Requirements and Feasibility for the Transition from a Ballistic Missile Capability to an Anti-Satellite (ASAT) Capability

Author data: 
Jaganath Sankaran
Publication Date: 
December 2007

CISSM Working Paper

Re-evaluating Space Security
The Reconsidering the Rules for Space Project
File Name: 
Document Type: 
Working Papers

     Ballistic missiles and anti-satellite (ASAT) weapons operate using similar technological means but not with the same level of technology or engineering maturity. ASATs require more sophisticated systems engineering and integration requirements to adapt to the challenges posed by an ASAT intercept. The main difficulties arise from the requirements for detection in space and the high closing velocities needed to execute an ASAT intercept. These difficulties have been underestimated after the recent Chinese ASAT test by those who have suggested that other nations could in the nearfuture master this technology gap and convert their primitive ballistic missile capabilities into an effective ASAT weapons capability.

     This report examines whether Iran could use its modest missile capability to project a viable ASAT threat to US Low-Earth Orbit (LEO) satellites. The study suggests that, even if Iran has an Intermediate Range Ballistic Missile (IRBM), it would not be easily able to leap-frog the technology gap from a ballistic missile to an ASAT capability. Unless it develops and tests the system vigorously and visibly, Iran would not project an ASAT threat.

     Chapter 1 of the report analyzes the capability of the Iranian Shahab-4 missile, including the velocity attained by the missile at an altitude of 1000 kilometers. Chapter 2 provides an analysis of the total thermal energyemitted by a model satellite in the Infrared (IR) band of interest for the given ASAT characteristics. Using the total thermal energy in the IR band, the detection range from which the ASAT can lock on to the satellite is determined. Chapter 3 details both, the ideal and real-time Proportional Navigation Guidance (PNG) law simulation performed using the parameters obtained in Chapters 1 and 2. The miss distances and acceleration requirements are shown graphically to capture the nuances and limits in the capability of an ASAT based on current Iranian technology level. The conclusion explains the limits and assumptions of this analysis and scope for further work.