Title: Near-Earth Asteroid Deflection Strategies
A variety of strategies have been proposed to deflect a near-Earth asteroid (NEA) from impacting the Earth, ranging from slow-push techniques (e.g., gravity tractor, ion beam deflection, and laser ablation) to impulsive techniques that impart a rapid momentum change (e.g., high-speed kinetic impactors and nuclear detonations). Altering the NEA’s trajectory early minimizes the required change in velocity (ΔV). This is particularly true for NEAs that are an immediate threat because the required ΔV can increase by several orders of magnitude during the final months before impact. Additionally, deflection strategies need to be effective against a wide range of physical characteristics. NEAs can range from friable carbonaceous objects to stony or mostly metallic, with vastly different porosity and structural integrity. Additionally, their surfaces may have regolith that can affect deflection efforts, particularly contacting and attaching to the object. Depending on the warning time available, techniques that do not require detailed knowledge of the NEAs physical characteristics are desirable, and methods that can deflect a NEA without contacting the surface may be advantageous. Ultimately, spacecraft capable of rapidly engaging a threat and/or delivering significant payloads are extremely beneficial, and several approaches for modifying the NEA’s orbit could be incorporated into a deflection strategy.
Dan Mazanek is a Senior Space Systems Engineer at NASA’s Langley Research Center (LaRC) with 25 years of experience in space mission and architecture formulation and conceptual design and sizing of human and robotic spacecraft. He graduated with a B.S. degree in Aerospace Engineering from Virginia Tech in 1989. He was the Comet/Asteroid Protection System (CAPS) Study lead under NASA’s Revolutionary Aerospace Systems Concepts (RASC) program in 2001-2002 and led the LaRC technical analyses and independent technical review of NASA’s 2006 Near-Earth Object Survey and Deflection Study. He is a technical expert and a leader in the field of human and robotic missions to small planetary bodies and has led multiple study efforts to investigate sending humans beyond low-Earth orbit, including the development of a Near-Earth Object (NEO) crewed mission concept in 2005 and the Mars-Phobos-Deimos Preliminary Destination Mission Concept Study in 2012. He is the NEO mission lead analyst at LaRC and serves as the Near-Earth Asteroid Destination Lead for NASA’s Human Spaceflight Architecture Team. He is currently leading analysis efforts for the Agency’s Asteroid Redirect Mission (ARM) option of robotically capturing a boulder from a large asteroid and returning it to cislunar space.
Curious about the NASA Asteroid Grand Challenge to “discover all asteroids that could threaten human populations and find out how to deal with them”? NASA is sponsoring a series of virtual seminars on the properties of Near Earth Asteroids (NEAs) and what is being done to learn more about the hazards and the opportunities they may pose for us here on Earth. The purpose is to inform interested astronomers (both amateur and professional), students, teachers, and others who are potentially interested in contributing to studies of NEAs. Each seminar will focus on some aspect of the asteroid population, how we discover and track NEAs, and what we need to know about them if we are ever required to change the orbit of a NEA that is an impact threat.
The seminar format will be a 40-minute talk by an asteroid expert followed by 20 minutes for questions from the audience. They will be broadcast over the Internet. The audience will watch, listen and post questions by Adobe Connect using an Internet connection and a web browser.