Space Threat Detection

Design of Constellations for Monitoring Potential Threats from Meteors to Interstellar Objects

Earth is constantly bombarded with material from space. Most of these materials end up being dust grains that litter the surface of Earth, but larger bodies are known to impact every few decades. The most recent large impact was the Chelyabinsk meteor whose airburst set off a 500 ktons explosion. This was 40 times that of the Hiroshima nuclear explosion. Apart from meteors, there is a growing threat of space assets deorbiting. It is critical to have a constellation of satellites to autonomously lookout for space threats such as meteors and reentering space debris. Additionally, the recent observation of interstellar objects, ‘Oumuamua, and Borisov cross the solar system opened new opportunities for planetary science and planetary defense. There is a need to be cognizant especially if such interstellar objects pass by the Earth of potential dangers of impact. Specifically, ‘Oumuamua, was detected after its perihelion when it passed by the Earth at around 0.2 AU, with an estimated excess speed of 60 km/s relative to the Earth. Without enough forewarning time, a collision at such high-speeds can potentially wipe-out an entire planet like earth. Such challenges underscore the importance of detection and exploration systems to study these interstellar visitors.