ORBITAL MANOEUVRE DEFENCE, AVOIDANCE, CHASE: KEY CONCEPTS

An assessment list of United States Department of Defense current significant risks to space assets notes: ‘space-to-space orbital engagement systems’ [Rozpedowski, J. 2024 Every War is a Space War Now. Geopolitical Monitor (March 12)]. In Orbital Manoeuvre Defending Tactics, there are two different responses: (1) Orbital Manoeuvre Avoidance; (2) Giving a Satellite Defensive Capabilities.

(1) Orbital Manoeuvre Avoidance and Quasi-Positional Siting Theory

Orbital Manoeuvre is regarded as one of the, “Active measures … [including] … manoeuvring a satellite to avoid a co-orbital threat or hazard” [Ministry of Defence [United Kingdom]. 2022 Joint Doctrine Publication 0-40, UK Space Power. Ministry of Defence]. Orbital Manoeuvre is also dictated by Orbital Mechanics -

“Satellites move predictably according to the laws of orbital mechanics. These determine the parameters of an orbit, including the period (the time taken for one complete orbit), the satellite’s speed around the orbit and its track over the Earth.” [Ministry of Defence, 2022]

In Orbital Manoeuvre a satellite in one orbit (following the rotation of the Earth) can attack an opponent satellite in another orbit (also following the Earth’s rotation), by moving towards it (which is either to raise or lower its orbit), which also increases/decreases the craft’s speed in orbit: “For satellites … as altitudes become lower, the speed of the satellite relative to the ground increases.” [Drew, J.V. 2020 Space Operations: Lines, Zones, Options, and Dilemmas. Joint Forces Quarterly. Issue 99. 4th Quarter]

Quasi-Positional Siting in Relation to Orbital Warfare: “The nature of motion in space contributes to the global presence characteristic and also causes space forces to be quasi-positional rather than manoeuvring forces.” [Lupton, D.E. 1998 On Space Warfare. Air University Press] A 2021 formulation of Quasi-Positional Siting in relation to Orbital Warfare:

“Satellites in orbit – the best analogy is that they are like castles. We can predict where they are going to be. They are actually static in the Space Domain even though they are moving physically. It is when manoeuvre happens, and your energy configuration changes and how rapidly are you doing that and in what directions where we really start to talk about manoeuvre, and that makes things more difficult to track in the Space Domain. It provides more uncertainty for an adversary.” [Shaw, J.E. 2021 Emerging Space Warfighting Doctrine May Include Maneuver Warfare. Defense Daily (10 December]

The Quasi-Positional Siting thesis is based on the notion:

“Particularly at altitudes above major atmospheric effects, the unpowered motion of space vehicles is predictable for short periods of time (days or weeks, depending on the nature of the orbit). Given an observation of a space vehicle’s current position and velocity, trackers can accurately predict its position and velocity for days into the future by using the laws of physics. Therefore, unpowered space forces have more of the attributes of fixed fortifications whose position is known than of manoeuvring forces whose future position is in the mind of the commander. This is not to say that space vehicles cannot manoeuvre but that their manoeuvre is limited by the logistical problems involved in supplying them with fuel. In addition, most space forces cannot deviate significantly from their preferred orbit because their missions are predicated on covering particular areas of the Earth. Within the constraints of coverage requirements, future space forces will be able to exploit manoeuvrability as new technology ameliorates the fuel problem. Until then, they can best be described as quasi-positional forces.” [Lupton, 1998]

Quasi-Positional Siting is based on – ‘the Predictability of a satellite’s orbit from an adversary’s point of view, as it is possible to accurately predict where a satellite will be at a given time’ [Ministry of Defence, 2022]. Quasi-Positional Siting Theory is also expressed as Positional Space Operations [Shaw, J.E. Bourque, D.R. Shaw, M. 2023 Dynamic Space Operations: The New Sustained Space Maneuver Imperative. Æther: A Journal of Strategic Airpower & Spacepower. Volume 2. Special Edition (Winter)]. The Positional Space Operations paradigm, is where:

“the mission of a satellite drives the selection of its ‘parking spot’ on-orbit, and the satellite’s design, launch vehicle, and supporting infrastructure are tailored to the needs of attaining and maintaining this energy-constant position in an environment relatively free from Human-made threats. Satellites designed for these Positional Space Operations generally carry only enough propulsion to maintain their position and perhaps conduct a handful of low-energy strategic repositionings over the expected lifetime of the satellite.” [Shaw, 2023]

In the case of, “non-manoeuvrable satellites”, the Quasi-Positional Siting problem becomes more apparent as these cannot move from their orbit, “[as] …not all satellites can manoeuvre without disrupting their missions and therefore could have a ‘right-of-way’ over manoeuvrable spacecraft.” [Dickey, R. Wilson, J. 2023 Why There Should Not Be A Norm For “Minimum Safe Distance” Between Satellites. War on the Rocks (11 December)]

A contemporary response to Quasi-Positional Siting is the build-up of satellite numbers in Orbital Space creating constellations, which allow functions to be exchanged (in a type of Space shell-game with a potential adversary). Such as the concept –

“Disaggregated Constellations: Disaggregation is the separation of distinct missions onto different platforms or payloads, effectively breaking up multi-mission satellites into separate mission-specific satellites that operate in parallel.” [Harrison, T. Johnson, K. Young, M. 2021 Defense Against the Dark Arts in Space: Protecting Space Systems from Counterspace Weapons. A Report of the CSIS Aerospace Security Project. Rowman & Littlefield (February)]

Similarly, there can also be ‘Distributed or Proliferated Constellations’ [Harrison, 2021], this is where:

• Distributed Constellations use a number of nodes, working together, to perform the same mission or functions as a single node.

• Proliferated Constellations deploy a larger number of the same types of satellites to similar orbits to perform the same missions.

In terms of Quasi-Positional Siting theory even though the position of a satellite is known to a potential opponent, by relying on Disaggregated, Distributed, or Proliferated Constellations, the defence of these rely on ambiguity as to the role/function of satellites to protect these from a potential attack. This is because even though the position of a given satellite is known, the role/function it performs is being manoeuvred around several other satellites, and this makes a targeted attack difficult for an opponent to orchestrate, unless a larger attack is made with more Antisatellite Weapons, or an Area Weapon in Space Orbit is used.

(2) Giving a Satellite Defensive Capabilities: Satellite Fragility as a Tactical Concept

Giving a satellite defensive capabilities, is fundamentally underpinned by the notion of satellite fragility as a tactical concept. In 1958, it was conceived a battle between orbiting Human crewed satellites could result in one or the other, demolished or punctured with a missile fired into its orbit [Leavitt, W. Loosbrock, J.F. Skinner, R.M. Witze, C. 1958 The Space Frontier. Space Weapons: A Handbook of Military Astronautics. Air Force Magazine Volume 41. Number 3 (March)]. Conceptually, in the mid-to-late 1950s Human crewed satellite performing several rotations of the Earth, armed with missiles, or recoilless mechanisms that fired ‘space bullets’, was seen as possible given available technology. Another issue at play, was recognition that the extremes of the Space Environment, and that spacecraft-satellites would remain fragile. Fragility is a key constraint in developing satellite defence, or how a satellite can be built to defend itself from an attack. It should be noted that overcoming fragility, is regarded as one of the: “Passive measures …[to] … provide a significant level of protection by physically hardening satellites to enable resistance to radiation or electronic attack.” [Ministry of Defence, 2022]

(3) Orbital Chase

Characterizing Orbital Chase Tactics, it can be said: “space-to-space weapons are projectiles that chase targets through the heavens on paths dictated by the laws of orbital motion” [Lupton, 1998]. In a recent case of Orbital Chase, Russia in 2022 launched its satellite Kosmos-2558, which has frequently come close to a United States military satellite USA-326 [Krebs, G.D. 2024 Kosmos 2558. Gunter’s Space Page]. Russia’s satellite Kosmos-2558, has been characterized as having a, “satellite inspector mission” [Krebs, 2024]. Orbiting Earth in the same plane but at different speeds, as it is closer to Earth, Kosmos-2558 has been able to pass beneath USA-326 [Zak; A. 2024 Soyuz-2-1v Launches Military Satellite. Russian Space Web]. Kosmos-2558 when it was launched in August 2022 was placed in almost the same orbit as USA-326. Kosmos-2558 then performed an orbit-raising manoeuvre to reach an inclination of about 35 kilometres below USA-326. USA-326, is then said to have made its first jump to a higher orbit away from Kosmos-2558.

▼ Orbital Inclination Change is an Orbital Manoeuvre aimed at changing the inclination of a satellites’ orbit. The manoeuvre is also known as an Orbital Plane Change as the plane of the orbit is tipped. This manoeuvre requires a change in the orbital velocity vector (delta-v) at an orbital node: the point where the initial and desired orbits intersect, the line of orbital nodes is defined by the intersection of the two orbital planes. Inclination changes can take a very large amount of delta-v (fuel) to perform. In terms of Space Situation Mapping - “Altitude vs Inclination plots” are the two most important factors concerning orbital manoeuvring, and provide an essentially fixed map illustrating which space objects are close to each other, and could be potential threats [Szymanski, P.S. 2019 How to Fight and Win the Coming Space War. Strategic Studies Quarterly (Fall)].

Kosmos-2558 initially approached USA-326 for a close pass of about 30 kilometres on 7 April, but after the latter’s orbit change, the shortest distance between the two increased to 45 kilometres [Tingley, B. 2022 Pentagon Space Chief Condemns ‘Irresponsible’ Launch of Russian Inspector Satellite. Space.Com (19 August)]. In Orbital Chase Tactics, it can be argued due to the unique nature of Orbital Warfare: “a good space plan requires your adversaries to come at you, and use up their manoeuvring resources more so than yourself, allowing allied systems to perform more aggressive attacks later on” [Szymanski, 2019]. In essence, avoidance manoeuvres in Orbital Warfare grant unique advantages:

“During space conflicts you may decide to trade Orbital Space for time - in other words you may give up key orbits and manoeuvring room solely because it will take your adversaries some time to fill this void, or chase you down, or simply force … [them] … to use up valuable satellite fuel, while giving yourself more time to make better counter-attack preparations” [Szymanski, 2019].

Conversely, the same Chase-Avoidance Orbital Manoeuvre, can lead to a Chase-Down Tactic Scenario.