Orbital Shell

An orbital shell is the organising unit of the mega-constellation era: the set of satellites flying at one shared altitude and inclination, distributed across multiple orbital planes whose ascending nodes are spaced around the globe. Think of it as a spherical layer wrapped around Earth at a fixed height, populated evenly enough that from any point under it several satellites are always overhead. A full mega-constellation stacks several shells: lower-inclination shells concentrate capacity over the mid-latitudes where most customers live, while near-polar shells close coverage over high latitudes. Regulators licence constellations shell by shell — each is defined in filings by altitude, inclination, plane count and satellites per plane — and operators fill them methodically, launching batches into a plane, raising them to the shell's altitude, then phasing them into their slots. Shell design is a compromise machine: altitude trades coverage area per satellite against latency and post-mission decay time; inclination trades coverage geography against launch cost. Shells also matter for traffic management, since each one is effectively a dense population pinned at a single altitude — which is why regulators increasingly scrutinise how shells from rival constellations interleave, and why a few hundred kilometres of vertical separation between systems has become valuable orbital real estate.