Assessment of Long Range Laser Weapon Engagements: The Case of the Airborne Laser

Abstract

This article presents a method developed to assess laser Directed Energy Weapon engagements. This method applies physics-based models, which have been validated by experiments. It is used to assess the capabilities of the Airborne Laser (ABL), a system for boost phase missile defense purposes, which is in development under supervision of the U.S. missile defense agency. Implications for international security are presented.

The article begins with a general introduction to laser Directed Energy Weapons (DEW). It is notable that several laser directed energy weapon prototypes have recently become operational for testing. One of them is the ABL, a megawatt-class laser installed into a cargo aircraft. It is concluded that only the ABL could have significant political impact on an international scale at the moment. Hence, the remainder of the article focuses on the assessment of that system. The laser intensity, the induced temperature increase of a target and the impact of this temperature increase on the mechanical properties of the target are calculated for different scenarios. It is shown that the defensive capability of the ABL against ballistic missiles is limited. Even a successful laser engagement that deflects a missile trajectory from its intended target can have negative impact for third parties, as missile warheads will most likely not be destroyed.

ACKNOWLEDGEMENTS

The article extends work done by the Jan Stupl during his dissertation, ⁵² which was conducted at the Institute for Peace Research and Security Policy at the University of Hamburg, Germany (IFSH), the Institute of Laser and System Technologies at Hamburg University of Technology (iLAS) and the Institute of Experimental Physics (IEXP) at the University of Hamburg between 2005 and 2008. The dissertation was supervised by Prof. Hartwig Spitzer (IEXP), Prof. Claus Emmelmann (iLAS) and Prof. Götz Neuneck (IFSH), who is also author of this paper.

The authors wish to thank Prof. Hartwig Spitzer and Prof. Claus Emmelmann for their longtime extraordinary support during the dissertation project. iLAS provided the lab environment for most of the conducted experiments. Additional experiments were conducted at the Bremer Institut für angewandte Strahltechnik (BIAS) in Bremen, Germany. Jan Stupl wants the thank the members of iLAS for providing a highly stimulating work environment and lots of personal support. He is also grateful to the Interdisciplinary Research Group on Disarmament, Arms Control and Risk Technologies (IFAR) at the IFSH for their input on the security implications and their personal support, as well as the Carl Friedrich von Weizsäcker—Centre for Science and Peace Research at Hamburg University.

The authors want to thank Scott Flagg, Harvey Lynch, Dean Wilkening and the anonymous reviewers for their helpful comments on earlier drafts of this paper. The authors are also grateful to Jürgen Altmann, Geoffrey Forden, Kate Marvel and Pavel Podvig for useful discussions.

Jan Stupl wishes to thank the Center for International Security and Cooperation (CISAC) at Stanford University for providing a highly stimulating work environment and for supporting this work.

Notes

^athe cited source provided the approximation function.

^baccording to finishing on the inside and the outside.

^caccording to white paint or mid-qualtity aluminium surface at a wavelength λ = 1.315 μm.

^avalid 245 K to 813 K, approximation according to data points provided by Kaufman.