Catherine S. Plesko

Multi-organization — Multi-discipline effort developing a mitigation concept for planetary defense

There have been significant recent efforts in addressing mitigation approaches to neutralize Potentially Hazardous Asteroids (PHA). One such research effort was performed in 2015 by an integrated, inter-disciplinary team of asteroid scientists, energy deposition modeling scientists, payload engineers, orbital dynamicist engineers, spacecraft discipline engineers, and systems / architecture engineers from NASAs Goddard Space Flight Center (GSFC) and the Department of Energy (DoE) / National Nuclear Security Administration (NNSA) laboratories (Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratories (LLNL) and Sandia National Laboratories). The study team collaborated with GSFCs Integrated Design Centers Mission Design Lab (MDL) which engaged a team of GSFC flight hardware discipline engineers to work with GSFC, LANL, and LLNL Near-Earth Asteroid (NEA)-related subject matter experts during a one-week intensive concept formulation study in an integrated concurrent engineering environment. This team has analyzed the first of several distinct study cases for a multi-year NASA research grant. This Case 1 study references the NEA named Bennu as the notional target due to the availability of a very detailed Design Reference Asteroid (DRA) model for its orbit and physical characteristics (courtesy of the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer [OSIRIS-REx] mission team). The research involved the formulation and optimization of spacecraft trajectories to intercept Bennu, overall mission and architecture concepts, and high-fidelity modeling of both kinetic impact (spacecraft collision to change a NEAs momentum and orbit) and nuclear detonation effects on Bennu, for purposes of deflecting Bennu.

An architecture for mitigating near earth object's impact to the earth

Near-Earth Objects (NEOs), like species extinction events, present a great threat to our home planet and human kind. The motivation of designing this architectural framework is the current lack of structured architecture for the process of detecting, characterizing and mitigating these NEO threats. Due to the recent establishment of the NASAs Planetary Defense Coordination Office (PDCO), it is critical to link the individual facilities conducting separate research with an objective of forming a clearly defined collaborative system based on data reporting and sharing. The architectural framework is designed for integrating the process of detecting, characterizing and mitigating NEO threats. The goal of designing the architecture is to organize current data and resources into useful information and correlate that information with the goals of the NEO mitigation study. The architectural framework will enable scientists, organizations, and decision makers to locate, identify and resolve semantic confusion, properties, facts, constraints and issues with potentially hazardous asteroids. Our major focus is to design the data and information flow that models the complete process from NEO detection, to designing the mitigation strategies. A secondary focus is to develop a system-of-systems architecture to describe the supporting infrastructure for the framework. The framework is also built with the opportunity to leverage future assets from the broader Planetary Defense (PD) community, and identify/speed up relevant PD research and response.i

Los Alamos and Lawrence Livermore National Laboratories Code-to-Code Comparison of Inter Lab Test Problem 1 for Asteroid Impact Hazard Mitigation

The NNSA Laboratories have entered into an interagency collaboration with the National Aeronautics and Space Administration (NASA) to explore strategies for prevention of Earth impacts by asteroids. Assessment of such strategies relies upon use of sophisticated multi-physics simulation codes. This document describes the task of verifying and cross-validating, between Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL), modeling capabilities and methods to be employed as part of the NNSA-NASA collaboration. The approach has been to develop a set of test problems and then to compare and contrast results obtained by use of a suite of codes, including MCNP, RAGE, Mercury, Ares, and Spheral. This document provides a short description of the codes, an overview of the idealized test problems, and discussion of the results for deflection by kinetic impactors and stand-off nuclear explosions.

Investigations of short warning time response options for hazardous near-Earth objects

This paper describes an assessment of capabilities for two planetary defense techniques: Kinetic Energy Impactors (KEIs) and Nuclear Explosive Devices (NEDs), including both Near Earth Asteroid (NEA) deflection and disruption. These studies will help us understand how energetic systems affect asteroidal (or cometary) bodies, and how to deliver energetic payloads to target objects under short warning time conditions, accounting for real-life constraints including payload integration and spacecraft lifecycle. Techniques for spacecraft trajectory optimization and mission design, scientific knowledge of asteroid and comet characteristics and chemistry, and energetic systems modeling will be combined to produce designs and strategies that will inform effective, reliable responses to short warning time NEA impact scenarios.

Challenges of Deflecting an Asteroid or Comet Nucleus with a Nuclear Burst

There are many natural disasters that humanity has to deal with over time. These include earthquakes, tsunamis, hurricanes, floods, asteroid strikes, and so on. Some of these disasters occur slowly enough that some advance warning is possible for affected areas. In this case, the response is to evacuate the affected area and deal with the damage later. The Katrina and Rita hurricane evacuations on the U.S. Gulf Coast in 2005 demonstrated the chaos that can result from such a response. In contrast with other natural disasters, it is likely that an asteroid or comet nucleus on a collision course with Earth will be detected with enough warning time to possibly deflect it away. Thanks to Near‐Earth Object (NEO) surveys, people are working towards a goal of cataloging at least 90% of all near‐Earth objects with diameters larger than ∼140 meters in the next fifteen years. The important question then, is how to mitigate the threat from an asteroid or comet nucleus found to be on a collision course with Earth. In...