“Frequently Asked Questions”. Space-Track.org. 2019年6月23日閲覧。 “10 centimeter diameter or "softball size" is the typical minimum size object that current sensors can track and 18 SPCS maintains in the catalog.”
“Frequently Asked Questions”. Space-Track.org. 2019年7月14日閲覧。 “Q: What criteria are used to determine whether an orbiting object should receive a catalogue number and International Designation? A: We must be able to determine who it belongs to, what launch it correlates to, and the object must be able to be maintained (tracked well).”
