James Bennett, EOS Space Systems; Michael Lachut, EOS Space Systems; David Kooymans, EOS Space Systems; Alex Pollard, EOS Space Systems; Craig Smith, EOS Space Systems, Sven K. Flegel, Space Environment Research Centre; Marek Moeckel, Space Environment Research Centre; Joseph O’Leary, Space Environment Research Centre; Richard Samuel, Space Environment Research Centre; Jeffrey Wardman, Space Environment Research Centre; Daniel Kucharski, Space Environment Research Centre; James Allworth, Australian Centre for Field Robotics, University of Sydney; Andrew Edwards, Optus Satellite Systems; Anthony Belo, Optus Satellite Systems
Keywords: Conjunction Assessemnts, Orbital Debris, Space Situational Awareness, Laser Manoeuvre
Abstract:
This paper presents results from a new operational conjunction and threat warning service developed in Australia. As part of the Space Environment Research Centre (SERC) a collaboration under the Australian Governments Cooperative Research Centre scheme a conjunction and threat warning service has been developed to support satellite operators and enable a laser debris manoeuvre experiment.
The founding members of SERC are EOS Space Systems (Australia), RMIT University (Australia), ANU University (Australia), Lockheed Martin (US), Optus (Australia), and NICT (Japan). The overall goal of SERC is to demonstrate the remote manoeuvre of on-orbit objects using a ground-based laser. Small perturbations or nudges will be made to an objects orbit so that a collision is avoided. The method is useful for reducing the risk of potential collision events for objects that have no ability to manoeuvre. If successful, the mitigation method will serve to reduce the growth in debris in low-Earth orbit by avoiding collisions, until other active debris removal methods can remove mass from the near-Earth orbit environment.
Before manoeuvring an object in space, accurate knowledge of the debris environment is needed to select the right conjunction pair. Then the ability to predict the future paths of the satellite and debris objects accurately is also needed to assess whether the manoeuvre will decrease the risk of a collision. This is a fundamental component that has been developed within the Space Asset Management (SAM) program at SERC. The service is equally applicable to the laser manoeuvre demonstration experiment and regular conjunction assessment services for satellite operators.
The SAM program has worked closely with Optus Satellite Systems to develop the service. Optus operate a fleet of 5 geostationary satellites. Their experience in conjunction avoidance manoeuvres has provided valuable guidance in the development of the conjunction assessment service. Case studies and results from the conjunction and threat warning service are presented.
The operational system is backed by a centralised database-backed storage system that maintains traceability. This allows follow-up analyses into space events, where each space situational awareness product can be provided, along with the information that was used to generate it. Efficient sensor scheduling methods are employed for tasking a network of sensors using information gain. The conjunction assessment case studies provided in this paper are followed up by tasking EOS Space Systems network of tracking sensors in Australia.
Observation track correlation methods have been developed that reliably associate each tracklet with an object. The automation of the data pipeline and the orbit determination process provide updated state vector information which is then used in follow-up conjunction assessments. The conjunction analyses along with nonlinear and non-Gaussian state error propagation provide a conjunction data message with actionable information. Object characterisation techniques have also been developed based on the light signatures of objects of interest which assists with the demonstration that an on-orbit perturbation has been successful.
This paper also presents the objects selected as candidates for the laser manoeuvre campaign, including the object characteristics that have been determined during the tracking campaigns.
The paper finishes with the next steps for the Conjunction and Threat Warning service, including the future capabilities that will be integrated in to the service.
Date of Conference: September 17-20, 2019
Track: Astrodynamics