The 6555th, Chapter III, Section 2
The 6555th, Chapter III, Section 2
The Eastern Test Range also changed to meet new ballistic missile program requirements. Though the SNARK and NAVAHO prompted expansion of the Eastern Test Range to Ascension Island in the mid-1950s, those winged missiles were not destined to become the principal users of the Range's most distant outposts. After what appeared to be a slow start, ballistic missile programs took root at the Cape and quickly dominated the Range after 1957. At the beginning of 1956, the Eastern Test Range extended from Cape Canaveral to the instrumentation station at Mayaguez, Puerto Rico -- a distance of approximately 1,000 miles. In addition to facilities at the Cape and Mayaguez, range stations were located near Jupiter, Florida, on the islands of Grand Bahama, Eleuthera, San Salvador, Mayaguana and Grand Turk. Instrumentation consisted of telemetry receiving stations, radar tracking sites, optical systems, command/destruct equipment, timing systems, communications stations and various types of recording equipment. Ascension Island had just been selected as the terminal point for a 5,000 nautical mile range, and St. Lucia and Fernando de Noronha were selected as intermediate stepping stones in the instrumentation chain a little later on. Picket ships were also required to fill in the gaps between St. Lucia, Fernando de Noronha and Ascension. While operations involving the MATADOR, BOMARC, SNARK, NAVAHO, the X-17 and the Army's JUPITER were underway at the Cape in 1956, preparations continued for the missile programs that would dominate the Range toward the end of the 1950s -- the Air Force's THOR, ATLAS, and TITAN, and the Navy's POLARIS.8
MAIN BASE, GRAND BAHAMA ISLAND
SAN SALVADOR - 1954
 | CENTRAL CONTROL BUILDING, GRAND TURK |
MAIN BASE, ASCENSION - April 1959
 | FIVE RANGE INSTRUMENTATION SHIPS IN WET STORAGE AT TRINIDAD ISLAND - 1958 |
SIDE VIEW OF THE RANGE SHIP ROSE KNOT - 1958
RACKS OF TELEMETRY EQUIPMENT ABOARD A RANGE SHIP - 1958
In general, all missile test programs had certain requirements in common. Sensors in the launch area were arrayed to gather data on high angle and low angle launches during the developmental phase of each missile program. That instrumentation measured the missile's position, velocity, acceleration, altitude and attitude to verify stability and control characteristics as the missile lifted off the pad. Most missile test programs could use the same instrumentation, though it might have to be rearranged or reconfigured to meet specific test requirements (e.g., picket ships and optical sensors). However, unlike aerodynamic "cruise" missiles, ballistic missiles had critical staging sequences when rocket engines shut down and booster segments dropped off. During those portions of the flight, a high degree of tracking accuracy was required for ballistic missiles. Near the end of a flight, data requirements tended toward higher accuracies for winged and ballistic missiles alike: winged missiles encountered stability problems during their terminal dives, and ballistic missile reentry vehicles coped with the stresses of reentering the atmosphere. In both instances, contractors needed very precise information on those events. On the whole, ballistic missile programs required a more sophisticated range, but many sensors procured for aerodynamic missile tests also served ballistic missile programs in later years.9
The Range was equipped with single-point radars initially. Those radars were called "MOD I" radars, because they were derived from the old SCR-584 radar system. The MOD I was the most economical solution to aerodynamic missile test requirements, but the AZUSA continuous wave tracking system was introduced in the mid-1950s to meet more stringent ballistic missile test requirements. MOD I and AZUSA radars had a distinct advantage over Doppler Velocity and Position (DOVAP) radars in that they required a minimum number of radar sites and operating crews. The increased emphasis on ballistic missiles and their higher accuracy requirements forced the Range to upgrade its radars around the middle of the 1950s, and the MOD I radars were replaced with MOD II S-Band radars supplied by the Reeves Instrument Company. Those, in turn, were replaced by FPS-16, radars at Patrick, Cape Canaveral, Grand Bahama, San Salvador and Ascension in late 1950s and the early 1960s. Larger C-Band radars were added at Patrick, Grand Bahama, Grand Turk, Ascension and Merritt Island to support APOLLO and MINUTEMAN launches later on. Modifications to individual radars continued through the 1980s.10
 | RADAR DISH ABOARD RANGE SHIP |
By the end of 1957, the Range's optical systems included long-range tracking telescopes, cinetheodolite systems, infrared tracking equipment and ribbon-framed cameras in 16 mm, 35 mm and 70 mm formats. CZR-1 ribbon-framed cameras covered the missile during the first 1,000 feet of a launch, and cinetheodolites followed the flight out to about 20 miles. Wild BC-4 1958 ballistic cameras captured optical data beyond the tracking radars' beamwidths, and they also obtained time-position data for ballistic missile staging events and reentry phenomena. Long-range tracking telescopes provided coverage as far as 200 miles downrange, depending on the weather, air turbulence and the time of day. Infrared cameras tracked missiles in the dark.11
More than 60 percent of the test data obtained on a missile flight in the late 1950s was gathered by two types of telemetry systems: 1) the frequency modulation system (FM) and 2) the pulse duration modulation system (PDM/FM). Both radio-based systems provided information on the internal characteristics and performance of a missile in flight. While the PDM/FM transmitter was smaller and lighter than the FM transmitter (making it ideal for small missile applications), the FM system had better channel frequency response. There was a telemetry station on Grand Turk in 1956, and other telemetry sites were activated when stations were opened at Mayaguez, Antigua and Ascension in 1956 and 1957. Radio communications, a timing system and a submarine cable system also tied the Range's stations together to insure coordinated coverage of each missile's flight. The Range was operated and maintained for the Air Force by Pan American World Services and RCA from 1954 through most of the 1980s, and by Computer Sciences Raytheon and Pan Am from October 1988 onward.12
AZUSA ANTENNA FIELD - 1954
INFLATED ENCLOSURES FOR AZUSA ANTENNAS - 1954
 | MOD II RADAR DISH WITH CAMERA ATOP CENTRAL CONTROL BUILDING |
MOD II RADAR REMOTE CONTROL UNIT
MOD II RADAR EQUIPMENT VANS - 1956
MOD II RADAR CONSOLES - 1956
FPS-16 RADAR AT CAPE CANAVERAL - 1963
CZR-1 CAMERA AND MOUNT - 1960
80-INCH ZOOMAR ON MK45 MOUNT WITH 35 MM MITCHELL CAMERA - 1960
BC-4 BALLISTIC CAMERA - 1961
RECORDING OPTICAL TRACKING INSTRUMENT (ROTI) - 1958
INFRARED TRACKER MOUNTED ON FPS-16 RADAR - 1961
TLM-18 TELEMETRY TRACKER - 1961
60-FOOT TRACKING ANTENNA
The 6555th: Missile and Space Launches Through
1970
by Mark C. Cleary, Chief Historian
45 Space Wing Office of History
1201 Minuteman Ave, Patrick AFB, FL 32925