James Cameron Bennett

Space Environment Research Centre

The tumbling motion of defunct satellite TOPEX/Poseidon (T/P) is governed by the μ-scale Solar Radiation Pressure (SRP) torque that spun up the satellite from the initial, nadir-pointing to the current fast spinning state [1]. In this paper, we advance the methods of Quanta Photogrammetry (QPM) in an effort to determine satellite attitude parameter...

The conventional detection of micrometeoroid and orbital debris (MMOD) impacts on satellites is based on in-situ sensing or direct, visual inspection of the retrieved surface elements exposed to the particle flux and thus requires active in-orbit operations. We propose Quanta Photogrammetry (QPM) as an optical method for remote detection of surface...

The global electro-optical (EO) and laser tracking sensor network was considered to investigate improvements to orbit prediction (OP) accuracy of space debris by combining angle and laser ranging data. However, it is worth noting that weather, schedule and visibility constraints can frequently limit the operations of such sensors, which may not res...

The hypertemporal light curves of the sunlit Ajisai satellite allow for reflectivity measurement of the individual on-board mirror panels. The photon counting technology developed at Graz Satellite Laser Ranging (SLR) station makes it possible to distinguish between the solar flux diffused and specularly reflected off the spinning Ajisai. The flux...

Two fundamentally different approaches to determine normality of state uncertainty are compared by application to a range of test cases. The first method is the Henze-Zirkler test, which operates on a random particle sample. The variability of its result is quantified. Using this method, breakdown of state normality has been found to occur in three...

The post-Newtonian approximation for general relativity is widely adopted by the geodesy and astronomy communities. It has been successfully exploited for the inclusion of relativistic effects in practically all geodetic applications and techniques such as satellite/lunar laser ranging and very long baseline interferometry. Presently, the levels of...

The breakup of Hitomi (ASTRO-H) on 26 March 2016 is analysed. Debris from the fragmentation is used to estimate the time of the event by propagating backwards and estimating the close approach with the parent object. Based on this method, the breakup event is predicted to have occurred at approximately 01:42 UTC on 26 March 2016. The Gaussian varia...

The TOPEX/Poseidon (T/P) altimetry mission operated for 13 years before the satellite was decommissioned in January 2006, becoming a large space debris object at an altitude of 1,340 km. Since the end of the mission, the interaction of T/P with the space environment has driven the satellite’s spin dynamics. Satellite Laser Ranging (SLR) measurement...

Orbital propagation is a key element in many fields of space research. Over the decades, scientists have developed numerous orbit propagation algorithms, often tailored to specific use cases that vary in available input data, desired output as well as demands of execution speed and accuracy. Conjunction assessments, for example, require highly accu...

In 2010 an international consortium led by RMIT University was awarded a multi-million-dollar Australian Space Research Program (ASRP) Project—“Platform Technologies for Space Atmosphere and Climate”. This project is part of the Australian Government’s recent space-related initiative to support national strategic, economic and social objectives. Th...

The high repetition rate Satellite Laser Ranging system Graz delivers the millimeter precision range measurements to the corner cube reflector panels of Ajisai. The analysis of 4599 passes measured from October 2003 until November 2014 reveals the secular precession and nutation of Ajisai spin axis due to the gravitational forces as predicted by Ku...

The requirement to regularly track an increasing number of objects will result in straining existing tracking networks. This paper investigates the orbit prediction capability of an orbit determination process using very short-arc optical and laser debris tracking data for objects in low-Earth orbits. An analysis is carried out to determine the red...

This paper introduces the multi-million-dollar Australian Space Research Program (ASRP) Project—“Platform Technologies for Space Atmosphere and Climate,” recently awarded to an international consortium led by RMIT University, and reports the current progress and some results achieved so far. The project is part of the Australian Government’s recent...

In the last 2 years EOS Space Systems has conducted three debris tracking campaigns using its Space Debris Tracking System (SDTS) at Mt Stromlo. The first one was an optical (passive) tracking campaign undertaken in May 2012. The second one was a laser tracking campaign in July/August 2012, and the third one was also a laser tracking campaign in Ap...

Earlier studies have shown that an orbit prediction accuracy of 20 arc seconds ground station pointing error for 1-2 day predictions was achievable for low Earth orbit (LEO) debris using two passes of debris laser ranging (DLR) data from a single station, separated by about 24 hours. The accuracy was determined by comparing the predicted orbits wit...

Services delivered from satellites in the near-Earth space environment are under threat from orbiting space debris from over 50 years of space operations. Computational modelling studies have shown that even under optimistic mitigation scenarios remediation is necessary to curb the growth. In fact, certain regions of the low- Earth orbit are alread...

Orbit manoeuvre of low Earth orbiting (LEO) debris using ground-based lasers has been proposed as a cost-effective means to avoid debris collisions. This requires the orbit of the debris object to be determined and predicted accurately so that the laser beam can be locked on the debris without the loss of valuable laser operation time. This paper p...

Background: The eradicability of rain-splashed crop diseases was examined by modelling the spread of lupin anthracnose over a spatially heterogeneous landscape. Two hypotheses were investigated: (i) in most cases, rain-splashed diseases are unlikely to be eradicable because spread will be too extensive by the time the disease is detected; (ii) the...

This paper presents a new method for estimating ballistic coefficients (BCs) of low perigee debris objects from their historical two line elements (TLEs). The method uses the drag perturbation equation of the semi-major axis of the orbit. For an object with perigee altitude below 700 km, the variation in the mean semi-major axis derived from the TL...

Film blowing is a highly complex industrial process used to manufacture thin sheets of polymer. Models that describe this process are highly nonlinear and numerical instabilities often occur when solving the highly nonlinear differential equations. This paper investigates the structure of typical solutions that arise when the polymer is assumed to...

Film blowing, by which thin polymer film is manufactured, is an industrial process with products used in a wide range of applications. Modelling of this process requires solving the highly nonlinear dif-ferential equations necessary to describe the complex chemical and physical interactions involved. Earlier work applied a mixture of an-alytic and...

The film blowing process, by which thin polymer films are manu-factured, is modelled by highly nonlinear differential equations. Typi-cally, analysis of these using numerical techniques leads to instabilities. Our earlier work used an iteration process to construct the film bub-ble profile and some associated quantities for the simplest case of a N...

Film blowing is an industrial process used to produce thin sheets of polymer with a wide range of applications; for example, plastic bags. We apply analytic and numerical techniques to model this process in the simplest case where the blown material is a Newtonian fluid op-erating under non-isothermal conditions. In particular, we obtain the therma...

The techniques and methodology of singular perturbation theory analyse the film blowing of an incompressible Newtonian film. An appropriate, physically relevant small parameter guides the method of matched asymptotic expansions to obtain straightforward closed form approximate expression for the film profile throughout the blown region. This then d...