The Collisional Evolution of Orbital Debris in Geopotential Wells and Disposal Orbits

Abstract

The Collisional Evolution of Orbital Debris in Geopotential Wells and Disposal Orbits Benjamin PolzineThis thesis investigates the orbital debris evolution in the geosynchronous disposal orbit regime and within geosynchronous orbits effected by the geopotential wells. A propagator is developed for the accurate simulation of GEO specific orbits and the required perturbations are determined and described. Collisions are then simulated in the selected regimes using a low velocity breakup model derived from the NASA EVOLVE breakup model. The simulations described in this thesis consider a set of perturbations including the geopotential, solar and lunar gravity, and solar radiation pressure forces. This thesis is based on a prior paper and additionally seeks to address an issue in simulating East-West trapped objects. The results show that this propagator successfully simulates the presence of all wells and the East-West entrapment, and the required perturbations are outlined. Five collision test cases were simulated, one for each type of entrapment and an additional for the disposal orbit.iv ACKNOWLEDGMENTS

Space Junk: The Risk of Space Missions and the Proposal of Solar Sail Technology to Mitigate the Problem

“…The space junk in low earth orbit (LEO), for example, tend to have a greater speed of translation and shorter periods than in other orbits, due to being closer to Earth suffering greater influence of the gravitational field and therefore requiring a larger tangential velocity of revolution corresponding to the centripetal acceleration. Consequently, according to [2], it is recorded that debris in this type of orbit can reach a speed 7 times greater than of a projectile of pistol, reaching up to 27,000 km/h. In future missions, space conditions, accidental and catastrophic problems may arise if objects of these speed orders collide with ships, satellites or stations.…”

“…According to [2][3][4][5], another alarming problem with space debris is related to the duration of "life" in Earth orbit. In GEO (geostationary orbit), which is of utmost importance due to the amount of existing active satellites located in its surroundings, the altitude favorable and synchronization with Earth's rotation, space debris can remain in orbit for hundreds of years at risk of collision and overfilling of the orbit due to the almost non-existent evasion of this debris.…”

“…In GEO (geostationary orbit), which is of utmost importance due to the amount of existing active satellites located in its surroundings, the altitude favorable and synchronization with Earth's rotation, space debris can remain in orbit for hundreds of years at risk of collision and overfilling of the orbit due to the almost non-existent evasion of this debris. The same goes for debris in LEO for perigee altitudes above 500 km where there is no effect of atmospheric drag, as [2][3][4], which in turn are also more susceptible to the unpredictability of the trajectory, causing more collision risks, due to the greater range of geopotential effects (EGT) due to the low altitudes. LEO's congestion makes it stand out against a worrying scenario, given that it is located right after the planet leaves for space and gives access to the other orbits.…”

“…This behavior in LEO is a major risk to the space environment, as it is an already congested region and collisions can significantly increase the debris population, as already occurred in 2009 when the Russian satellite Cosmos-2251, launched in 1993 and at the time deactivated, collided with the American communications satellite Iridium 33. As comment in [2], the accident occurred at an altitude of 790 km, over northeast Siberia, creating a gigantic cloud of debris, estimated after impact to be a cloud of more than 1600 new debris, bringing dangers to satellites in LEO and disabling the coordinates of the orbit where the accident occurred, where few have an estimate of re-entry into the atmosphere in the next 30 years after the collision.…”

Lixo Espacial: O Risco Atual Em Órbita Baixa Terrestre (Leo) E Uma Proposta De Mitigação

“…Os problemas dos riscos de colisões entre detritos e satélites já é algo que se destaca desde 2009, quando o satélite russo Cosmos-2251, lançado em 1993 e na época desativado, colidiu com o satélite de comunicações americano Iridium 33. O acidente ocorreu a 790 km de altitude, sobre o nordeste da Sibéria, criando uma gigantesca nuvem de escombros, sendo catalogados após impacto uma nuvem de mais de 1600 novos detritos com estimativa de entrada na atmosfera nos próximos 30 anos após colisão, e até lá trazendo perigos para satélites em LEO, inutilizando as coordenadas da órbita onde ocorreu o acidente (Polzine, 2017).…”