Bron Nelson, Computer Sciences Corporation/NASA Ames Research Center, Fan Yang Yang, MEI/NASA Ames Research Center, Roberto Carlino, STC/NASA Ames Research Center, Andres Dono Perez, MEI/NASA Ames Research Center, Nicolas Faber, SGT/NASA Ames Research Center, Chris Henze, NASA Ames Research Center ,Arif Goktug Karacalioglu, / NASA Ames Research Center, Conor O’Toole, University College Dublin/NASA Ames Research Center, Jason Swenson, LMCO/NASA Ames Research Center, Jan Stupl, SGT / NASA Ames Research Center
Keywords: space debris mitigation, conjunction analysis, laser, parallel computing
Abstract:
This paper provides a status update on the implementation of a flexible, long-term space debris simulation approach. The motivation is to build a tool that can assess the long-term impact of various options for debris-remediation, including the LightForce space debris collision avoidance scheme.
State-of-the-art simulation approaches that assess the long-term development of the debris environment use either completely statistical approaches, or they rely on large time steps in the order of several (5-15) days if they simulate the positions of single objects over time. They cannot be easily adapted to investigate the impact of specific collision avoidance schemes or de-orbit schemes, because the efficiency of a collision avoidance maneuver can depend on various input parameters, including ground station positions, space object parameters and orbital parameters of the conjunctions and take place in much smaller timeframes than 5-15 days. For example, LightForce only changes the orbit of a certain object (aiming to reduce the probability of collision), but it does not remove entire objects or groups of objects. In the same sense, it is also not straightforward to compare specific de-orbit methods in regard to potential collision risks during a de-orbit maneuver. To gain flexibility in assessing interactions with objects, we implement a simulation that includes every tracked space object in LEO, propagates all objects with high precision, and advances with variable-sized time-steps as small as one second. It allows the assessment of the (potential) impact of changes to any object. The final goal is to employ a Monte Carlo approach to assess the debris evolution during the simulation time-frame of 100 years and to compare a baseline scenario to debris remediation scenarios or other scenarios of interest. To populate the initial simulation, we use the entire space-track object catalog in LEO. We then use a high precision propagator to propagate all objects over the entire simulation duration. If collisions are detected, the appropriate number of debris objects are created and inserted into the simulation framework. Depending on the scenario, further objects, e.g. due to new launches, can be added. At the end of the simulation, the total number of objects above a cut-off size and the number of detected collisions provide benchmark parameters for the comparison between scenarios. The simulation approach is computationally intensive as it involves ten thousands of objects; hence we use a highly parallel approach employing up to a thousand cores on the NASA Pleiades supercomputer for a single run.
This paper describes our simulation approach, the status of its implementation, the approach in developing scenarios and examples of first test runs.
Date of Conference: September 15-18, 2015
Track: Poster