Replacement cadence

A fleet is never finished; it is a garden that needs constant replanting. Electronics wear out, radiation bites, nuclear batteries fade. Here is the drumbeat that follows: how many satellites die each year, and how fast a production line has to run to keep every station whole.

Each environment sets its own life expectancy. Six years inside Jupiter's radiation belts; twenty-five in the calm cold beyond Neptune, where the limit is the slow fade of nuclear power, not damage. And because the cruise to a far target takes years, its replacement must launch before the failure it answers: the factory always builds for the fleet as it will be, not as it is.

The dials

Build quality 1.0× design life

Slide right to imagine tougher satellites; every step stretches each environment's life expectancy.

Factory pace 150 satellites a year

replacements needed / year

launch rhythm

always in transit

Where the attrition happens

Environment	Satellites	Design life	Losses / year	Share of the drumbeat

Getting to steady state

Deployment runs in three rings over nine years, nearest first. Replacement begins before deployment ends: by the time the outer pickets launch, the first solar watchers are already due for renewal.

Years 0 to 2 · Helios

The solar observatory goes first: a hundred watchers around the Sun, because space weather warnings would pay the whole idea's way early.

Years 2 to 5 · Inner ring

Pickets to every inner world and the main belt; dense swarms build out at Venus and Mars while windows recur every couple of years.

Years 5 to 9 · Outer ring

The long hauls: giants, ice worlds and the deep dark. These launches spend years in cruise, so their replacement clocks start ticking before they even arrive.