James Bennett, EOS Space Systems and Space Environment Research Centre; Michael Lachut, EOS Space Systems and Space Environment Research Centre; Daniel Kucharski, Space Environment Research Centre and University of Texas at Austin; Sven K. Flegel, Space Environment Research Centre; Marek Moeckel, Space Environment Research Centre; James Allworth, EOS Space Systems; David Kooymans, EOS Space Systems; Alex Pollard, EOS Space Systems; Craig Smith, EOS Space Systems; Joseph O’Leary, Space Environment Research Centre and University of South Australia; Hansani Thanippuli Kankanamalage, Space Environment Research Centre and University of South Australia; Richard Samuel, Space Environment Research Centre and ANU University
Keywords: Optical and laser tracking, sensor network, database/catalogue, space debris, conjunction assessments
Abstract:
This paper reports the progress of the development of a new conjunction and threat warning service for satellite operators and a laser manoeuvre demonstration. The status and characteristics of the network of sensors being used is described and the progress of the space situational awareness service being developed is provided along with a timeline for full operational capability.
The construction of a new site in Learmonth Western Australia a joint venture between EOS Space Systems and Lockheed Martin, with support from the Australian Department of Defence sees new optical and laser ranging systems installed to supplement EOSs existing site at Mt Stromlo, Canberra. Four telescopes have been installed at Learmonth: two 1-metre laser beam directors and two 0.7 metre Geo Trackers. The installation of a 0.7 metre GEO Tracker by EOS Space Systems for the Space Environment Research Centre (SERC) at Mount Stromlo, supplements EOSs existing 1.8 metre Space Debris Tracking System.
The sensor network is automated and can be adapted from day-to-day tasking to perform custom mission requests and ad-hoc tasking, for example, facilitating tasking from external organisations for observation collection. An information gain based scheduler is also being developed. An example of a typical daily mission cycle is: perform an all-on-all conjunction assessments, schedule the sensors to collect observations on the objects of interest, correlate the tracks with known objects, generate new orbital elements by fitting the collected observations, and re-task the sensors based on a new conjunction assessment. During a session the telescope domes will open and perform the tasking automatically and shut down and close when the session has finished.
At SERC the goal is to contribute to the mitigation of the debris environment by using high powered continuous wave lasers to apply photon pressure to perturb objects on orbit so that they avoid a collision. To demonstrate this goal, several operational components are needed to ensure a debris object is not moved into a less favourable trajectory, for example, after perturbing the orbit there is a higher chance of collision. This requires knowledge of all objects and their behaviour in the vicinity of the demonstration. The space situational awareness system is the culmination of a number of research programs.
SERC are developing a catalogue utilising the tracking data collected by the sensor network described above. Within the catalogue are object states and covariances as well as object characteristics. Traceability of catalogue change events has been an important component of the development and has been designed to facilitate the research developments being developed in SERC as they come into fruition. The development of high-rate photometric light sampling methods allow for the objects spin characteristics to be estimated, as well as albedo, optical cross-section, and other object characteristics and behaviours. The passive and active tracking observations are all stored in a tracks database and correlated with objects, with the uncorrelated tracks stored for later assessment and correlation.
The orbit element generation process is performed using a Batch Least Squares process, numerically integrating the equations of motion. The main perturbing forces are present in the force model and at the moment the automated element generation assumes a spherical object. Future enhancements will see non-spherical objects considered in the automated element generation.
The conjunction assessments have been parallelised to run efficiently on a GPU with a propagator interface allowing the use of different propagators. The software has been developed so that it is multi-platform. Nonlinear and non-Gaussian error propagation has also been developed within SERC and provides more realistic collision probability assessments, and the prediction in the breakdown of Gaussianity.
Information on the catalogue status, size and accuracy is reported as well as the integration and deployment of the conjunction and threat warning services.
Date of Conference: September 11-14, 2018
Track: Astrodynamics