What lessons can doctrines developed for land warfare offer for space operations? (Michigan National Guard photo by Sgt. 1st Class Jim Downen Jr.)

Terrain analysis for space warfare

by D. Grant Greffey
Monday, January 25, 2021

After reading a recent essay at The Space Review on space reconnaissance (see “From SSA to space recon: Setting the conditions to prevail in astrodynamic combat”, The Space Review, August 31, 2010), I found myself inspired to think about the challenges of intelligence preparation of the battlespace for space warfare. As a young cadet and then Infantry officer, I was taught the mnemonic OCOKA, which apparently was changed in Army field manuals some years ago to OAKOC. OAKOC stands for Observation and Fields of Fire, Avenues of Approach, Key and Decisive Terrain, Obstacles, and Cover and Concealment. Additionally, Weather is also a consideration for assessing the battlespace. This essay will attempt to apply the “OAKOC plus Weather” methodology in the space warfare domain, particularly for combat operations in Earth orbit.

Observation and fields of fire

For the most part, outer space provides almost limitless observation ranges and vast “fields” (volumes?) of fire for weapons. Indeed, the primary appeal of space-based platforms for military communications and reconnaissance is the fact that vast areas of the Earth can be communicated with or observed from space at any particular time. It is the ultimate “high ground.” And, as the orbits get higher, the greater the area of the Earth’s surface that can be seen (but at a loss of imagery resolution or signal strength.) For observing resident space objects, the challenge is more one of effective sensor range rather than obscuring terrain or weather events. A satellite at geosynchronous altitude is more than 35,000 kilometers from an Earthbound observer or telescope. Even satellites in a typical low Earth orbit (LEO) are hundreds of kilometers above the Earth’s surface. This is why military Earth-based Space Object Surveillance and Identification (SOSI) work is performed by large telescopes and powerful radars. Satellites are also used for Space Domain Awareness (SDA), but their effective sensor ranges are ultimately limited by the available mass and power of the spacecraft.

While fields of fire usually should be quite expansive in space warfare, the actual effective range of weapons may be limited by the ability of their operators to compute adequate fire control solutions because of the previously mentioned challenges in detecting and tracking space objects at long range.

Avenues of approach

In land warfare, Avenues of Approach represent likely paths for military units to traverse in the battlespace towards objectives. One of the key concepts here is one of “mobility corridors,” pathways for units to maneuver in a favorable fashion. Roads and open hard ground are advantageous for vehicles, while wooded or rough terrain would be advantageous for dismounted infantry. In space, the equivalent of mobility corridors would be advantageous trajectories to reach objective orbits or nodes. There seems to be no direct space warfare analog of the distinction between mounted and dismounted units. However, the preferred trajectory for an orbital maneuver would largely depend upon whether or not the maneuvering spacecraft is trying to optimize its fuel efficiency, its transit time, or its particular time of arrival at the new orbit. The first two goals can be addressed as purely a matter of engineering and physics. The third goal requires insight into the scheme of maneuver for the operative operational maneuver plan.

It also can be noted that choosing the location of space launch bases is predicated on the envisioned trajectories of the missions that need to be launched from those bases. The Plesetsk Cosmodrome in Russia is generally used for launches into high inclination orbits. Conversely, the Kourou launch site in French Guiana is highly useful for launching missions into low inclination orbits.

Key and decisive terrain

One of the peculiar features of space warfare is that the “terrain” is not necessarily stationary. In terrestrial warfare, natural terrain like forests, hills, mountains, and bodies of water don’t move about. This is also true of human-made terrain like buildings, roads, and bridges. In space, the natural terrain is composed of celestial bodies and their associated gravity fields. It can be argued that orbiting space stations can be considered “buildings,” but there is no space analog currently to bridges or roads.

For contemporary military space operations, the Earth itself is the dominant terrain as all other tactically significant objects orbit around it. Yet it is not truly stationary—it rotates about its axis (in addition to moving through the solar system). Therefore, unless a satellite is a perfectly geostationary orbit, the portions of the Earth visible to a satellite change constantly.

So, is there an analog to “Key Terrain” in space? Arguably, there is. In the GEO belt, certain nodes are important because of their corresponding fields of view. Certain other orbits offer their own advantages. For example, Sun-synchronous orbits allow imaging satellites, such as WorldView or TerraSAR-X, to pass over terrestrial locations at the same time of day consistently. Looking to the broader expanse of the Earth-Moon system (cislunar space), the Lagrange Points represent critical locales where armed platforms could dominate nearby space.

Obstacles

In near-Earth space, the Earth’s gravity represents the biggest obstacle to unhindered maneuver. The laws of Kepler and Newton are merciless in this regard, and gravity has an effect on any maneuver. Human-made space objects also can represent hazards to navigation because of the potentially catastrophic consequences of accidental collisions. It should also be noted that the debris created by kinetic attacks on spacecraft will result in new obstacles or hazards. Destroyed land combat vehicles, shot-down aircraft, and sunken ships remain stationary. But in space, spacecraft destroyed by kinetic effects and their associated debris will move and shift in accordance with the momentum imparted by spacecraft’s orbit, the physics of the fatal strike, and the effects of gravity.

Cover and concealment

There is scant protective cover in space, particularly in Earth orbit. For satellites concerned with terrestrial threats, the Earth itself provides perhaps the only meaningful cover from weapons fired from Earth. In land warfare, cover often limits the actual effective range of direct fire weapons by limiting the previously mentioned fields of fire. In space, the weapons may often have longer theoretical effective ranges than actual effective ranges because obtaining an adequate firing solution is too difficult.

The Earth also provides concealment from Earth-based sensors. This is where Kepler’s laws and the Earth’s rotation again work to the detriment of spacecraft survivability. A cagey infantry unit can stay safely hiding in the woods or behind a hill for a considerable amount of time. But with the exception of geosynchronous orbits, satellites eventually have to “break cover” versus observers or sensors positioned at suitable latitudes. It is at this point the reader should note that space terrain analysis should be applied to position terrestrial counterspace forces or anticipate where an adversary might deploy them. Indeed, the process of choosing sites for ground-based SOSI sensors or ground terminals for satellite uplinks and downlinks already consider optimizing clear fields of view for observation of, or communication with, satellites in particular orbits.

For precluding observation of a satellite from space-based sensors, again the Earth is an excellent source of cover and concealment. Even when a satellite is not behind the Earth in relation to a space-based sensor, clearly detecting and identifying that satellite is challenging against the backdrop of a sunlit Earth, especially with electro-optical sensors at high altitude orbits. The Sun and Moon also can confound electro-optical sensors in many situations, precluding detection and identification. Finally, a spacecraft operating in close proximity to other objects may get “lost” in the clutter when sensors attempt to observe it.

Weather

Most laymen do not appreciate that space has its own “weather.” The dominant source of space weather for the Earth is the Sun. Solar activity can create high-energy particle fluxes that pose problems for spacecraft. The shape, behavior, and status of the Earth’s magnetic field also impacts space operations. The famed South Atlantic Anomaly (SAA) has very real effects on space operations. (Then again, one could argue that the SAA represents a form of space terrain that is rough going, an obstacle, for spacecraft lacking proper hardening.) And even conventional terrestrial weather can have effects on space operations: clouds can adversely impact the performance of laser weapons as well as electro-optical telescopes used for space object tracking. Also, strong thunderstorms can degrade the performance of space-to-ground radiofrequency communications.

Conclusion

As the Space Capstone Publication Spacepower put it, “we must be fluent in Kepler and Clausewitz, Maxwell and Sun Tzu, Goddard and Corbett and Mahan, as well as Newton and Liddell Hart.” Space warfare doctrine is in its infancy, and space warfare professionals need to do some serious thinking about the peculiar nature of their warfare domain and the unique challenges it presents. The goal of this brief essay was to inspire discussion about how some particular theory and practice from the land warfare domain might be adaptable for application in space warfare. Let the discussions continue.

D. Grant Greffey is a contractor employee supporting the Survivability Assurance Office at the National Reconnaissance Office. The opinions in this article are his own.

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