One of the foremost space science and engineering issues facing society today is conquering Earth's space debris problem, being paramount to managing the increasing orbital traffic in near-Earth space and safeguarding satellite operations. This pressing problem is fundamentally connected with the modern fields of space domain awareness and space traffic management, which integrate many traditional areas of space research into a single focused topic. A major challenge is predicting with sufficient accuracy the location and collision risks of all significant resident space objects, a problem that has been compounded in recent years with the launch of numerous small satellites by many nations and the proliferation of orbital debris. Space traffic, mostly driven by geopolitical and economic factors, has always been subject to considerable fluctuations, but many indications point to a significant increase of traffic in low-Earth orbit (LEO), the most densely populated orbital lanes. OneWeb, SpaceX, and Amazon, in particular, have each launched ambitious plans to place thousands of satellites in LEO to provide low-latency broadband internet to the world. The deployment of these mega-constellations represents hitherto unknown challenges to the Earth's most congested and contested orbital environment.
Earth satellite orbits can possess an extraordinarily rich spectrum of dynamical behaviors, from stable resonant configurations to significant chaotic drifts in circumterrestrial phase space throughout their orbital lifetimes. This talk will review these intriguing phenomena and highlight their deeper connections with current aspects of space sustainability. One particularly compelling ideology is based on the judicious use of the resulting instabilities to prescribe natural Earth re-entry itineraries to remedy the space debris problem or to navigate the phase space. In this seminar, I will review recent theoretical and numerical investigations on the orbital dynamics of resident space objects, and show how resonances can profoundly affect the behavior of these bodies, in both dissipative and Hamiltonian settings. This work ties together observation, theory, and simulation, and fosters connections between fields apparently quite different in character and emphasis. In fact, the interdisciplinary nature of Hamiltonian dynamics is deeply ingrained in its history, and this work belongs to that rich tradition. I will specifically note its cross-cutting nature and relevance to space domain awareness, planetary science, applied dynamical systems theory, planned and proposed spacecraft missions, and satellite constellation design and control.
