The standard answer is about $70 million each, but the actual cost is more like $90+ million. And the GBI unit acquisition cost, which includes development costs, is well in excess of $400 million each.
.A GBI being deployed into a silo at Fort Greely, February 2012 (Photograph source: www.mda.mil/global/images/system/gmd/DSC_5160.jpg).
Posted by mostlymissiledefense on July 24, 2012
https://mostlymissiledefense.com/2012/07/24/ballistic-missile-defense-how-much-does-a-gbi-interceptor-cost-july-24-2012/
The Haystack Auxiliary Radar (HAX) is a wideband radar located at the Lincoln Space Surveillance Complex near Boston, the same site as the Haystack imaging radar and the Millstone Hill tracking radar.[1] As a contributing sensor in the Space Surveillance Network (SSN) it is used for imaging near-earth orbit satellites, and it is also an important sensor for scientific studies aimed at characterizing the near-earth space debris environment.
HAX Radar Under Construction (image from: http://www.orbitaldebris.jsc.nasa.gov/measure/images/radar_dome.jpg)
Posted by mostlymissiledefense on July 21, 2012
https://mostlymissiledefense.com/2012/07/21/space-surveillance-sensors-haystack-auxiliary-radar-july-21-2012/
Recently, the missile defense-related issue I have been asked about most frequently (my dentist asked me a few days ago) is the effectiveness of Israel’s Iron Dome system against short range rockets launched from the Gaza Strip into southern Israel. Many recent press reports have cited engagement success rates as high as 90%, while other reports are as low as about 75%. My preliminary assessment based on the public literature (largely newspapers, which are often contradictory) is that that success rate is about 75%. I will update this assessment as I come across more information.
(Image source: http://www.rafael.co.il/marketing/SIP_STORAGE/FILES/6/946.pdf)
Posted by mostlymissiledefense on July 19, 2012
https://mostlymissiledefense.com/2012/07/19/ballistic-missile-defense-effectiveness-of-israels-iron-dome-system-july-19-2012/
The Wall Street Journal reported yesterday that an AN/TPY-2 X-band radar was being deployed to Qatar.[1] This is apparently the same radar as the one that the Missile Defense Agency’s August 2011 Program Update said would be deployed to the North Arabian Gulf by the end of 2011.[2]
An AN/TPY-2 radar temporarily deployed near Juneau Alaska for a missile defense test. The radar antenna is at far right. The two similarly colored units adjacent to it are for cooling and electronics. (Photo source: Missile Defense Agency)
Posted by mostlymissiledefense on July 18, 2012
https://mostlymissiledefense.com/2012/07/18/missile-defense-x-band-radar-to-qatar-july-18-2012/
The Precision Tracking Space System (PTSS) is, according to recent testimony by Missile Defense Agency (MDA) Director Lt. General Patrick O’Reilly, “the greatest potential future enhancement for both homeland and regional defense in the next ten years.”[1] PTSS is a system of satellites intended to track ballistic missiles using an infrared telescope with sufficient accuracy to be able to guide interceptors. The PTSS program was formally initiated last year as a replacement for the Space Tracking and Surveillance System (STSS) which was the latest in a long line of proposed space-based missile tracking systems dating back to at least the late 1980s. Two STSS “demonstration” satellites were launched in 2009, and the MDA recently noted that they had reached their 1,000th day in orbit and were still operational.[2]
PTSS Satellite (image from MDA factsheet)[3]
Posted by mostlymissiledefense on July 17, 2012
https://mostlymissiledefense.com/2012/07/17/missile-defense-can-the-precision-space-tracking-system-discriminate-july-17-2012/
mostlymissiledefense 
