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By the turn of the century, the evolution of more potent U. S. and Soviet space systems is bound to have a profound effect on naval war-fighting capabilities, and, consequently, on the maritime strategy.1 The following investigates some of those future satellite capabilities, the natural constraints that orbital mechanics puts on satellite operations, and some of the changes that future space systems may bring to naval war fighting.
The production time for naval weapons that will emerge in the late 1990s exceeds a decade. Therefore, naval decision makers must ensure now that future satellite capabilities will mesh with those naval forces currently in planning in order to produce the optimum fighting “mix” of undersea, surface, air, and space systems that will most effectively execute future maritime strategy. But two “moving targets” affect planning—evolving satellite capabilities and weapons technologies—each of which will profoundly influence the maritime strategy. Planning is further complicated by the fact that satellites are still untried in global combat. Because of these factors, the challenge is to develop the means to judge the value of satellites against other naval assets and decide how extensively to incorporate space systems into future naval warfare.
The Constraints of Orbital Mechanics_________
The speed and direction of a satellite cannot be changed as easily as an aircraft’s, and enormous amounts of energy are required to accomplish seemingly trivial changes in a satellite’s altitude or orbital inclination. Satellites usually travel in one of four different types of orbits:
► Low earth orbits are generally circular, with inclinations that vary between 0 and 90° at altitudes from 200 to 3,000 nautical miles (nm) above the earth. These satellite8 are typically above any local horizon for 10 to 24 minute8 during each passage (they pass more quickly in lower orbits), and they can observe a region of one to several thousand nautical miles from nadir.2 Low-altitude satellite8 have the best resolution, but they provide only spot coverage and are more vulnerable to attack or disturbance.
► Sun synchronous orbits, a subclass of low earth orbit8' are retrograde, with inclinations that usually lie between 96 and 101°.3 They are useful for a periodic observation at the same sun angle.
► Molniya orbits have high inclinations and high eccen
tricities.4 Satellites in these orbits have altitudes that var^ from about 350 nm at perigee to 21,500 nm at apogee- These orbits are oriented in order for the satellite to spen a large amount of time over the latitude at which the sate lite service is needed. Their uses include communication8 at polar and other high latitudes. .
► Geosynchronous orbits have a mean altitude of 19,3"' nm above the earth and a period that is exactly the lengtn of one rotation of the earth—24 hours. As seen from th earth, a satellite in this orbit will remain near one long1 tude in the sky, although it may slowly wander in latituo through a “figure eight,” depending on the satellite’s m clination. If its inclination is 0° (always over the earth 8 equator), then the satellite is called “geostationary” b® cause for all points on earth its altitude and azimuth not vary with time. Geosynchronous orbits are used monitoring global weather and for communicating acro8S the hemisphere among groups of transmitters and receiv ers that are located at latitudes less than 70°.
Characteristics of Satellites that Apply to Naval Warftff
► The lower the satellite’s altitude, the quicker its passagj- will be over a sea target, and the higher its resolution be, but the more vulnerable it will be to attack from 1 e ground.
► When a satellite passes nearly overhead, it can observe the ship longer, resolve it better, determine its activity with higher confidence, and locate its position with greatef accuracy.
► Sets of geosynchronous satellites provide broad hem1
sphere coverage and worldwide connectivity for all but the extreme northern and southern latitudes. They offer relia ble, clear communications between terrestrial antenna8 that have elevations of more than 10°, and permit t e transfer of information across large distances (e.g-, tween Chicago and the Horn of Africa). A satellite in a Molniya orbit provides continuous coverage at a givelj northerly latitude for about ten hours per day, but at lea8 three such satellites, spaced along the orbit, are required to ensure that coverage at all times. .
► It is more difficult for antennas on a moving, rolling ship to track information downlinked from a moving sate lite than it is ashore. This difficulty increases as highe frequencies, with narrower beam widths, are employe0'
► Satellites in orbits that are too close to the earth are
'ckly eliminated by atmospheric drag. Without assis- nQCe to stay in orbit, satellites at altitudes of 150 nm last the tn°re l^an three weeks; at altitudes of about 300 nm, y last a year; and at altitudes of at least 375 nm, they ^ remain in orbit longer than several years.
]jtlnce the earth is rotating on its axis beneath the satel- ljt0rhit which remains fixed in space, low orbiting satel- s£s do not repeat their ground tracks in successive pas- ^ges around the earth; each successive pass slips to the ^tward about 22° to 25° of longitude. This factor may Se serious gaps in coverage that can only be addressed by adding more satellites of the same type to the space system.
► Satellites at altitudes in the 200- to 600-nm range and that have inclinations in the 60 to 80° range pass over targets at latitudes greater than 45° about twice as often as targets near the equator. If naval operations are expected to occur within a certain range of latitudes, satellite systems should be launched into orbits that have inclinations in the same range. The maximum latitude that the satellite will pass overhead is identical to the inclination of the satellite. Satellites with inclinations less than 40° will not
Figure 7: The ground track of LandSat 5, a low-orbiting sun-synchronous satellite, is shown, starting at the time of Figure 2 and ending 176 minutes later. Vertical ticks are given every ten minutes along the track. Track goes east to west with time, keeping up exactly with the westward progression of the sun.
overfly the Soviet Union because all latitudes in that cou try exceed 40°.
► Fewer satellites should be seen in the two altitude zon between 800 and 4,500 nm (two to five hours) and e tween 8,000 and 13,000 nm (8 to 18 hours) because thos^ are the regions of the Van Allen Belts where radiat'0 levels are detrimental to all but the hardiest of satellite ^
► For a low-orbiting six-satellite system at an incline 1 of 80°, the maximum daily gap in satellite coverage latitudes between 40° and 60° is about one hour. F°r same system, the maximum daily gap in satellite cover g
at latitudes in excess of 65° is about 30 to 45 minutes. This means that Soviet satellites with high inclinations in low earth orbit provide effective coverage of the northern sea aPproaches to the Soviet Union. The Soviets can achieve Vlrtually full-time coverage of U. S. maritime assets on all J*0rthern approach routes to the Soviet Union with any yPe of satellite system if the Soviets launch six to eight satellites of that type, equally spaced in orbits of high
Inclination.
. F°r four low-orbiting satellites in each of four planes in jocular orbits at an inclination of 60°, and with the satel- 1 es equally spaced in each plane, there is less than a °-hour gap at the equator, and the gap amounts to only j| °ut 45 minutes at higher latitudes.
The following considerations must be taken into ac- c°unt when assessing the best altitude at which to operate sPace system: receiver sensitivity, power, resolution, Caniera focal lengths, antenna size (gain), transmitter and eceiver bandwidths, noise background characteristics, asking considerations, sampling rates per day, ground ^Pced, swath width, and system vulnerability.
11 is important to keep in mind the effects of weather d geography on satellite operations. For obtaining im- gerY > the regions near the Mediterranean Sea and desert
Physical Disruption: Interception and negation, space mines, high energy lasers, and particle beam weapons.
Electromagnetic Disruption: Jamming and spoofing of both sensor and uplink, and electromagnetic pulses to disrupt satellite circuitry.
Dilution and Deception: Proliferation of satellites, false targets and decoy satellites, concealment of facilities, and mobility of launch and ground station assets.
Spacecraft Protection: Shielding and hardening, functional redundancy, on-board computing, sensor and uplink receiver electronic countermeasures, and uplink encryption.
Active Defense: Spacecraft shootback and maneuvering.
Reconstitution: Spare satellites in orbit and rapid launch of replacement satellites.
Attack/Defense of Command and Control (C2): Negate relay satellites, harden and defend ground facilities, attack C2 nodes, provide C2 path redundancy, and provide autonomy of operation.
► In a future war, satellites will be targeted with priorities that are in direct proportion to their threat. In general, the most cost-effective means will be used. Jamming, deception, and terrestrially based lasers directed toward satellite
reas are clear most of the time, while the North Atlantic a Western Europe are often cloudy. In addition, the dhern summer has many more hours of daylight than Horthem winter.
When choosing the best space system to accomplish a en task, satellite vulnerabilities and disruption/defen- e actions must be considered. Marked improvements
are
anticipated in the following areas as satellites slowly
^ake the transition from support systems to weapons sys
(thp CQtnp trancitir\n airr\1 'innc marlp Kptu;ppn 1 Q 1 4
ana
(the same transition airplanes made between 1914
sensors should be expected, because these methods are inexpensive and employ reusable resources.
Influence of Future Satellites on Naval Warfare
Contribution to the Growing Complexity of Battle: Satellites will be used to extend the “battle space” of battle groups and to aid in pinpointing the location of enemy forces. The nature of land and sea warfare in the nuclear era dictates that future weapons platforms will group themselves into dispersed, but coordinated fighting pockets that are simultaneously on the offense and the defense. Communications satellites will aid in the coordination of these forces, with the forces becoming more dependent on them the farther the forces are separated from each other and from their homeland. The number, type, or quality of threats to naval forces that have been cued by space- collected information will increase. These threats may include new submarine capabilities and tactics, increasing use of drones, extensions of the outer air battle, the use of longer range, land-based aircraft at sea, the employment of cruise missiles with increasing range, the presence of more sophisticated acquisition, tracking, and terminal guidance sensors, and more sophisticated mine warfare.
There will be a requirement for more timely information assimilation and decision making, and an increasing demand to coordinate assets to assure an optimum defense- In addition, the “battle space” surrounding all naval platforms must be redefined and extended beyond present limits. That battle space must extend to space. .
Timeliness and Prevalence: Satellites equipped wit suitable electromagnetic sensors, combined with the ability to send collected, near real-time information directly to nearby weapons platforms will have a profound impact on fleet operations. The fleet will be better serviced by the satellite’s information, but it will become increasingly more difficult to hide from an adversary’s space-base sensors.
Large numbers of satellites per constellation, differen constellations performing varying functions, and the abi' ity to fuse and crosslink information collected by satellite systems with those collected by aircraft and other assets will enable the satellites to locate the positions of surface ships in real time if conditions are right. This information will feed into familiar weapons that can then be used in a variety of ways. For example, the combination of timely information and the advent of more sophisticated terrmna guidance sensor systems in missiles will increasingly sug
Future Satellite Capabilities
Surveillance Satellites
Imagery Satellites: NASA has already flown a Large Format Camera with a ten-meter resolution on the shuttle.1 Using that camera in clear weather in the daytime, one should be able to type and identify small frigatesized combatants at sea, if the satellite is positioned so that its field of view includes them.
Infrared Satellites: The resolution, on average, is three times worse than imagery satellites. In clear weather, and probably in less than ideal lighting conditions, these satellites should be able to type and identify small combatants at sea, again provided the satellite’s field of view can be positioned to include them.
Multispectral Satellites: The French have flown SPOT, a multispectral satellite with a ten-meter resolution, which is now available commercially.2 This class of satellites should have the same ship identification capabilities as the imagery and infrared satellites. It would have the added capability of a far infrared detector, which could corroborate the identification made at other wavelengths, although it would probably not have the capability to type and identify independently. The ability of these types of satellites to detect changes in landscape and to identify different types of terrain from space can aid naval force projections from sea to land.
Signals Collections Satellites
At 400 megahertz (MHz) ultra-high frequency, the Argos satellite in circular orbit at an altitude of 460 nautical miles (nm) can now detect and track a bird-borne transmitter that radiates only one watt, and it can locate the transmitter to within one nautical mile.3 The example illustrates that strict emission control is needed at sea, because satellites located in low earth orbit can detect less than a few watts output from sea-based emitters.
Radar Satellites _______ -
Radar satellites must be placed in very low earth orbit, because the power received by a radar receiver drops off as the fourth power of the distance between the transmitter and the receiver- Therefore, physics dictates that the distance from transmitter to target should be minimized. However, radar satellites still need to operate at altitudes hig enough to overcome atmospherlC
drag. Thus, larger-than-normal
on-board fuel capacity and larg on-board power sources will be required to permit them to opef' ate properly. These types of sat ellites should be able to locate large warships, regardless of cloud cover.
Weather Satellites_______
Weather satellites only need to track large-scale atmospheric
the use of land-based missiles against sea targets, his will necessitate the development of new types of fleet Senses that will meet incoming missile threats, much as he Aegis system has been built to meet the current air-to- Sea and surface threats.
Data directly downlinked from satellites will shorten the h^e from detection to targeting. The increasing sophistication of threats will give a decided advantage to the side can strike effectively first.6 This situation increases incentive for both sides to use satellites for indications
that
the
and warning and for the determination of status of forces and order of battle in a crisis.
. Requirement for Increased Global Coordination: The Increasing range of weapons and the growing ability to use em quickly and accurately will require better and more me|y coordination of forces, much of which will be car- r'ch out by communications and relay satellites. Future H’arfare, driven by the increased range of weaponry and . 'gher mobility of war-fighting platforms, will increas- !n§ly compel weapons platforms toward mutually supportIVe roles, regardless of their location. This new era of j||utual platform support, prompted by weapons with unger range lethality, will have an impact on the way our aval forces will fight in the future. The Navy emphasizes emission control (EmCon) procedures, training for command, and the need for independence and personal initiative during periods of relative isolation at sea. Therefore, if there is ever a breakdown in command-and-control communications, the Navy is probably better prepared than any other service to carry out its mission without timely communications.
Soviet Defensive Satellite Networks and Threats to the Fleet: By the time naval forces would be preparing to execute the maritime strategy, defensive sets of Soviet satellite systems would probably be deployed that would be evenly distributed in orbits at inclinations of 50° or more. Inclinations between 70° and 80° would be especially useful to the Soviets for defense since low-orbiting satellites in these orbits will make long, sweeping passes along the maritime approaches to their northern ports from the Norwegian and Barents seas. With six to eight satellites in any given constellation, plus the possibility of several constellations being used for different purposes, the approaching battle forces will be almost continuously in one or more footprints while the satellites are simultaneously in direct line of sight to their ground stations in the Soviet Union.
The Soviets’ situation in their Pacific approaches is less optimum for the Soviet defense. Their major military
features and thus require resolutions of about one nautical mile. Existing weather satellites already have this capability. For polar region coverage, satellites in high inclination orbits will give satisfactory coverage, while for the lower latitudes, satellites in geostationary orbit are satisfactory.4 Revisit times only need to be as long as the time interval within which the positions of major cloud formations can be effectively predicted for military purposes. Three or four geostationary satellites positioned around the globe and a group of two to four high inclination satellites should meet most requirements. Improvements toward the real-time determination of sea surface winds, wave heights, sea surface temperatures, and ice thickness are expected when instruments like scatterometers, altimeters, and microwave radiometers are combined on future spacecraft.
Navigation Satellites
Ships at sea in World War II could only be located accurately
to about ten nm. Now, the Navy’s TRANSIT satellites can locate ships accurately to less than 0.1 nm. After NavSTAR/ global positioning system (GPS) becomes operational, accuracies of better than 60 feet are anticipated, thus improving navigational capability by another factor of 10. This overall improvement in accuracy from World War II to the GPS era exceeds 1,000 in linear distance.5 But the real improvement is in area location or a factor of about one million times the improvement in the ship’s ability to determine its location at sea as well as the location of potential targets through differential offsetting techniques. Ships will be able to rendezvous, maneuver, and navigate with minimum communications in all weather conditions using the GPS satellites. Moreover, all ships and most targets will have their locations expressed on a common grid, further improving warfighting potential. The Soviets will have a similar capability with their GLONASS navigation satellite system. Modern war
The Soviets have the only operational antisatellite system. It destroys a satellite with a conventional warhead that demolishes the target with a multi-pellet blast.
bases are at lower latitudes (below 60°), the collection of information must take place over vast stretches of water, and the satellites are farther from the homeland after collection. While not an impossible situation, it makes the acquisition, coverage, collection, and relay of information more difficult than in the northwestern sea approaches. At latitudes below 60° in the North Atlantic or below 50° in the North Pacific, there is much open sea to cover and it is more costly for the Soviets to ensure the same ‘ ‘completeness factor” that they can achieve at the more northern latitudes. The average threat is farther from the Soviet Union in the Pacific, however—a situation that probably leads to a somewhat lower threshold of concern.
The Mediterranean Sea has a relatively narrow east- west orientation south of 40° latitude. The Soviets will probably rely on information picked up by periodic sweeps of the region by their high inclination satellites fused with other collateral information obtained by sea and air assets.
Since a six-satellite system in circular, low earth orbit at
80° inclination produces maximum gaps of only 30 to 45 minutes at latitudes above 65°, ships under way at 3 knots will travel a maximum of only about 15 to 25 nautical miles before they are once again picked up by the next satellite pass with the same type of sensor. The addition o
type. Geosynchronous satellites
planners are just now recognizing this phenomenal improvement, and we can expect significant changes in naval strategy and tactics as a result of the improvements when these new space systems become operational. Precision timekeeping has also improved a millionfold since World War II. Recognizing the remarkable improvements in positioning and timekeeping, modern planners of naval tactics will be able to assist dispersed air, sea, and ground forces to mass, strike, and redisperse quickly using well-timed precision movements, a strong requirement in the nuclear age.
Communications Satellites
Communications satellites are designed to carry voice and data transmissions between ground terminals, with the satellite used as a one-hop ‘‘bent pipe.” They typically appear in orbits of the geosynchronous and Molniya- equipped with two- to six-meter diameter antennas and conventional receivers provide global communications connectivity over a span of latitudes from the equator to about 70°. Satellites in highly inclined orbits with high eccentricities (e.g., Mol- niya-type orbits) provide connectivity at high latitudes, including the polar regions. Continued growth in global communications via satellite is anticipated, with increasing numbers of mobile ground sites and the development and refinement of survivability enhancements.
Relay Satellites
Relay satellites are designed to transfer information between two orbiting bodies or between an orbiting body and a ground user. They receive signals transmitted to them from other satellites or from ground-, air-, or sea-based transmitters and relay those signals to other satellites or to ground-, air-, or sea-based receivers. Their use will permit rapid, multi-hop, worldwide transfer of two-way strategic and tactical information without having to rely on ground-based relays that involve extensive rout
ing complexity and nodal vulnerability. Future use of relay satellites will provide multiple paths for strategic long-haul communications. They promise to deliver important strategic >n' formation to shooters in nearreal time and to offer a valuable channel for delivering battle damage assessments to policymakers. The time between collection of information and its use by naval decision makers and tactical commanders will be reduced from hours to minutes.
This improvement in timeliness, operating in conjunction with the down linking of information from satellites directly to tactical commanders, will have a profound impact on the necessity for more rapid human decision making, in battle group targeting and on the ability of surface naval forces to hide or maneuver without detection.
Antisatellite Weapons
An expendable launch vehicle or an aircraft can place an antisatellite weapon into orbit where it could intercept a target
different satellite systems with different sensors will quickly fill
even those coverage gaps, especially if the jtystenis are mutually cued. Fleet vulnerability will then . Irige on such factors as the weather and time of day (for ‘Waging satellites), the ability to defeat the satellites by Jamming, deception, or direct attack, the condition of mCon, timeliness of information relay, and the effective's °f its use by the defense, and the technological sophistication of Soviet terminal guidance sensors for ac- |Ulring, tracking, locking onto, and guiding into a target.
Set of difficult-to-jam radar satellites would prove insuable to either side because they are not susceptible to Weather and EmCon conditions.
Launch Site Vulnerabilities and Space System Endur- auce; The usual scenario depicts a Warsaw Pact invasion . Western Europe that causes the United States to counter with its allies on land, supported by naval pressure on e flanks. Once the surprise stage is over, NATO allies pressure the United States to escalate the conflict by ■’hiking deep in the enemy’s rear, if not the enemy’s home- hud itself, to buy time by slowing down the enemy’s advance. NATO may also want any approaching U. S. and WTO navai components to strike bases in the Soviet °uieland to interrupt the land advance, further pressuring
Soviet decision makers.7 Each NATO country will view this exchange as an “even” trade—their homeland versus the Soviet homeland.
This scenario is not at all symmetric. The tradeoffs are not even. The asymmetry arises if no attack has yet been made on the North American continent. The real challenge to the United States will be to find ways to counter and abort any Soviet attack on Europe by using combined NATO strength in such a way that the probability that the Soviets will attack the North American continent is minimized. Thus, the United States will find it almost impossible to counter Soviet satellites by attacking their launch sites without assuming the escalatory burden of a major Soviet attack on North America. Then, since both the United States and the Soviet Union launch satellites from their respective homelands, either party may not make strikes on homeland launch sites early in a conflict.
The Soviets launch more satellites than the United States and their satellite lifetimes are much shorter. To maintain their high peacetime launch rates, they must have considerably more satellites of all types awaiting launch. With more satellites in storage, continual launches, and relatively invulnerable launch sites, the Soviets most likely will be able to reconstitute their satellite systems
Sellite and destroy it. Beyond ,*s direct physical kill mecha- n'sni, a wjjg spectrum of other ^satellite weapons such as lasers> directed energy weapons, and jamming procedures, may c used against satellites from e ground or from space.
^aned Satellites
The usefulness of putting a ^'litary man jn Space has been j’henuously debated. Man’s abil- T to make preplanned observa- l0ns to check out proofs of conCept and to test instrumentation hich will eventually fly in an , nWanned mode is apparent, o\vever. A manned space sta- °u in wartime has been ques- °ned primarily because orbital echanics do not permit a one- ^ 'a'kind, low-orbiting station to e over any given area when Inquired. Such a station in 'gher, perhaps geostationary, rrbit would not have the proper ^solution to be effective and °uld still be vulnerable to jam- lng and other electronics °Untermeasures. A multisatellite unned system for space-based
|L command and control is probably too costly—at least until man has a vehicle that can leave the station to perform reconnaissance much as an aircraft now operates from a carrier.
Perhaps the most appropriate naval application of a manned satellite system would derive from its use as a well-instrumented, multiservice, space- based reconnaissance team. This manned team in orbit could be tasked by an all-source, ground- based, multiservice intelligence node into which the status of forces throughout the world is fed and maintained. The ground node could cue the manned system, and task it to check the status of forces worldwide. It could then operate as an information collector. In addition, the manned space system could function independently to spot air-, ground-, and sea-based activity, and feed the ground-based node, and perhaps the tactical commander, with collateral information on the activities of enemy and friendly forces. If a more maneuverable manned system should become available in the future, it would probably be used by all the services.
'A ten-meter resolution means that two point sources of equal intensity that contrast with the background in brightness can only be separately distinguished if they are ten meters apart in a direction perpendicular to the line of sight. 2The commercial costs of multispectral products of the French SPOT and U. S. Landsat satellites (30-meter resolution) are in the price range of $200 to $ 1,750 for photographs and up to $3,300 for a computer compatible tape. ’Thomas E. Strikwerda, Harold D. Black,
N. Levanon, and Paul W. Howey, The Bird Borne Transmitter. Johns Hopkins Applied Physics Laboratory (APL) Technical Digest 6. No.l. 60 (ca. 1985).
JThe inclination of an orbit is the angle between its orbital plane and the earth's equatorial plane. Thus, i = 0° means that the orbital plane is coincident with the equatorial plane and i = 90° means that the orbital plane of the satellite travels over the North and South Poles during every revolution. Inclinations greater than 90° mean that the satellite is in a retrograde orbit, travelling around the earth in a direction opposite to the earth's rotation.
5The NavSTAR/GPS is a new Global Positioning Satellite System consisting of 18 active satellites in orbit, any four of which will be able to give three-dimensional fixes in position to military accuracies of better than 60 feet.
1 he Soviets are developing a similar system called GLON ASS, aGlobal Navigation Satellite System. "Molniya-type orbits (derived from the Russian word meaning “lightning”) were first used by the Soviets because antennas located in the Soviet far north cannot readily access satellites in the geostationary orbit without experiencing unacceptable signal attenuation.
W. E. Howard III
What Would Mahan Say About Space Power?
Alfred Thayer Mahan concluded that sea power could enhance U. S. power and prestige as it had for Great Britain. At a time when the U. S. Navy’s principal missions were coastal defense and raiding commerce, Mahan developed a philosophy of sea power that won recognition and acceptance far outside naval circles.
If Mahan were alive today, he would most likely point out that control of space will be equally as important as the control of the seas has been in enhancing the power and prestige of any dominant world power. He would probably base his argument on the fact that the nation that controls space will ultimately see and hear almost everything that transpires around the world. He might also explain that all targets in the atmosphere or on the earth’s surface are only 200 to 400 kilometers from platforms in low earth orbit. A missile could travel as little as 200 kilometers and sink an enemy ship or destroy an airplane or surface target unless they were properly protected by antisatellite (ASAT) weapons. Currently, 350-nautical-mile ranges are typical for antiship cruise missiles and 1,500 nautical miles for comparable land- attack weapons.
Another advantage of controlling space is that, although the platforms in orbit might have limited maneuvering capability, they have almost infinite range. Once the initial energy is expended to launch a system into orbit, no additional energy is required to maintain the same
speed for months, years, or even decades.
Control of space, like control of the seas, depends on more than mere physical presence. Mahan wrote about blockading
ports that provided access to the seas. Similarly, it is possible to blockade the gateways to space—the space ports. Three of the current major space ports are vulnerable to blockade by sea: Cape Kennedy, Vandenberg Air Force Base, and Kapustin Yar, the Soviet space port on the Volga River. Hostile ships equipped with surface-to-air missiles or sprint-type interceptors could effectively blockade both of our launch sites. A similar ship in the northeastern
The blockade of these space ports is predicated first on control of the seas in the vicinity of these facilities and also on con-
comer of the Black Sea could negate the Soviet launch facility-
trol of the sea lines of communl cation to these regions. Therefore, in order to secure unimpeded access to space, we must retain control of the ocean5 around these launch sites.
However, while both of our space ports are vulnerable to blockade from the sea, the two busiest Soviet Kosmodrotnes, Plesetsk and Tyuratam, are land-locked and cannot be blockaded in the classical sense, short of a land invasion. The Soviets have a clear advantage-
rapidly under crisis or wartime conditions. Their endurance is expected to exceed that of the United States, and, if there is attrition in the numbers of satellites on either side, the Soviet space systems may be able to outlast the U. S. systems in a conflict, unless the United States is much more effective in negating their satellites.
A Possible Satellite Solution to High Ground in ^,L Outer Air Battle: A zone of about 1,400 nm surrounds a battle group. Within this zone, various naval units have varying responsibilities for reconnaissance and defense- Close-in, organic assets can maintain an effective survei lance and air defense. The “outer air battle” should occur
The access to space is also aot without its equivalent narrow seas.” Any satellite aunched in any direction from 8>ven location will pass over a P°mt directly on the opposite
Plesetsk, Tyuratam, and Kapustin Yar all fall into the southern part of the Pacific Ocean (see Figure 1). These three regions are too far from land for air coverage. The corresponding points for Cape Kennedy and Vandenberg Air Force Base are in the southern parts of the Indian Ocean (see Figure 2). Therefore, the United States can only guarantee its access to space by both securing our launch facilities and gaining control of the locations in the
■ 1(k of the earth after completes the first half of its orbit. •Actually, the precise location is g 'Shtly off-set by rotation of the ^arth in 45 minutes, typical for satellite in low earth orbit plus aaneuvering, if any.) Control of eas opposite space launch fat 'ties could deny entry and exit • respective space programs ast as control of Gibraltar or ^ e ^traits of Hormuz could : eny entry and exit to some crit- Tal ports. The main difference s that Mahan’ s “narrow seas”
could be controlled from the shore, while the “narrow seas” of space can only be controlled from the oceans, at least for now.
The “narrow seas” for
__________ By Aadu Karemaa
Indian Ocean, which can only be achieved by naval forces. At the same time, the U. S. Navy can deny Soviet access to space from two or three locations in the southern Pacific.
The Soviet direct ascent coorbital ASAT weapon, commonly launched from Tyuratam, presents a new twist, however.
It is designed to destroy our space assets in low earth orbits, including some of our Navy satellites. Like other launches from Tyuratam, it must overfly the specific region in the South Pacific and, consequently, missiles from a sea-based platform could intercept it. Therefore, control of the sea in this area is also vital if we are to defend our satellites against Soviet co-orbital ASATs.
Mahan would probably have concluded with the observation that in the emerging space age, control of space will be the dominant element in the equation of global power, and that control of the seas will be more important than ever, since such control is necessary to guarantee our access to space or deny access to our enemies. Also, we can best defend our space assets from a few specific locations on the oceans as long as the Soviets maintain a co-orbital antisatellite capability.
Aadu Karemaa is the Manager of Advanced Antisatellite and Anti-ASAT Systems at the Space Systems Division of General Dynamics Corporation. He has a master of science degree in Aeronautical Engineering and is a 1980 graduate of the Army War College. He is also a commissioned officer in the Army Reserves.
eyond 800 nautical miles, which is the region in which an acking enemy force would now be engaged and within [elch future offensive forces against the fleet might re- ase many of their cruise missiles and other weapons tar- 7ed toward the battle group. The outer boundary of that ne will continue to increase. Aircraft must be tracked,
intercepted, and destroyed before they can launch their weapons. Yet, longer range weapons are causing the outer air battle zone to extend so far from the fleet that current organic assets may no longer be able to perform the necessary tracking and targeting tasks.
Concern about this eventuality has prompted a search
gence Agency as the Senior Intelligence Analyst for the Space Sys*e^, Division. In 1982, he worked with the congressional Office °f Tec ^ ^
for alternate nonorganic or organic assets to extend surveillance farther from the fleet. Inside the outer air battle zone, reconnaissance, attack, and interceptor aircraft must be densely deployed in order to locate and destroy enemy units with reasonable certainty. But, as the distance at which a weapon is lethal increases, the areas to be covered grow. This makes it very difficult to cover them effectively with organic assets. Ideally, a surveillance system should densely cover all air approaches to the true limits of the outer air battle, and also sample the air approach routes beyond the outer air battle zone at a rate sufficient to warn of intruders before they can release their weapons. The only solution to this surveillance problem is to place effective sensors high enough above the fleet to be able to anticipate the development of the battle and to give the warning time needed to be able to shoot down the enemy’s weapons platforms before they come within firing range of the fleet. There are three possible solutions to this problem: high-altitude aircraft (possibly unmanned), over-the- horizon radar installations, and satellites.
High-altitude aircraft are organic, reconstitutable, and can be controlled. They must be directed, however, and are vulnerable to attack immediately after detection, must be serviced by and duplicated for each fleet, and are difficult to deploy constantly, especially in bad weather. Over- the-horizon radars are land-based systems that will certainly contribute to surveillance capability, but cannot be counted upon to cover the critical battle areas. Their ability to detect ships and large aircraft will vary with the condition of the ionosphere which, in turn, depends on the weather, presence and strength of the aurora, the phase of the sunspot cycle, and the time of day.
Different types of satellites in mutually supportive constellations appear to offer the best long-term solution to the over-the-horizon detection and tracking problem. Satellite coverage is global. Coverage is a direct function of the number of satellites placed in the constellation. Satellite coverage can be designed to operate in a relatively non-cued condition. It takes time to attack satellites in orbit (especially if measures are taken to maneuver or harden them), and a single system will support all the naval forces around the globe. If it is a radar system, it offers the additional features of an all-weather asset that will operate effectively in darkness or in daylight against uncooperative targets.
Conclusion
It is tantalizing to think that a constellation of only about six to eight satellites of a given type will serve all battle groups in a non-cued mode, no matter where those forces are located. The average incremental cost of each type of satellite system is only about one-half a satellite per battle group, with 13 to 15 battle groups to be supported. While this cost is not small, it is equivalent to the cost of a few frigates, and it still may be less than the cost of equipping each battle group with a full set of surveillance assets to do the same job organically. We need to determine the optimum cost-effective mix of both satellites and organic assets that will work in mutual support to
accomplish future naval missions.
One of the current dilemmas the Navy faces is that commitment to a space fighting mix is not only costly, but, without spending even more on protecting a satellite constellation once it is in place, the space assets remain vu - nerable in wartime. Any commitment to space assets tna will be useful in wartime must be accompanied by a commitment to protect them.
U. S. naval planners must become more aware of the benefits that space systems can contribute to modern war fare. The Soviet Union is already well aware of them- your senior officers these questions: What can we do now- What can they do now? What are our relative strength5 and weaknesses? What is the threat today? What impi'°ve ments are being made to each of our capabilities? Then reflect on the questions: Who will be ahead in the year 2000 and why? How vulnerable are we, and where? HovV serious is it if we do not properly integrate space systems into naval warfare? Do we need space control as well aS air control for successful military operations? What trad offs of traditional naval assets must be made before space can take its place as a viable war-fighting asset?
Space systems can both help us and hurt us. If w should occur, we must be prepared to fight it with fun<( tional assets that measure up well against the adversary and not be left with capabilities that exist only on a draw ing board.
'See Adm. J. D. Watkins, USN (Ret.), “The Maritime Strategy,” U- Institute Proceedings, January 1986, pp. 2-17; Maj. H. K. O’Donnell, U “Northern Flank Maritime Offensive,” U. S. Naval Institute Proceeding*< tember 1985, pp. 42-57; C. S. Gray, “Maritime Strategy,” U. S. Naval I°stl Proceedings, February 1986, pp. 34-42. ^
2The satellite’s nadir is the point on the surface of the earth directly benea satellite. For a low orbiting satellite, the satellite’s nadir point travels along surface of the earth at a speed of about four nautical miles per second- 0f 3A retrograde orbit has an inclination of greater than 90° so that the direc revolution of the satellite about the earth is opposite to the direction of the ro of the earth on its axis. . 0f
^he eccentricity of an orbit is a measure of its shape. Technically, it is the ra ^ ^ the distance from the center of the ellipse to either focus divided by half °. .jy length of the major axis. A circular orbit has an eccentricity of zero, and a - eccentric orbit has an eccentricity of nearly one. afeSt
5The perigee and apogee are the points in an orbit where a satellite is at its ne and farthest points from the earth, respectively. , ^
‘The importance of an effective first strike in naval tactics is a recurrent ^ throughout the recent major work on naval tactics: See Capt. W. P. Hughes* USN (Ret.), Fleet Tactics: Theory and Tactics (Annapolis, MD: Naval I°s 1 Press, 1986). ^
7One should not rule out Soviet use of nuclear explosions at sea that would a ^ to take out one or more battle groups executing the maritime strategy, whlC ^ perceived as threatening the Soviet homeland. For a further discussion of nuC j. war at sea, see N. Polmar, “Nuclear War at Sea,” U. S. Naval Institute ProC ings, July 1986, pp. 111-113.
Dr. Howard is Technical Director for the Naval Space Command. being named to that position in 1985, he served with the Central Inj®^s
n oV
ogy Assessment. From 1977 to 1982, Dr. Howard served as Director^ the National Science Foundation’s Division of Astronomical Scienc' Between 1964 and 1977, at the National Radio Astronomy Observe* in Charlottesville, Virginia, and Green Bank, West Virginia, Dr. ard conducted scientific research and helped manage the observatory- was a Research Associate, Assistant, then Associate Professor of As . omy at the University of Michigan from 1959 to 1964. Dr. ^oVVjter received a PhD and a master’s degree from Harvard University a graduating from Rensselaer Polytechnic Institute in 1954.