Gravitational perturbations correlated with the asteroid kinetic impact deflection technique

Abstract

This paper presents the use of the kinetic impact technique to deflect asteroids that may present some risk of collision with Earth. Within the work to be developed here, we intend to evaluate in more detail the possibility to deflect the orbit of the asteroid 101955 Bennu by applying variations in its velocity ($$\Delta$$ Δ v) at different positions along its orbital period and measuring effects of close encounters with planet Earth. We will see that, in a relatively long period of time, the asteroid has several close encounters with the planet, thus suffering a natural gravitational perturbation. With the application of the impulses, the relative distances change, causing variations in the energy of the asteroid and a large variation in the relative distance between the asteroid and Earth over a long period after the impulse. We present results related to the magnitude of the impulse applied, which is important because its defines the mass and velocity of the impactor to be considered. Then, we mapped the positions of the impulses along a period of the orbit of the asteroid. We finish by explaining what happens to the orbit of the asteroid during the periods of gravitational perturbation, since the close encounters amount to “Swing Bys” that intensify the variations of the relative distances between the bodies after the impulse is applied.

Deflecting an Asteroid on a Collision Course with Earth Using a Powered Swing-By Maneuver

“…The smallest distances found between asteroid and Earth within this period can be found in Figure 1, which work as Maps for Impulses in the Orbit of Asteroids (M.I.O.A.) [19]. In this figure we can see that by applying the 50 mm/s (blue) impulse to the mean asteroid anomaly of 352°, we get a collision with Earth.…”

“…The present paper uses the idea of the application of a small impulse in the asteroid using a collision of a spacecraft, but this impulse is applied near a previous passage by the Earth, before the one that may end in collision. The importance of a previous passage like this for deflecting the trajectory of the asteroid to avoid a collision with Earth was noted in [19], when performing general simulations. Therefore, the present paper is a sequence of this study and focus in the situation where the impulse is applied close to this previous passage, instead of well before the collision.…”