George Vardaxis

Asteroid Mission Design Software Tool for Planetary Defense Applications

As the number of identified potentially hazardous near-Earth asteroids increases, the ability to track their orbits and plan for deflection/disruption missions ceases to be a simple exercise but a necessity. There exist several software tools to perform trajectory and mission optimization, but they tend to only focus on the mission trajectory optimization. This paper presents the tools and architecture of the Asteroid Deflection Research Center’s Asteroid Mission Design Software Tool (AMiDST), taking into account the mission launch configuration, target aquisition, the postencounter trajectory of the object, and mission cost estimation. Using AMiDST two mission examples are examined for asteroids 1999 RQ36 and 2011 AG5, as well as the trajectory tracking of Apophis, to demonstrate the capabilities of this tool.

Impact Risk Assessment of a Fragmented Asteroid in Earth Resonant Orbits

Taking advantage of direct numerical simulation, analytic keyhole theory, B-plane mapping, and planetary encounter geometry are shown to be useful in determining the impact probability of an asteroid with the Earth on a given encounter, as well as the potential for future encounters. The accurate estimation of the impact probability of hazardous asteroids is extremely important for space mission planning in order to mitigate their impact threat to Earth. Asteroids in Earth’s resonant orbits are particularly troublesome because of the continuous threat they pose in the future. Expanding upon the established theory, a computational method is developed to estimate the impact probability of an asteroid, fragmented into many pieces by a disruption mission, on their current and future encounters with Earth.