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 Title: Solar radiation pressure, drag and gravitational effects on a dust particle in Earth orbit Author(s): Jagannatha, Bindu Advisor(s): Coverstone, Victoria L. Department / Program: Aerospace Engineering Discipline: Aerospace Engineering Degree Granting Institution: University of Illinois at Urbana-Champaign Degree: M.S. Genre: Thesis Subject(s): Solar Radiation Pressure Gravitational perturbations Dust particle orbit Montecarlo simulations Abstract: This work aims to further the research done on evaluating the effects of various perturbing forces on Earth-orbiting particles by numerical integration. One of the predominant perturbations on particle orbits is the solar radiation pressure (SRP), which is defined as the pressure exerted by the photons constituting the light from the Sun. Colombo et. al studied the orbital dynamics of smart-dust'' under the effects of SRP and atmospheric drag. The numerical model developed here will expand on that work, but will use Hamiltonian equations of motion instead of Gauss’ equations. This approach easily incorporates forces such as drag, SRP and J2 perturbations. Solar radiation pressure is switched off while the particle passes through the Earth's shadow. The model is developed in an Earth-Centric Inertial frame, where the Sun and the Moon are averaged to lie in the ecliptic plane with an obliquity of 23.6 degrees. None of the effects of perturbation are averaged, thus this study can provide the entire set of initial orbital elements of particles in Earth-orbit required to ensure a long lifespan. The differential equations of motion are numerically integrated using MATLAB's pre-packaged ode45. These formulations and assumptions are tested against results found in existing literature. The application of this model so far described is to select a set of initial orbital elements that will balance the dissipative effects of drag with coupling of SRP, J2 and Moon's gravity, thereby ensuring longer orbital lifetimes. The methodology employs Montecarlo simulations over the possible regime of some known initial conditions, while varying the others. A goldilocks'' region is chosen by superimposing the results from different Montecarlo runs that produce the least departure from the initial set of orbital elements at the end of one simulated orbit. These orbits are conjectured to have the longest lifespans; in a sample calculation, the orbital lifetime was increased by ~30 times by selecting a set of initial elements from this goldilocks'' region, as compared to an arbitrary set of initial conditions outside it. The eventual goal of this work is to aid precise orbital propagation of swarms of nano-satellites through the use of heavier computational resources. Due to the non-specific nature of all parameters used, this model can also be utilized for missions at other planetary bodies or those in lunar orbit. Inclusion of higher-order integrators or variational integrators (over the Runge-Kutta methods used here) may improve accuracy. Issue Date: 2012-12 URI: http://hdl.handle.net/2142/42385 Rights Information: Copyright 2012 Bindu Jagannatha Date Available in IDEALS: 2013-02-03 Date Deposited: 2012-12
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