What is the space domain? What are its boundaries?
While there is no internationally-recognized legal definition, the boundary that distinguishes space is generally accepted to begin at the Karman Line, at 100 kilometres altitude, and extend infinitely.
AFDN 1-19 Air-Space Integration – Doctrine
The Air Power and Space Power Centre has prepared this doctrine note to enable members to understand the fundamental benefits and constraints of using space effects to support ADF operations. I encourage you to read this doctrine note with a view to better understand your role in a space-enabled military organisation. Empower yourself to contribute to the thinking and concepts that are regularly being reviewed to assure that the current and future designs for Air Force will continue to reliably deliver the air and space power needed.