Kinetic Impactor
Space device that deliberately collides with an asteroid to modify its trajectory by transferring momentum.
≡Description
A kinetic impactor is a spacecraft or projectile designed to strike at high speed a small Solar System body, such as an asteroid or its satellite, with the aim of altering its orbit. It operates on the principle of conservation of linear momentum: upon impact, part of the impactor’s kinetic energy is transferred to the asteroid, generating a small but cumulative change in its orbital velocity. Typical designs include a rigid structure that protects the instruments until the moment of impact and, sometimes, an additional mass payload to maximize impulse transfer. Among its advantages are the absence of explosives and mechanical simplicity, although its effectiveness depends on the target’s size, impact velocity, and the asteroid’s composition, which can limit the precision of the displacement.
⏱History
The concept of using kinetic impacts for planetary defense emerged in the 1990s within asteroid‑mitigation studies. The first practical demonstration was carried out in 2022 with NASA’s DART (Double Asteroid Redirection Test) mission, which impacted the moon Dimorphos of the binary Didymos system.
⚙Uses
In planetary defense, kinetic impactors are the most direct tool for deflecting potentially hazardous objects before they enter a collision trajectory with Earth, offering a rapid and controllable solution. In scientific research, the impact generates debris and fragments that can be studied to understand the internal structure and composition of asteroids, providing valuable data for space mining and the planning of future missions.
✎Examples
During the DART mission, the impactor reached a speed of several kilometers per second and collided with Dimorphos, reducing its orbital period around Didymos by about 32 minutes, demonstrating that a single collision can produce a measurable displacement. In a future proposal, a spacecraft equipped with a larger‑mass impactor could strike an asteroid several hundred meters in diameter, generating a deviation sufficient to cause its close approach to Earth to occur several years after the maneuver.
•Related terms
Added to Glosarix after appearing in a Phys.org Espacio article published on November 12, 2026.
