{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/140692"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/140692","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Investigation Into Geometry and Behavior of Cislunar GEO-Grazer Orbits","abstract":"This thesis investigates a class of cislunar trajectories referred to as GEO-grazers: orbits that traverse the Earth–Moon system while grazing or passing below geosynchronous Earth orbit (GEO). These trajectories are of interest for cislunar space domain awareness (SDA) because they provide natural dynamical pathways by which spacecraft or debris originating far beyond GEO can approach critical orbital infrastructure. The analysis is conducted primarily within the planar circular restricted three-body problem (PCR3BP), using the Jacobi constant to characterize different geometries and timescales of GEO-grazers. Case studies of real cislunar objects are first examined to demonstrate that GEO-grazing behavior has already occurred, both as a result of deliberate mission design and chaotic dynamics. A generalized modeling approach is then used to generate GEO-grazers by time-reversing trajectories that originate at GEO and reach the exterior realm of cislunar space. Across ranges of Jacobi constants, GEO-grazers are shown to exhibit structured behavior, including clustering of lunar realm entry and exit locations, non-monotonic trends in time of flight to GEO, and consistent grouping of GEO impact or grazing regions relative to the position of the Moon. Finally, the practical implementation of GEO-grazers is explored through the identification of cislunar parking orbits via the simulation of impulsive maneuvers that transfer these orbits onto GEO-grazing trajectories. The results demonstrate that maneuvers on the order of tens of meters per second can be sufficient to induce GEO-grazing behavior, particularly when executed within the lunar realm. Collectively, these findings indicate that the existence of GEO-grazers has important implications for the detection, classification, and intent assessment of objects operating in the Earth–Moon environment.","abstract_html":"This thesis investigates a class of cislunar trajectories referred to as GEO-grazers: orbits that traverse the Earth–Moon system while grazing or passing below geosynchronous Earth orbit (GEO). These trajectories are of interest for cislunar space domain awareness (SDA) because they provide natural dynamical pathways by which spacecraft or debris originating far beyond GEO can approach critical orbital infrastructure. The analysis is conducted primarily within the planar circular restricted three-body problem (PCR3BP), using the Jacobi constant to characterize different geometries and timescales of GEO-grazers. Case studies of real cislunar objects are first examined to demonstrate that GEO-grazing behavior has already occurred, both as a result of deliberate mission design and chaotic dynamics. A generalized modeling approach is then used to generate GEO-grazers by time-reversing trajectories that originate at GEO and reach the exterior realm of cislunar space. Across ranges of Jacobi constants, GEO-grazers are shown to exhibit structured behavior, including clustering of lunar realm entry and exit locations, non-monotonic trends in time of flight to GEO, and consistent grouping of GEO impact or grazing regions relative to the position of the Moon. Finally, the practical implementation of GEO-grazers is explored through the identification of cislunar parking orbits via the simulation of impulsive maneuvers that transfer these orbits onto GEO-grazing trajectories. The results demonstrate that maneuvers on the order of tens of meters per second can be sufficient to induce GEO-grazing behavior, particularly when executed within the lunar realm. Collectively, these findings indicate that the existence of GEO-grazers has important implications for the detection, classification, and intent assessment of objects operating in the Earth–Moon environment.","abstract_has_math":false,"creators":["Soccio-Mallon, Spencer Patrick"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Aerospace Engineering","degree_department":"Aerospace and Ocean Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Ross, Shane David"],"committee_members":["Fitzgerald, Riley McCrea","Schroeder, Kevin Kent"],"year":2026,"date_issued":"2026-01-08","date_published":"2026-01-08","updated_at":"2026-07-22T22:18:42Z","subjects":["GEO-Grazer","Cislunar Dynamics","Orbital Geometry","Earth–Moon System"],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:45488"],"render_values":[{"text":"vt_gsexam:45488","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10919/140692","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Ross, Shane David"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Fitzgerald, Riley McCrea","Schroeder, Kevin Kent"]},{"key":"dc:contributor.department","label":"Department","values":["Aerospace and Ocean Engineering"]},{"key":"dc:creator","label":"Author","values":["Soccio-Mallon, Spencer Patrick"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2026-01-09T09:01:15Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2026-01-09T09:01:15Z"]},{"key":"dc:date.issued","label":"Date","values":["2026-01-08"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["GEO-Grazer","Cislunar Dynamics","Orbital Geometry","Earth–Moon System"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:45488"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10919/140692"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This thesis investigates a class of cislunar trajectories referred to as GEO-grazers: orbits that traverse the Earth–Moon system while grazing or passing below geosynchronous Earth orbit (GEO). These trajectories are of interest for cislunar space domain awareness (SDA) because they provide natural dynamical pathways by which spacecraft or debris originating far beyond GEO can approach critical orbital infrastructure. The analysis is conducted primarily within the planar circular restricted three-body problem (PCR3BP), using the Jacobi constant to characterize different geometries and timescales of GEO-grazers. Case studies of real cislunar objects are first examined to demonstrate that GEO-grazing behavior has already occurred, both as a result of deliberate mission design and chaotic dynamics. A generalized modeling approach is then used to generate GEO-grazers by time-reversing trajectories that originate at GEO and reach the exterior realm of cislunar space. Across ranges of Jacobi constants, GEO-grazers are shown to exhibit structured behavior, including clustering of lunar realm entry and exit locations, non-monotonic trends in time of flight to GEO, and consistent grouping of GEO impact or grazing regions relative to the position of the Moon. Finally, the practical implementation of GEO-grazers is explored through the identification of cislunar parking orbits via the simulation of impulsive maneuvers that transfer these orbits onto GEO-grazing trajectories. The results demonstrate that maneuvers on the order of tens of meters per second can be sufficient to induce GEO-grazing behavior, particularly when executed within the lunar realm. Collectively, these findings indicate that the existence of GEO-grazers has important implications for the detection, classification, and intent assessment of objects operating in the Earth–Moon environment."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["This study is an investigation into a category of cislunar orbits called GEO-grazers that are potentially relevant to cislunar space domain awareness. GEO-grazers are cislunar orbits that reach or pass through geosynchronous orbit (GEO), potentially threatening space infrastructure in a novel way. The study begins with case study analyses of objects that have exhibited GEO-grazing behavior, demonstrating that such trajectories already exist in cislunar space. A modeling framework is then used to examine how GEO-grazers can be deliberately engineered by propagating trajectories backwards in time from GEO to cislunar space. Across a range of orbital energies, types of GEO-grazers are identified and their geometry and timescales are characterized. Finally, GEO-grazer parking orbits are simulated with maneuvers to show how an object can transition from a benign cislunar orbit onto a GEO-grazing trajectory."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Investigation Into Geometry and Behavior of Cislunar GEO-Grazer Orbits"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Ross, Shane David"],"dc:contributor.committeemember":["Fitzgerald, Riley McCrea","Schroeder, Kevin Kent"],"dc:contributor.department":["Aerospace and Ocean Engineering"],"dc:creator":["Soccio-Mallon, Spencer Patrick"],"dc:date.accessioned":["2026-01-09T09:01:15Z"],"dc:date.available":["2026-01-09T09:01:15Z"],"dc:date.issued":["2026-01-08"],"dc:description.abstract":["This thesis investigates a class of cislunar trajectories referred to as GEO-grazers: orbits that traverse the Earth–Moon system while grazing or passing below geosynchronous Earth orbit (GEO). These trajectories are of interest for cislunar space domain awareness (SDA) because they provide natural dynamical pathways by which spacecraft or debris originating far beyond GEO can approach critical orbital infrastructure. The analysis is conducted primarily within the planar circular restricted three-body problem (PCR3BP), using the Jacobi constant to characterize different geometries and timescales of GEO-grazers. Case studies of real cislunar objects are first examined to demonstrate that GEO-grazing behavior has already occurred, both as a result of deliberate mission design and chaotic dynamics. A generalized modeling approach is then used to generate GEO-grazers by time-reversing trajectories that originate at GEO and reach the exterior realm of cislunar space. Across ranges of Jacobi constants, GEO-grazers are shown to exhibit structured behavior, including clustering of lunar realm entry and exit locations, non-monotonic trends in time of flight to GEO, and consistent grouping of GEO impact or grazing regions relative to the position of the Moon. Finally, the practical implementation of GEO-grazers is explored through the identification of cislunar parking orbits via the simulation of impulsive maneuvers that transfer these orbits onto GEO-grazing trajectories. The results demonstrate that maneuvers on the order of tens of meters per second can be sufficient to induce GEO-grazing behavior, particularly when executed within the lunar realm. Collectively, these findings indicate that the existence of GEO-grazers has important implications for the detection, classification, and intent assessment of objects operating in the Earth–Moon environment."],"dc:description.abstractgeneral":["This study is an investigation into a category of cislunar orbits called GEO-grazers that are potentially relevant to cislunar space domain awareness. GEO-grazers are cislunar orbits that reach or pass through geosynchronous orbit (GEO), potentially threatening space infrastructure in a novel way. The study begins with case study analyses of objects that have exhibited GEO-grazing behavior, demonstrating that such trajectories already exist in cislunar space. A modeling framework is then used to examine how GEO-grazers can be deliberately engineered by propagating trajectories backwards in time from GEO to cislunar space. Across a range of orbital energies, types of GEO-grazers are identified and their geometry and timescales are characterized. Finally, GEO-grazer parking orbits are simulated with maneuvers to show how an object can transition from a benign cislunar orbit onto a GEO-grazing trajectory."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:45488"],"dc:identifier.uri":["https://hdl.handle.net/10919/140692"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["GEO-Grazer","Cislunar Dynamics","Orbital Geometry","Earth–Moon System"],"dc:title":["Investigation Into Geometry and Behavior of Cislunar GEO-Grazer Orbits"],"dc:type":["Thesis"],"thesis:degree_discipline":["Aerospace Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:18:42Z"}