Astrodynamics Commons^™

Deep Space Mission Opportunities To Planet Nine & Eris, Allison G. Carroll

Masters Theses

This research focuses on interplanetary mission design concepts, with the first topic being the study of mission opportunities to Planet Nine, otherwise known as Planet X. Previous studies have speculated about the existence of a large, distant planet beyond the orbits of Neptune and Pluto. A recent study based on the apparent clustering of perihelia and orbital planes of distant Kuiper Belt Objects identified the most probable values for five of the planet’s orbital elements. However, the true anomaly is still unknown. In this research, a range of critical mission parameters for a Planet X trajectory is analyzed as a …

Development Of A Database For Rapid Approximation Of Spacecraft Radiation Dose During Jupiter Flyby, Sarah Gilbert Stewart

Masters Theses

Interplanetary and deep space missions greatly benefit from the utilization of gravitational assists to reach their final destinations. By closely “swinging by” a planet, a spacecraft can gain or lose velocity or change directions without requiring any expenditure of propulsion. In today’s budget-driven design environment, gravity assist flybys reduce the need for on-board fuel and propulsion systems, thereby reducing overall cost, increasing payload and mission capacity, increasing mission life, and decreasing travel time. It is expected that many future missions will also be designed to swing by Jupiter in order to utilize a gravity assist. However, there is a risk …

Improved Modeling Of Atmospheric Entry For Meteors With Nose Radii Between 5cm And 10m, Jakob Dale Brisby

Masters Theses

Atmospheric entry studies typically look closely at the peak heating rate that a body encounters during its trajectory. This is an extremely important phenomenon to study because it allows engineers to determine if a trajectory is possible with given materials and craft design specifications. It also allows designers to choose what type of method will be used for mitigating the enormous heat fluxes during entry. In general, it is accepted that during the super-sonic flight regime the body will continue to be heated and an ablative heat shield often is used to deal with these heating processes. The theory outlined …

Trajectory Optimization For A Misson To The Trojan Asteroids, Shivaji Senapati Gadsing

Masters Theses

The problem of finding a minimum-fuel trajectory for a mission to the Jovian Trojan asteroids is considered. The problem is formulated as a modified traveling salesman problem. Two different types of algorithms such as an exhaustive search algorithm and a serial rendezvous search algorithm are developed. The General Mission Analysis Tool (GMAT) is employed for finding optimum trajectories with minimal fuel consumption. The selection of a minimum-fuel mission trajectory, and the associated target asteroids, will be a key factor in determining feasibility and scientific value of a Trojan tour and rendezvous mission.

The transfer trajectory followed by a spacecraft between …

Optimization And Design For Heavy Lift Launch Vehicles, Paul Andreas Ritter

Masters Theses

The simulation and evaluation of an orbital launch vehicle requires consideration of numerous factors. These factors include, but are not limited to the propulsion system, aerodynamic effects, rotation of the earth, oblateness, and gravity. A trajectory simulation that considers these different factors is generated by a code developed for this thesis titled Trajectories for Heavy-lift Evaluation and Optimization (THEO). THEO is a validated trajectory simulation code with the ability to model numerous launch configurations. THEO also has the capability to provide the means for an optimization objective. Optimization of a launch vehicle can be specified in terms of many different …

Development And Analysis Of Onboard Translunar Injection Targeting Algorithms, Phillippe Lyles Winters Reed

Masters Theses

Several targeting algorithms are developed and analyzed for possible future use onboard a spacecraft. Each targeter is designed to determine the appropriate propulsive burn for translunar injection to obtain desired orbital parameters upon arrival at the moon. Primary design objectives are to minimize the computational requirements for each algorithm but also to ensure reasonable accuracy, so that the algorithm’s errors do not force the craft to conduct large mid-course corrections. Several levels of accuracy for dynamical models are explored, the convergence range and speed of each algorithm are compared, and the possible benefits of the Broyden and trust-region targeters are …