Brian Kaplinger

GPU Accelerated 3-D Modeling and Simulation of a Blended Kinetic Impact and Nuclear Subsurface Explosion

This paper develops a modeling and simulation framework for determining mission effectiveness of a twobody Hypervelocity Asteroid Intercept Vehicle (HAIV). This HAIV concept has been being developed to overcome key difficulties in coupling energy from nuclear explosives to an asteroid target at high relative velocities of 5 30 km/s. It does so by blending the concepts of a kinetic impactor and a nuclear subsurface explosion to create successive impacts that mimic the behavior of a buried explosive, increasing energy coupling by an order of magnitude. To demonstrate this increase in effectiveness, this approach is simulated in a Smoothed Particle Hydrodynamics model adapted for high-speed, low-cost, implementation on Graphics Processing Units. An improved 3D simulation system is developed that includes improved neighbor finding for parallel calculations. Fidelity to an inhomogeneous, asymmetric target model is increased to allow for better damage prediction and shock localization. Statistical tracking of the resulting fragments is used to determine efficacy for a variety of nominal orbit conditions.

Preliminary Results for High-Fidelity Modeling and Simulation of Orbital Dispersion of Asteroids Disrupted by Nuclear Explosives

High-energy methods utilizing nuclear explosives can plausibly fragment and disperse a near-Earth object (NEO) rather than deect it from its orbit. Orbital dispersion simulation and analysis results show that fragmenting and dispersing a hazardous NEO could lower the total mass impacting the Earth. This could be benecial in situations where some impacting mass is inevitable, or where the resulting fragments will be small enough to burn up in Earth’s atmosphere. Recent hydrodynamic models of an asteroid fragmented and dispersed by nuclear subsurface explosions were used as input conditions for orbital prediction. Computational challenges are discussed, and a comparison of steadily more realistic models is presented. Upgrades made to previous models are discussed, as well as preliminary results for reentry modeling and impact location prediction. Critical parameters including burst-to-impact time and explosive yield are examined, with guidelines for determining in which situations a disruption (i.e., fragmentation and dispersion) of an NEO is desired.

GPU Accelerated Genetic Algorithm for Multiple Gravity-Assist and Impulsive V Maneuvers

A combination of multiple gravity-assist and impulsive V maneuvers are often utilized for interplanetary missions to outer planets, such as NASA’s Galileo and Cassini missions. Such complex interplanetary missions often require the optimization of more than 20 variables, making brute force and traditional NLP methods dicult, if not impossible. In this paper a genetic algorithm, which utilizes the computational power of modern GPUs, is developed to solve the problem of designing advanced mission. By using modern GPUs the computational burden for advanced mission designs can be drastically reduced over traditional CPU optimization programs, allowing the mission designer to explore multiple mission scenarios or other mission options.

Optical Navigation and Fuel-Efficient Orbit Control Around an Irregular-Shaped Asteroid

As space exploration missions become increasingly complex, there is a growing need for autonomous operation capabilities to support stringent mission requirements. For long-duration asteroid exploration missions, a key concern is how to reliably and efficiently keep the spacecraft around a target asteroid. Given the large distance from the Earth, ground commands for navigation and guidance cannot be issued in real time and are not a practical solution. Fuel-efficient feedback control can be used to stabilize an arbitrary orbit about an asteroid provided on-board estimates of the spacecraft’s position and velocity vectors with respect to the asteroid center of mass. This paper demonstrates fuel-efficient orbit control, and investigates methods to estimate these relative navigation state vectors using a combination of optical cameras and LIDAR technologies for an autonomous orbit control implementation.

High-Performance Computing for Optimal Disruption of Hazardous NEOs

This paper is concerned with the problem of developing high-performance computing approaches for optimal disruption analysis and design of near-Earth objects (NEOs). Past models of a hypervelocity impact fragmentation of an NEO are addressed, and applied to a 3D inhomogeneous asteroid model with randomly generated sections and material parameters. The effects of uncertainty in modeling behavior are examined for a penetrating explosive mission with a two-body spacecraft. Optimization of mission effectiveness design for this type of mission is discussed, with suggestions for a comparison in efficacy. The effects of the target orbit are analyzed by creating a parameterization in (a, e, i) space, sampled from statistics of the known NEO distribution. Characteristics of impacting orbits in this space are introduced, with correlations to the uncertainties in orbital tracking.