Department of Defense Instruction 8581.01: Information Assurance (IA) Policy for Space Systems Used by the Department of Defense [open pdf - 128KB]
"This Instruction: A) Reissues DoD Directive (DoDD) 8581.1 (Reference (a)) as a DoD Instruction (DoDI) in accordance with the guidance in DoDI 5025.01 (Reference (b)) and the authority in DoDD 5144.1 (Reference (c)). B) Implements requirements of National Security Directive 42 (Reference (d)) by establishing IA policy and assigning responsibilities for all space systems used by the Department of Defense in accordance with Committee on National Security Systems Policy No. 12 (Reference (e)). C) Supplements IA policy and requirements contained in DoDD 8500.01E (Reference (f)) and DoDI 8500.2 (Reference (g))."
Defense Technical Information Center (DTIC): http://www.dtic.mil/dtic/