SATELLITE SAFE ZONE

‘Spherical Tactical Zone’: Broadly speaking there have been several iterations of classical Air Defense terminology used to define regions of space, around satellites in Orbital Space, which have unique warning and command and control responsibilities, such as: “Space Defense Identification Zones”, and, declared specific smaller tactical, “Close Attack Engagement Zones”, or larger encompassing, “Space Long Range Engagement Zones” [Szymanski, P.S. 2019 How to Fight and Win the Coming Space War. Strategic Studies Quarterly (Fall)]▼.

▲▲ In terms of Space Situation Mapping - “Displays that show thousands of space objects orbiting the Earth are not too useful for planning purposes.” [Szymanski, 2019] Whereas “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, 2019].

The basic concept of a Guardian-Bodyguard Satellite is these could be stationed near satellites that need protection. It is a technological solution mated with a political-diplomatic one – the concept of the Space Safety Zone. The Space Safety Zone is usually conceived as a three dimensional spherical zone in Space with the satellite it protects at its centre as it travels along its orbital path. A spherical zone of space is often considered, when looking at tactical vectors as these can come from any direction in Orbital Space. Commonly, “Operators do use spherical areas around a satellite to estimate the probability of collision at the closest point of a pass between objects” [Dickey, R. Wilson, J. 2023 Why There Should Not Be A Norm For “Minimum Safe Distance” Between Satellites. War on the Rocks (11 December)]. However, a criticism of the Space Safety Zone, notes:

“the problem is that there is no ‘sphere’ that would work well as a broadly applied norm for space safety or security. Because operators have a wide range of factors for what distance would give them concern, and because the physics of motion in Space don’t lead to spherical metrics for measuring risk, a spherical keep-out zone would simply not be effective as a universal metric for judging unsafe or threatening behavior.” [Dickey, 2023]

Space Safety Zone Size, which can be made-out around a critical but vulnerable satellite, has been suggested this could be a minimum safe distance of some 50 kilometres at Geosynchronous Orbits [Chow, B.G. 2020 Space Traffic Management in the New Space Age. Strategic Studies Quarterly (Winter)]. It is argued a Space Safety Zone would come into existence as internationally agreed, or between the United States and a coalition of countries, to a three dimensional area of Space around a satellite (that needs to be protected), that another craft cannot infringe without permission. Entry into the Zone, without permission, would be called-out internationally as a violation – which given suitable ground control monitoring, would be observable and verifiable [Chow, B.G. 2019 Two Ways to Ward-off Killer Spacecraft: One is Diplomatic; the Other, Technological. Defense One (30 July); Chow, B.G. Weeden, B. 2020 Securing Our Military Satellites Against Shadowing Spacecraft. Space Policy Workshop Panel II. Green, J. et al. Discussion Transcript (2 March)].

The question becomes what type of defence can be initiated, by a country, in order to protect its satellite. Guardian-Bodyguard Satellite would operate within the Space Safety Zone to protect the nearby satellite and dissuade an attacker from entering near the satellite under protection. Manoeuvring Guardian-Bodyguard Satellite (located within the Zone) could be used to interdict it, interposing itself between the attacker, and the target, or disabling the attacker once it enters the Zone. As a prelude to an intervention, Guardian-Bodyguard Satellite would have specific Rules of Engagement. Such as it would ‘announce to the world that an invader is in our zone and that it must leave immediately.’ [Chow, 2019; 2020] The next set of steps, are to use an impactor to gently nudge the attacker away, or to block its progress - this presumes Guardian-Bodyguard Satellite would be sufficiently robust, or have a shell/surface designed to absorb Space collisions with another craft. The object being to do no harm to the invader, and ‘push it out of the Zone without hurting it.’ [Chow, 2019; 2020]

Space Passive Defence Strategy: Effectively, a Space Passive Defence Strategy, is advocated underpinning Space Safety Zones. This has two parts: (1) its political-diplomatic aspects (the set-up of Space Safety Zones agreements); (2) potentially using Guardian-Bodyguard Satellite technology. However, when viewed from the paradigm of escalatory strategies, the most passive form of defence in Space involves:

“target satellites performing evasive manoeuvring, satellite hardening, and using resilient architecture for new satellite constellations, are far less escalatory than active defences such as … [Guardian-Bodyguard Satellite] … to prevent robotic Antisatellite Weapons from reaching our critical satellites.” [Chow, 2019]

In the case of the non-manoeuvrable kind of satellite these could be vulnerable, large, expensive and few-in-number legacy satellites, which the United States will continue to rely on at least during the 2020s [Chow, 2019]. Using a Guardian-Bodyguard Satellite in a Space Passive Defence Strategy, while having aggressive aspects, it nevertheless could be used, without aiming to destroy an attacker, ‘but to gently push offending satellites far enough away that they no longer violate agreed Space Safety Zones.’ [Chow, 2019; 2020]

Escalation and De-escalation: A fundamental aspect of a Space Passive Defence Strategy is its escalatory aspect and capacity for reversible acts. Guardian-Bodyguard Satellite could be armed; however, its laser, cyber and electronic warfare capabilities could be dialled-down operating only to temporarily disable an enemy craft. Another variation of a Space Passive Defence Strategy is agreement to treat certain classes of satellite as ‘off-limits’, such as the historical case that interference with surveillance-reconnaissance satellite dedicated to early warning, had the understanding it could trigger a nuclear counterstrike. International treaty arrangements have in the past carried such terms:

“The Accident Measures Agreement of 1971 and the Prevention of Nuclear War Agreement of 1973 together obligate the Soviet Union and the United States to refrain from interfering with or attacking early warning systems of either side, which would include satellites that are components of such warnings systems.” [Bosco, J.A. 1990 International Law Regarding Outer Space – An Overview. Journal of Air Law and Commerce. Volume 55. Issue 3]

A key criticism of the Space Safety Zone concept notes in regards to Rendezvous and Proximity Operations:

“Assumption: The People’s Liberation Army’s Geosynchronous Orbit satellites with robotic arms are a threat to ‘juicy targets’ like United States satellites that are not equipped with enough fuel to manoeuvre. Rebuttal: Many of the satellites can move enough to diminish the risk, while potentially staying on mission. Since at least 2010, the United States has equipped the military’s Geosynchronous Orbit communications satellites (SATCOM) like the Advanced Extremely High Frequency (AEHF) satellites with Hall thrusters that use some on-board gas, but mostly rely on solar power for collision avoidance. At least since the start of this decade, United States’ Missile Early Warning Satellites in Geosynchronous Orbit such as the Space Based Infrared System (SBIRS) satellites have also included Hall thrusters for position adjustment. Hall thrusters enable slight manoeuvres with much lower mass and fuel requirements. Given that Rendezvous and Proximity Operations require precise calculations, even the minor and slow adjustments of a Hall thruster would complicate any adversaries’ approach.” [Burke, K. 2024 PLA On-Orbit Satellite Logistics. China Aerospace Studies Institute (March)]

See Rendezvous and Proximity Operations.

KEY POINTS ABOUT ORBITAL WARFARE

Space Safety Zones, Spherical Tactical Zone, Escalation and De-escalation.