impact of using different propulsion systems to deorbit satellites as well as different mission profiles. Using a to be defined interface, the model will be implemented directly into the long-term simulation tool, to analyse the scenarios directly based on their economic efficiency. Furthermore, the impact of uncertainties in the simulation parameters and simulation models themselves will be assessed. On the basis of these investigations, further long-term simulations will be performed.

In a recent extension to the study, it was decided to furthermore investigate the impact of so called Mega-Constellations on the long-term evolution of the space debris environment. The focus for this part of the project will be the appropriateness of current statistical collision rate determination algorithms for very large constellations of satellites, consisting of more than 500 objects.

Project Term:

September 2015 –December 2017

Funding:

The project is funded by the German Federal Ministry for Economic Affairs and Energy under contract 50LZ1501.

Publications:

• Proceeding

Radtke, J., Müller, S., Schaus, V., Stoll, E., LUCA2 - An Enhanced Long-Term Utility for Collision Analysis, 7th European Conference on Space Debris (ECSD), Darmstadt, Germany, 2017.

Müller, S., Radtke, J., Metz, M., Stoll, E., Langzeitsimulationen von Weltraummüll mit LUCA 2, Deutscher Luft- und Raumfahrtkongress (DLRK), Braunschweig, Germany, 2016, oral presentation 420143.