# Enhanced Kinetic Impactor for Deflecting Large Potentially Hazardous Asteroids via Maneuvering Space Rocks

## TL;DR

The paper proposes the Enhanced Kinetic Impactor (EKI), a novel spacecraft-based method to deflect large potentially hazardous asteroids by collecting and maneuvering rocks from a near-Earth asteroid to impact and alter the PHA's trajectory.

## Contribution

It introduces the EKI concept, enabling larger impactors and greater deflection distances than traditional methods, overcoming ground launch limitations.

## Key findings

- EKI can deflect Apophis by increasing its minimum distance by 1,866.93 km.
- The mission duration is approximately 3.96 years with a propellant cost of 2.98 tons.
- Deflection distance is increased by an order of magnitude compared to classic impactors.

## Abstract

Asteroid impacts pose a major threat to all life on Earth. The age of the dinosaurs was abruptly ended by a 10-km-diameter asteroid. Currently, a nuclear device is the only means of deflecting large Potentially Hazardous Asteroids (PHAs) away from an Earth-impacting trajectory. The Enhanced Kinetic Impactor (EKI) concept is proposed to deflect large PHAs via maneuvering space rocks. First, an unmanned spacecraft is launched to rendezvous with an intermediate Near-Earth Asteroid (NEA). Then, more than one hundred tons of rocks are collected from the NEA as the EKI. The NEA can also be captured as the EKI if the NEA is very small. Finally, the EKI is maneuvered to impact the PHA at a high speed, resulting in a significant deflection of the PHA. For example, to deflect Apophis, as much as 200 t of rocks could be collected from a NEA as the EKI based on existing engineering capabilities. The EKI can produce a velocity increment (delta-v) of 39.81 mm/s in Apophis, thereby increasing the minimum geocentric distance during the close encounter in 2029 by 1,866.93 km. This mission can be completed in 3.96 years with a propellant cost of 2.98 t. Compared with a classic kinetic impactor, the deflection distance can be increased one order of magnitude. The EKI concept breaks through the limitation of the ground-based launch capability, which can significantly increase the mass of the impactor. We anticipate that our research will be a starting point for efficient planetary defense against large PHAs.

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Source: https://tomesphere.com/paper/1907.11087