Frequently Asked Questions On Missile Defense

Q: What have been the manning requirements for the radar, both in maintenance mode and in calibration mode?
A: The total number of people used for maintenance and calibration (checking the health and status of the radar) operations at Kwajalein is ~3 to 6.  This number increases to >10 for test operations, with the additional personnel responsible for planning (preparing the computer program to instruct the radar to collect data on the test objects) and analysis (determining the information collected by the radar).  Contractor and government personnel are also in place at remote mission planning centers to provide additional support.

Q: What have been the site power requirements?
A: At Kwajalein, power was supplied by two dedicated 780 Amp lines, either of which was sufficient to power the entire facility.  Standard operations called for the antenna, processors, electronics, HVAC, and facility to utilize one line, drawing 90 Amps at 4160 Volts, 3-phase.  The antenna mount drive platform and controls utilized the other line, drawing 26 Amps at 4160 Volts, 3-phase.  The design included a breaker that could direct the entire system to either one of the two feeder lines upon failure of the other feeder.
 
Power for the radar if located at the Brdy site identified by the Czech government would come from a diesel-powered generating unit located within the secure perimeter of the radar facility.

Q: How was the radar cooled during operations, and does it continually take a large amount of water to cool as do lower frequency (or tube-driven) radars?
A:  A self-contained separate cooling unit (filled with a mixture of water and glycol) is used to cool the antenna. No external water or other external cooling process is used. The coolant is circulated through the organic cooling unit, where it is cooled by fans and is recycled, much as the radiator in a car functions.  Standard measures will be in place to prevent any environmental contamination in the unlikely event that any coolant leakage occurs. Replenishment and flushing are long term events, again much like a car’s radiator.
      
Q: What were the safety zones put in place for operations (both mission and non-mission)?
A: Safety zones were put in place for (a) aircraft on the ground, (b) aircraft in the air, and (c) ordnances or electro-explosive devices on military aircraft.  For operations at Kwajalein, the ranges associated with aircraft and ordnances were ~1.5, ~4, and ~13.5 km respectively.  In addition, no-fly zones are coordinated with air traffic control to ensure safe operation of the radar. There are no safety zones required for personnel on the ground because at no time is the radar energy allowed to come into contact with the ground.

Frequency control plans (both for the main beam and for grating lobes) are maintained by (a) exclusion zones, (b) minimum elevation limitation, (c) power density measurements, (d) redundant verification of safety, and (e) software design of the transmitter controls.

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