Recent Missile Defense Agency (MDA) presentations at the August 2013 Space and Missile Defense Symposium suggest that boost phase defenses may be making something of a comeback at the MDA. This is somewhat surprising (to me), since in the last few years MDA has cancelled its two main boost program, the Kinetic Energy Interceptor in 2009 and the Airborne Laser in 2011.
However, a slide, shown below (click on it for a larger image), from MDA Director Vice Admiral J.D. Syring’s August 14 presentation showed an “Airborne Interceptor Layer” that was intended to provide “Highly mobile, survivable BMD; Autonomous and Integrated” as one of five MDA “Priority Technology Investments.”[1] Another priority investment area was high power lasers, with one objective being the development and deployment a new Airborne Laser.
Another slide, shown below, from the presentation of Richard Matlock, MDA’s Program Executive for Advanced Technology, shows both a “Boost Phase Kill” from a “High Altitude Long Endurance Platform” (apparently using a laser), and an “Airborne Weapons Layer,” deployed on a fighter aircraft.
[1]Slide 21 of VADM J. D. Syring, “Ballistic Missile Defense Overview,” 16th Annual Space and Missile Defense Symposium, August 14, 2013.
mostlymissiledefense 
Allen Thomson
/ August 21, 2013Also, the Common Kill Vehicle looks like it might be returning to the Multiple Kill Vehicle concept where >1 KVs are launched on a single booster/bus.
mostlymissiledefense
/ August 21, 2013Allen,
Yes that certainly seems to be the idea. It is hard (at least for me) to see how else the common kill vehicle concept makes sense, given the much different payload capacities of the GBI and navy interceptors.
George
Allen Thomson
/ August 21, 2013It puzzled me at the time that the MKV was dropped, because it at least seemed to be trying to address the distressingly intractable discrimination problem by circumventing it with a kill-them-all approach. Now maybe the M in MKV is so much smaller than the M in Multiple Nondiscriminable Targets that the concept wouldn’t work in practice, and that would have to be determined.
j_kies
/ August 30, 2013Sadly it appears the personnel that helped LTG O’Reilly savage the US Treasury via programs without appropriate scientific and engineering diligence are still with MDA. Dr Coyle nailed the underlying problems ID’ed by the DSB and the NAS/NRC in http://www.armscontrol.org/act/2013_01-02/Back-to-the-Drawing-Board-The-Need-for-Sound-Science-in-US-Missile-Defense
A modest read of the NAS/NRC findings could see the entire MDA ‘technology’ portfolio running contrary to the findings thus fodder for Sequestration bill-paying without loss to future capability.
At best Missile Defense is technically very hard, perhaps we ought to assure the science, architecture and engineering issues are competently addressed.