|
Descripción
|
|
|---|---|
| In this paper, a semi-analytical method to calculate impulsive asteroid deflection maneuvers is pre- sented. It can be applied to the design of any impulsive asteroid deflection mission, and is particularly useful when optimizing last-minute deflection by nuclear explosion as the optimum impulse direction can be far from tangential. The method hinges on minimizing the impulse size under a constraint on the b-plane coordinates. The optimization is based on a fast, semi-analytical algorithm developed for Low Earth Orbit optimal collision maneuvers design. Several deflection strategies can be selected following this algorithm. Additionally, an analysis of resonant returns and keyholes is performed, in order to detect and prevent deflecting the asteroid into an Earth-impacting orbit in the near future.. To method is applied to the fictitious asteroid 2017PDC. First we constrain the b-plane intersection point to be at a distance from the Earth center greater than a threshold. The minimum-impulse maneu- vers with varying anticipation show non-trivial properties. For integer multiples of the asteroid period, the optimal maneuver is purely prograde or retrograde. An increasing tendency, superimposed to peri- odic variations, can be observed on the required impulse size as the deflection is performed closer to the conjunction. The impulse size abruptly grows shortly before the conjunction. The optimal maneu- ver orientation may present discontinuities as the maneuver anticipation changes, and this will happen when different local optima exchange global optimality. We present a transfer maneuver that arrives to the asteroid about a whole orbit before the conjunction. For this case, we present a sensitivity analysis of the optimal deflection maneuver. We also compute the resonant circles corresponding to returns of the asteroid in up to 20 years after the 2027 encounter, and calculate to a first approximation the associated keyholes to evaluate and mitigate the risk of an impact in a subsequent encounter. Finally, we present a last-minute deflection strategy for a transfer maneuver that arrives months before the collision with Earth. We perform a geographical deflection, shifting the impact point on Earth surface from a densely populated area to a water body. We show evidence that the optimal impulse is far from tangential, and has an important out-of-plane component. | |
|
Internacional
|
Si |
|
Nombre congreso
|
Planetary Defense Conference 2017 |
|
Tipo de participación
|
960 |
|
Lugar del congreso
|
Tokyo, Japón |
|
Revisores
|
No |
|
ISBN o ISSN
|
|
|
DOI
|
|
|
Fecha inicio congreso
|
|
|
Fecha fin congreso
|
|
|
Desde la página
|
|
|
Hasta la página
|
|
|
Título de las actas
|
|