Rocket silo

The rocket silo is the building used to assemble and launch rockets in Factorio. It is unlocked by its own technology, which uses all science packs except military science pack. Crafting a single rocket part requires 10 low density structure, 10 rocket fuel, and 10 processing units, for a total of 1,000 of each material to build one complete rocket.

A rocket cannot be launched until a cargo landing pad has been placed somewhere on the planet. The landing pad may be placed anywhere and does not need to be near the silo, but only one can be placed per planet. Once the rocket has a payload, it can be launched manually with the Launch button, or set to launch automatically by checking Send to orbit automatically. Launching a rocket for the first time triggers the victory screen, which thanks the player for playing and offers the options to exit, view the credits, or continue playing.

The silo accepts payloads, and one supported payload is a Satellite. Launching a rocket with a Satellite returns 1,000 space science packs to the cargo landing pad about 29 seconds after the launch is triggered. The silo’s cycle includes several distinct phases: assembling rocket parts, preparing the rocket for launch, waiting for a payload, launching, and resetting for the next cycle.

In the base game, modules and beacons can greatly improve throughput. A fully moduled silo gains +611% crafting speed from beacons and +40% productivity. The crafting phase is the only phase affected by module speed bonuses; the later animation phases are unchanged. With the best possible module setup, assembling 100 rocket parts takes 1,250 ticks, or about 20.833 seconds. The full launch cycle, including building the parts, inserting the payload, and resetting the silo, takes 3,684 ticks, or about 61.417 seconds.

The animation timings are significant when optimizing launch rate:

• Preparing the rocket for launch lasts 890 ticks.
• Inserting a Satellite takes 14 ticks with a fast inserter arm swing.
• Launching the rocket lasts 1,162 ticks.
• Resetting the silo takes 368 ticks.

In Space Age, the rocket silo can buffer a second rocket ready to load and launch. If a second rocket is already prepared, the silo skips the door close/open animation, reducing downtime between launches. In that case, only the preparing, loading, and launching phases occur. The preparing animation lasts 684 ticks, and the launch animation lasts 933 ticks, allowing a launch every 1,617 ticks, or about 26.95 seconds, assuming payload insertion is instant and the build has enough speed and productivity to sustain the needed rocket part production rate.