Document created: 22 October 03
Air University Review, September-October 1973
Rockets and jets have become so commonplace today that scarcely a second glance is given a missile or satellite launch by people living near United States launch agencies. The writings of Jules Verne no longer command the awe or attention they did a few decades ago. Children’s games center around space-age technology as comfortably today as their fathers’ games centered around the gunfight at O.K. Corral. Television pictures from a roving lunar vehicle are accepted as casually as was Ed Sullivan’s second variety-show season.
And yet, despite this seemingly nonchalant acceptance of yesterday’s scientific impossibilities as today’s routine, some space-age “routine” is met with disbelief. So it is with the First Aerospace Control Squadron deep inside the Cheyenne Mountain complex of the North American Air Defense Command (NORAD), near Colorado Springs, Colorado.
Just entering NORAD’s underground hardened command facility inside Cheyenne Mountain leaves one deeply impressed if not overwhelmed. A miniature city consisting of eleven (soon to be fourteen) steel, spring-mounted buildings, it covers four and one-half acres. There are water and fuel reservoirs, medical and dental facilities, dining halls, and food supplies enough to operate more than 30 days while sealed off from the outside world behind giant 25-ton steel doors. All this has been carved out of solid granite. Impressive? Absolutely! But underground complexes are neither new nor space-age. What commands most attention and sticks in the visitor’s memory are the operational areas of the First Aerospace Control Squadron, nerve center of the Fourteenth Aerospace Force’s global space surveillance detection and warning sensor net.
The First Aerospace Control Squadron has three critical areas inside “The Mountain”: the Ballistic Missile Early Warning Center; the Space Defense Center, heart of the satellite detection and tracking net; and a computation center to support these two and drive visual displays for CINCNORAD, General Seth J. McKee.
The Early Warning Center has the most critical real-time response requirements. ICBM’s travel in excess of 16,000 mph and would take less than 30 minutes to go from their launch pads in Eurasian countries to impact selected target points in North America. Several foreign countries also have the technology required to place a weapon into an orbit around the earth and deorbit it to impact North American targets in its first earth revolution. Ballistic missiles launched from seagoing vessels require even less time from launch to impact. To provide accurate and timely warning of such events, detection equipment must be precise and rapid, communications must be fast and reliable, and human intervention by personnel in the Early Warning Center must be quick and sure to provide maximum warning time to allied forces.
The detection and warning equipment is precise and rapid. Missiles and satellite launches are detected within a few minutes of departure from their launch pads. Forward site equipment immediately begins processing the received launch indications to pinpoint exact time and location of lift-off and to calculate the heading of the launched vehicle. An over-the-horizon system blankets the Eurasian land mass with radiometric “eyes” that “see” around the curvature of the earth and report each satellite or missile as it penetrates the ionosphere. If the satellite or missile travels far enough to penetrate the Ballistic Missile Early Warning System (BMEWS) radars, which thrust beams of energy more than 2000 miles across the top of the world, it is again given the same close scrutiny to determine if it is a potential threat to North America. A similar process would begin immediately at sea-launched ballistic missile (SLBM) detection and warning system sensors for missiles launched from seagoing vessels off the coast of North America or in the Atlantic, Pacific, or Gulf of Mexico. In each case, the data are processed and ready for transmission to the NORAD Cheyenne Mountain complex within seconds of receipt.
The communications are fast and reliable. Direct, dedicated voice communications are available for virtually instantaneous contact between operators at the worldwide forward sites and the operators inside Cheyenne Mountain. Data circuits carry the processed information from detection and warning sensor computers with such rapidity that command authorities in Cheyenne Mountain, the Strategic Air Command, and the National Military Command Center are alerted and the data computed and displayed within seconds. Each circuit is engineered with as much designed-in reliability as possible. A built-in redundancy further increases reliability and survivability in the communications routes. BMEWS alone utilizes approximately 45,000 route miles in its communications links.
Early Warning Center personnel must be quick and sure. Missile warning officers and technicians must be intimately familiar with forward site equipment and capabilities. They must know their own processing and display equipment thoroughly so as to make accurate decisions and take immediate action almost instinctively. They have to react with time-piece precision. They must be judicious, analytical, even tempered, purposeful. And they are!
The satellite surveillance team in the Space Defense Center functions as the brain synapsis with the worldwide space sensors of the SPACETRACK and Space Detection and Tracking System (SPADATS); generates and maintains the catalog of all man-made objects in space; and gives analytical support to and interface with other scientific and space-age agencies.
The SPADATS network consists of electronic and optical sensors manned and operated by units of the United States Air Force, the United States Navy, and the Canadian forces. The largest contributor is the USAF SPACETRACK through the Fourteenth Aerospace Force, the space arm of the Aerospace Defense Command. The Fourteenth operates five radar sensors and four optical sensors, and Fourteenth units man and operate most of the missile detection and warning sensors.
The five radar sensors represent the established, reliable, and traditional methods of detection and tracking as well as the most sophisticated methods envisioned to date. Four units use updated versions of traditional radars that have proven reliable for many years. The U.S.S.R., for example, is under surveillance in selected areas from east to west by giant fans of energy stretching several thousand miles into space from detection radars that maintain a 24-hour-a-day watch for space launches. A second radar at each location, a large tracker, collects orbital data and performs space object identification (SOI). The so-called “black art of space,” SOI determines the physical and dynamical characteristics of orbiting space objects.
At Eglin Air Force Base, Florida, stands a giant single radar capable of performing both the detection and tracking radar functions concurrently. This is done by utilizing the most sophisticated methods of phased array radar. Unlike some stations that rely on teletype circuits for transmission of observational data to Cheyenne Mountain, Eglin has a direct dedicated data link from its computers to the Cheyenne Mountain computers. This data link insures that operators in the Space Defense Center have access to satellite observational data at virtually the same instant it is processed and presented to operators at the Eglin facility.
Four three-ton astrographic cameras are used by the optical units of the Fourteenth Aerospace Force for observation of those deep-space objects whose range and size make surveillance by radar sensors difficult or nearly impossible. Commonly known as Baker-Nunn cameras, these tracking devices circle the globe in their coverage of space. Locations range from the “down under” community of Mt John, New Zealand, to the cameras located in San Vito, Italy; Edwards AFB, California; and Sand Island southwest of Hawaii. Although limited to nighttime operations, this camera system provides such highly accurate satellite positional data that the limited observation time is more than adequate for maintaining quality element sets on deep-space objects, such as the Soviet Molniya communication satellites, which have apogees near 40,000 kilometers.
Historically, Air Force cameras have photographed certain satellites near apogee. The first Baker-Nunn camera photographed the first man-made earth satellite, Sputnik I, on the day it was launched, 4 October 1957. In 1958 AF cameras photographed Vanguard I, a 6-inch spherical satellite, at a height of more than 2500 miles, which is equivalent to photographing a shiny .30-caliber bullet in flight at a distance of 200 miles! Accuracy of the resultant observations, when the optical data are precision-reduced, in all cases surpasses that obtainable from any of the radars.
A fifth Baker-Nunn is operated by Canadian forces at Cold Lake, Canada, paralleling the operations of the four Fourteenth Aerospace Force optical trackers.
The U.S. Navy operates the Naval Space Surveillance System (NAVSPASUR), which is technically not a radar system but an interferometer. It employs a narrow “fence” of continuous wave radio energy stretching from the Atlantic at 65° West Longitude to the Pacific at 135° West Longitude and at approximately 33° North Latitude. The most significant contribution of this detection system is its ability to identify quickly the number of pieces associated with a launch or breakup, as was the case when a Titan IIIC rocket body exploded and produced more than 400 individual objects. This identification is important to NORAD, to keep track of all man-made objects in orbit and identify new satellites as quickly as possible.
Keeping books on all earth-orbiting man-made satellites is a key function in the generation and maintenance of a space catalog. The Space Defense Center uses data from cooperating sensors belonging to such agencies as the national Aeronautics and Space Administration (NASA) and the Smithsonian Astrophysical Observatory. Satellites are kept under surveillance throughout their in-orbit life by a set of mathematical parameters, which are updated as often as necessary to insure accuracy. The current set of parameters for each satellite is kept in Cheyenne Mountain for operational purposes. All outdated sets are kept at Ent AFB for historical purposes. Both current and historical parameters are but one support provided to military and civilian agencies having a bona fide requirement for satellite data.
The Space Defense Center keeps a close watch on satellite decay and close approach information. Decay information is provided through a computer program named TIP, for Tracking and Impact Prediction. Close approach information is provided through a computer program called COMBO, for Computation for Miss Between Orbits. With the highly sophisticated, special perturbations TIP program, Space Defense Center personnel analyze the decay trajectory of each satellite that has a possibility of surviving atmospheric re-entry and impacting the earth. Advance information is provided to a host of user agencies on the predicted impact area and time frame. Of course, most satellites analyzed through the TIP program do not survive re-entry. Even so, their spectacular celestial cremations have provided hardly less credence to science fiction than that lent by the few pieces which have survived re-entry and impact.
The COMBO program supports NASA in each manned space mission, from pre-launch to re-entry. Before the launch the proposed spacecraft trajectory is analyzed to determine if satellites already orbiting the earth pose any potential danger of collision with the manned spacecraft. As soon as the manned spacecraft goes into orbit, the orbital parameters are calculated and processed to see if there has been any change from pre-launch calculations. This process is constantly repeated, and the information is provided to NASA’s mission control throughout each mission. To date, NASA has not had to maneuver a manned spacecraft to avoid a collision with another satellite; however, Apollo astronauts have tracked passing satellites with COMBO calculations.
The Computational Center of the First Aerospace Control Squadron runs three computers 24 hours a day, performing some combination of 626,950 additions or subtractions, 199,400 multiplications, and 79,680 divisions each second to support the Space Defense Center. The second of the three computers is used full-time in storing and using as many as 32,768 computer words of 48 binary bits per word in core, plus up to 361 million alphanumeric characters on magnetic tape, in support of the Missile Warning Center and the processing/display system of NORAD Cheyenne Mountain Command Post. The third computer, standing at the ready to replace either of the other two at a moment’s notice, is kept busy supporting all areas of Cheyenne Mountain in their computational support needs. A fourth full-time on-line computer is dedicated to the Missile Warning Center, to insure continuous capability to provide maximum warning of ballistic missile attack on North America. In the near future even these machines will be reminders of the past as new computers are integrated into the worldwide command and control system.
The Computational Center provides personnel to operate on-line and off-line equipment used in support of all systems. Three computers are used to access the on-line computers by magnetic tape input and to act as backup input and output communications system for the Space Defense Center. A magnetic tape library stores backup tapes on hand, in the event of a malfunction that might render a primary tape inoperable, and keeps clean tapes for routine operations.
In spite of the apparent nonchalance of today’s space-age society, Space Defense Center visitors come out of Cheyenne Mountain blinking in the sunlight and a little staggered at all they have seen. The nerve center of the space age is a Buck Rogers descendant of the War Room strongholds of World War II.
Det 8, 14th Missile Warning Squadron (ADC)
Major Samuel C. Beamer (B.S., Florida State University) is Commander, Det 8, 14th Missile Warning Squadron, ADC, Laredo MTK, Texas. Commissioned from OTS in 1962, he has served in communications and electronic counter-countermeasures at Wadena AFS and Duluth Air Defense Sector, Minnesota; as Space Surveillance Officer, 12th Missile Warning Squadron (BMEWS), Thule AB, Greenland; and in the Space Defense Center, Hq NORAD.
Disclaimer
The conclusions and opinions expressed in this document are those of the author cultivated in the freedom of expression, academic environment of Air University. They do not reflect the official position of the U.S. Government, Department of Defense, the United States Air Force or the Air University.
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