Advanced Maui Optical and Space Surveillance Technologies Conference

UNSW Canberra has a program of experiments onboard the M2 formation flying CubeSat mission to provide truth datafor available space situational awareness (SSA) sensors and modelling algorithms. The paper outlines the programof experiments and deployments planned throughout the early, main, and extended operation phases of the missionthat provide opportunities for SSA observations. The mission comprises 2x6U CubeSats. Each satellite uses a 3-axisattitude control system to exploit differential atmospheric drag forces between the spacecraft to control the along-trackformation. The differential aerodynamic formation control enables the satellites to remain within an acceptable alongtrack offset to perform the main mission experiments. Several important opportunities to collect benchmark SSAdata are present throughout the mission. The CubeSat pair are initially conjoined as a 12U satellite and, followinga scheduled command from the UNSW Canberra ground station, will be impulsively pushed apart in the along-trackdirection by a spring to create a formation of 2x6U satellites. The separation of the spacecraft, followed by solar paneland antennae deployment, mark significant changes to the configuration, radar cross section, and orbit, during thisearly operations phase. The solar panel deployment increases the maximum frontal area of the spacecraft from 0.043m2in stowed configuration to 0.293 m2 when fully deployed. The attitudes of the spacecraft will be controlled toarrest the along-track separation of the spacecraft via the action of differential aerodynamic drag. The satellites featureGPS and attitude determination and control for accurate time, position, velocity, and attitude information, which isroutinely available in the satellite telemetry.The change detection experiments planned for the mission use the US Air Force Academy (USAFA) 0.5 m raven classFalcon Telescope Network and UNSW Canberra’s 0.36 m Rowe-Ackermann Schmidt Astrograph (RASA). Photometry and astrometry from these sensors are used in combination with synthetic sensor data through application of novelmachine-learning frameworks to provide estimates for the satellites’ configuration status and attitude profile duringthe observations. The synthetic optical sensor data will be produced from an in-house high-fidelity GPU acceleratedray-tracing simulation tool that can model multiple reflections and account for complex material reflectance properties. Progress on the development of the GPU tool are presented. The latter stages of the mission investigate advanceddifferential aerodynamic control methodologies. The impact of sensor uncertainty and operational constraints on theaccuracy of differential aerodynamic formation control manoeuvres will be analysed and quantified during the mission. A modelling and simulation framework will employ coupled ionosphere/thermosphere models with high fidelityforce propagation tools to provide higher fidelity estimates of the non-conservative forces imparted on the spacecraftby the atmosphere than standard models provide. The extended mission phase contains an ambitious space environment research experiment that seeks to measure ‘ionospheric aerodynamics’ effects imparted on the spacecraft. Theexperiment has been developed from theoretical and numerical research at UNSW Canberra that studies the forcecreated when a charged body interacts with the weakly ionized plasma in the ionosphere in LEO. The interaction iscontrolled from charge plates located on the extremity of the extended solar panels. The configuration and concept ofoperations are presented