The L5 Special Response Unit (SRU) is the counter-terrorism and emergency-intervention force with jurisdiction over the habitat cluster at the Earth–Moon L5 point. It is the body that averted the third detonation in the Coriopolis Bombing Crisis.

Remit#

The Unit exists because habitat security is unlike terrestrial security in one decisive respect: the pressure vessel is the jurisdiction. An event that would be a local disaster on a planet is, inside a rotating cylinder, a threat to the structural integrity on which every resident depends. The SRU’s mandate is accordingly weighted toward prevention and toward the physics of hull compromise rather than toward policing, which remains with the individual habitats’ own forces.

Its standing responsibilities include threat assessment against groups operating in the L5 region — the Gaia Preservation Front foremost among them — and the maintenance of structural simulation capability sufficient to predict how a given insult propagates through a given hull.

Engineering section#

That simulation capability proved decisive in 2118. The Unit’s engineering section maintains detailed seismic and structural models of every major habitat in the cluster, including the anisotropic wave propagation characteristic of a spinning pressurized shell, in which circumferential tension exceeds axial tension and wavefronts consequently travel several times faster around the cylinder than along it.

It was an engineering-section analysis that recognized the geometric relationship between the announced detonation sites and the seismic convergence zones they produced — and that the relationship was reciprocal, so that the convergence zones of the announced sites were themselves the locations of the devices. The insight located the third device in time for it to be neutralised.