Space Surveillance Sensors: Millimeter Wave (MMW) Radar (June 19, 2012)

Millimeter Wave (MMW) Radar

The Millimeter Wave (MMW) radar is a Ka-band (35 GHz) and possibly W-Band (95 GHz) imaging radar at the Kwajalein Atoll on the Pacific. It is a collateral sensor in the Space Surveillance Network (SSN).  It has recently been upgraded to a 4 GHz bandwidth, giving it a range resolution of about six centimeters.  It is currently the highest resolution imaging radar in the SSN (although it will be surpassed by the W-band upgrade to the Haystack radar when this becomes operational, likely in 2013).   


Photograph from:


Ballistic Missile Defense: Aegis BMD Testing “Unexpected Energetic Event” (June 10, 2012)

More information has recently become available on the “Unexpected Energetic Event” that was apparently responsible for the failure of the first SM-3 Block IB intercept attempt (FTM-16) in September 2011.  The cause was a failure in the SM-3 interceptor’s third rocket stage motor.    Despite assurances that this component, which is common to both the IA and IB variants of the SM-3 interceptor, had performed successfully many times previously, it also apparently experienced an “anomaly” in its previous test (FTM-15, April 14, 2011, of an SM-3 IA) serious enough to temporarily halt deliveries of new interceptors.  In the most recent test, a May 2012 repeat of September’s failed intercept, the part of the third stage booster (the second pulse) that had failed previously was not used, and the interceptor hit its target.


 “Unexpected Energetic Event” during the FTM-16 intercept test, September 1, 2011.[1]


Ballistic Missile Defense: Power of X-Band Radars (June 4, 2012)

X-Band Radar Transmit/Receive (T/R) Modules

In order to estimate the capabilities of missile defense radars such as the AN/TPY-2s used both as Forward Based X-Band (FBX) radars and THAAD theater missile defense battery radars it is necessary to assess the power output of the radars.  There do not appear to be any public official numbers for the peak or average powers of these radars.  However, one can estimate these based on the peak and average powers of transmit/receive modules making up their antennas.  This post discusses and assesses these power outputs for the TPY-2 and other X-band missile defense radars (SBX, GBR-P).  In particular, it argues that the average power outputs of the modules are 6, 10 and 16 watts for the GBR-P, SBX, and TPY-2 radars respectively


Space Surveillance Sensors: Globus II Radar (June 1, 2012)

Globus II

The Globus II is a large X-band dish radar located at Vardo in northern Norway (70.37˚ N, 31.13˚ E).  It is a dedicated sensor in the SSN and is used for tracking deep space objects, including objects in geosynchronous orbits, and for wide-band imaging of space objects.

The Globus II overlooking the town of Vardo (photograph from: