Applying centrifugal propulsion to enable asteroid deflection

To date, asteroid trajectory modification techniques employ the "big bang" approach. An impulsive deflection is imparted by slamming one or more high-speed kinetic impactor spacecraft into the object or by detonation of a nuclear device in its proximity. This is a "hit it once and hope for the best" approach. Instead of relying on this restrictive method, centrifugal propulsion offers an alternative, where a centrifuge and power supply land on a threatening asteroid to collect and incrementally project portions of the asteroid, using momentum transfer of the recoil to gradually adjust the trajectory away from Earth. This process sequentially allows "ejection, measurement, and repetition" to gradually fine-tune the trajectory needed for course correction. This offers flexible operation parameters that can be varied for convenience and optimization, including the location of the landing site, weight of each ejected payload, launch speed, direction, cadence, timing of successive ejections, and the relationship to the asteroid's velocity vector and spin axis. Once landed on an asteroid, the centrifugal system requires no consumables. Operating entirely on electrical power, it can operate indefinitely without additional support. This approach addresses aspects of Goal 3 of the 2018 U S. government's "National Near-Earth Object (NEO) Preparedness Strategy and Action Plan"-"Develop Technologies for NEO Deflection and Disruption Missions." The centrifuge approach adds a sustainable and repeatable slow-push tool to the planetary defense toolbox, mitigating the risk and uncertainty of single-impulse methods. An on-site centrifuge could deflect Chelyabinsk and Tunguska-sized asteroids to miss Earth within a few weeks' operation. The asteroid Bennu could be deflected in a few years of continuous spinner operation, depending upon the parameters chosen, which would be sufficient to eliminate a potential collision with Earth in the late 22nd century. The innovation of a self-contained power and kinetic launch capability without consumables opens new vistas for cost-effective asteroid deflection and other commercial, scientific, government, and international space missions.