Factorio Space Platform Start

Start a Factorio 2.1 Space Age game stranded on a space platform. The mod changes the minimum necessary progression, recipes, and platform rules so the game can be completed without beginning on a planet.

Scenario

The player starts inside the hub of a platform named Stranded platform and cannot leave the hub.
The platform begins at the planetless Stranded in space location, in Vulcanus orbit but far away.
The nearby planet is configurable. Stranded space uses that planet's solar power and asteroid-spawn definitions and sits at the same distance from the sun (for solar).
The crashed spaceship appears to the left of the hub.
If the platform hub is destroyed, every player aboard that platform is killed.

The configured nearby planet and Nauvis remain undiscovered when their discovery technologies have not been researched.

What makes it interesting

You can not leave the hub - so no hand crafting
No storage chests and you can not extend the hub (well, until you unlock cargo bay which is basically impossible)
Asteroids might kill you before you have defenses - and the larger your base the more ammo you need
Limited space - platforms are expensive!
You need to figure out the oil processing chain which is technically vanilla but you'd never use it in normal Factorio ;)
You'll likely want to use automatic recipe switching with circuits to switch asteroid crushing recipes
You'll need to research thrusters and build them to escape. Remember thrusters need blue circuits!
Be careful to not lose items by destructing the wrong thing!

Changes to make it winnable

Without any changes, this would be impossible. These are the minimum changes to make it possible:

Starting items

1 Asteroid Collector, 1 Crusher, 4 Furnaces, 1 Assembling Machine, 2 Solar Panels

(Strictly, you'd only need one solar panel, one stone furnace but eh)

Technology progression requirements changes

These recipes are unchanged but the requirements are changed to make it possible to actually reach them.

Space Platform is researched automatically at the beginning and unlocks space platform foundations immediately.
Advanced metallic asteroid crushing triggers after producing 100 iron ore. Needed to get any copper at all which you need for all sciences.
Ice melting costs 20 red science packs and unlocks both ice melting and the Chemical Plant. Needed for steam power and (later) oil processing.
Advanced asteroid processing requires Fluid Handling and costs 200 red and green science packs. It keeps its advanced carbonic and oxide crushing unlocks, which provide sulfur and calcite.
Space coal liquefaction requires Fluid Handling and costs 100 red and green science packs. It unlocks coal synthesis and simple coal liquefaction.
Advanced Oil Processing requires Oil Processing and costs no blue science. It unlocks heavy- and light-oil cracking.
Coal Liquefaction costs 200 red and green science packs.
Oil Processing requires Space Coal Liquefaction and triggers after producing calcite.
Space Platform Thruster additionally requires Processing Unit and Electric Engine, the unlocks for its own ingredients.
Nauvis has its own discovery technology after Space Platform Thruster, costing 1,000 automation, logistic, chemical, and space science packs.

Only a single new recipe had to be added:

Carbonic asteroid stone crushing unlocks stone production as a byproduct from carbonic asteroid chunks. Needed to build furnaces.

Rule changes

Normally you can not construct Stone/Steel Furnaces or Boilers on platforms. These are allowed in this mod.
Asteroid Collector and Crusher cost what a electric mining drill normally costs.

Changes to make it enjoyable (optional, can be disabled)

Recipe and balance changes

Space platform foundation produces 6 foundations per craft instead of 1 by default; this output is configurable. (Trust me, it's unbearable with only 1 and still difficult with 6)
Coal synthesis retains the standard ingredients and crafting time but produces 3 coal per craft by default; this output is configurable.

Asteroid protection

If you start in a non-Nauvis orbit, you'll encounter asteroids. To make it possible, you need some startup time - how much time is questionable.

For the first 60 minutes by default, every damaging asteroid is replaced by two matching collectible chunks.
From 60 to 120 minutes by default, small asteroids spawn normally, medium asteroids are replaced by one matching small asteroid.
After 120 minutes, all asteroid modifications end and normal spawning resumes.

Both transition times are runtime-global settings and can be changed while a game is running. Their minimum value is 0. A zero-length protection period is skipped without displaying its protection messages.