Question

1. who tracks the space debris and what is the smallest size an object has to be to be trackable?

Explanation:

Space debris tracking is mainly done by organizations like the United States Space Surveillance Network (SSN) and the European Space Agency's Space Debris Office. The smallest trackable size of a space object (debris) depends on factors like the tracking system's capabilities (radar, optical). Generally, for radar systems, objects as small as about 1 - 10 centimeters in low Earth orbit can be tracked (larger for higher orbits due to distance and signal attenuation), while optical systems can track larger, brighter objects or smaller ones with advanced telescopes under good conditions, but typically objects a few centimeters or more in size (with more precise systems tracking smaller, but this varies by technology and orbit).

Answer:

• Who tracks space debris? Organizations like the United States Space Surveillance Network (SSN), the European Space Agency (ESA)’s Space Debris Office, and other national space agencies (e.g., Russian, Chinese space tracking entities) track space debris. Commercial and academic entities also contribute to monitoring efforts.
• Smallest trackable size? For radar - based tracking (e.g., SSN radars), objects as small as ~1–10 centimeters in low Earth orbit (LEO) can be tracked (size increases with orbital altitude due to signal loss). Optical tracking systems (telescopes) typically track larger objects (or smaller, brighter ones), with a practical lower limit of a few centimeters (varies by telescope resolution, orbit, and object reflectivity).